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Keeping It FRESH: Proper Wine Storage and Maturation

Drew Horton, Enology Specialist – University of Minnesota Grape Breeding & Enology Project

One of the most important things you can do for your new wines right now is to take the proper steps to maintain their freshness. After a long year of nurturing your vines in the vineyard, and a few weeks turning their fruit into wine, now is the time to do your best to keep those wines in as optimum condition as possible during maturation and in preparation for bottling.

Maturation or aging of your wines in bulk storage is extremely important. Without proper care and maintenance, fresh, fruit-forward and youthful wine can quickly develop into a tired, oxidized and spoiled mess. There is often a misperception among novice winemakers that once a wine is fermented and racked, that merely putting the wine into barrel or tank storage will cause the wine to magically improve over time, and often for too long of a time. Though it is true that some maturation time will help the wine’s flavors and aromas to develop and “marry”, without proper control of the maturation environment a wine can change, degrade and spoil quickly.

The best friend a winemaker has at this time of year is sulfur dioxide (SO2), in the form of KMBS or potassium metabisulfite powder. There is a lot of talk going on lately about “natural wines” and the idea that the use of no or little sulfur will produce a truer or purer wine. If you are someone who likes to take chances, then go ahead and don’t use sulfur. However, if you are attempting to conduct a sustainable business that depends on a fresh, consistent, and quality product, then the judicious and proper use of sulfur is essential.

The best thing I learned while working for the world’s largest winery company is the addition of a 60 ppm dose of sulfur immediately following the completion of fermentation. That is for white wines, once primary yeast fermentation is complete, and for reds, after completion of primary and secondary (malo-lactic) fermentation. Add a dose of 60 ppm of KMBS and mix well into your wine after final transfer or racking to a storage vessel (barrel or tank).

This prophylactic high dose of SO2 will work quickly to kill or inhibit any spoilage bacteria or yeasts that may exist in your fermented wines, much like a “shock dose” of chlorine in a swimming pool.

The next considerations for the proper maintenance of stored wines are storage temperature and the need to keep vessels full. A wine in maturation-storage should be kept at 60°F or below, 55°F is best. Do your best to keep your wines in completely full vessels with little or no head-space. It is preferable to have a wine stored in various smaller vessels that are completely full than in one large vessel with too much head-space.

If you absolutely cannot avoid headspace in a vessel, then do your best to manage that space by weekly visual inspections of the wine’s surface, the regular use of an inert gas (nitrogen, argon, or CO2) to displace air (and oxygen), and to keep a proper level of free-SO2 in the wine, based on the wine’s pH. The higher the pH, the more SO2 is needed to do its job.

The reason to visually monitor the surface of a wine in storage is to ensure that no surface yeasts or molds are forming, which can lead to spoilage or increase of volatile acidity (vinegar smell). Should you notice a surface yeast or mold forming, the best thing to do is to sterile filter the wine as soon as possible to lower or eliminate the bacterial load, and to keep a proper level of free SO2 by checking it and adding it every 10 days or so.

These film yeasts can form powdery or waxy-looking surface scum on stored wine (Figure 1), and anything that is forming or floating on the surface of a stored wine should be avoided or treated. One can use a few grams of KMBS dissolved in water and applied with a spray-bottle over the surface of the wine as a way to slow-down the bacterial spoilage activity before a re-transfer or filtration.

Looking into wine fermentation vessel. Red win infected with a layer of surface mold.Red wine fermenting with a layer of surface yeast or mold 
Figure 1. Examples of film yeasts growing on red wine. Left image is looking through the bung into the carboy. Notice the waxy appearance on the photo on the right.

Certainly most wines need some maturation time, and indeed some robust reds can benefit from extended barrel-maturation for up to 2 years or more, however, a stored wine is not to be forgotten. In tank or barrel storage, the wine needs to be constantly monitored and maintained with SO2. Head spaces need to be “sparged” with inert gas on a regular schedule, and a watchful eye kept on the surface of the wine. For wine in barrels, monthly topping and SO2 maintenance, and a full rack-and-return procedure once or twice a year is highly recommended.

Now is the time to take the steps necessary to insure all your work and effort will be preserved and ready to thrill your customers with your fresh and vibrant new wines.

A chart showing proper molecular SO2 rates by pH level can be found here:

http://srjcstaff.santarosa.edu/~jhenderson/SO2.pdf

And a handy on-line SO2 addition calculator can be found here:

https://www.winebusiness.com/tools/?go=winemaking.calc&cid=15

If you have any questions or comments, feel free to contact me directly at dhorton@umn.edu, and I will do my best to help, or help to find the answers to these and any other winemaking challenges.

Publish Date: 
Friday, October 27, 2017 - 9:15am

Fall Open House this weekend!

Table Grape Matt Ericksen

Join in celebrating the fall grape harvest with an open house hosted by the University of Minnesota Grape Breeding and Enology project.  This event will feature informal demonstrations of trellis systems used in Minnesota, a refresher on grape pests and diseases, and sampling the diversity of grape varieties and breeding lines in development. You can learn about the different research projects being conducted.  Graduate student Dominique Ebbenga will give information about spotted-wing drosophila research being conducted across the state. Enologist Drew Horton will be available to answer questions about the wine making process. The open house will be from 10 am - noon on Saturday, September 9, 2017 at the Horticultural Research Center, 600 Arboretum Blvd., Chaska, MN 55318.  

Publish Date: 
Thursday, September 7, 2017 - 8:15am

2013-2016 Crush Report

Minnesota Grape Production Statistics: 2013-2016

The objective of this project was to collect harvest and pricing data for 2013 through 2016. An online survey instrument (Qualtrics) was developed to capture the current production metrics, as well as estimates of yields and pricing. Additionally, growers were asked to report on the causes and amount of crop loss experienced. Grape growers were invited through email to participate in an online survey during winter 2017. Results from the study are discussed in the following link on the Extension website.

Publish Date: 
Saturday, August 19, 2017 - 8:30am

9th Annual ICCWC Results!

iccwc-banner

Press Release

For immediate release: 8/18/17

 

Press contact: Matt Clark clark776@umn.edu, 612-626-5142

 

Kayla Forbes, MGGA Board Member and Chair of the International Cold Climate Wine Competition kmsforbes@gmail.com or iccwc@mngrapes.org

 

Trophy and Medal Winners for 9th Annual International Cold Climate Wine Competition

 

Sips, slurps, sniffs and swirls dominated the Minnesota Landscape Arboretum yesterday as 21 wine experts gathered to determine the top cold hardy wines at the 9th Annual International Cold Climate Wine Competition.

 

Six trophies are awarded to the top wines and wineries in addition to the medals. The top awards include Best-of-Show from each competition category, Winery of the Year, and Minnesota Governor’s Cup. Best of Show wines are chosen amongst the gold and double gold medal winners. Winery of the Year is awarded based on a weighted medal count. The Minnesota Governor’s Cup is chosen from the gold and double gold award-winning wines from Minnesota producers.

 

This year’s competition included 338 wines from nine states, and Ontario, Canada. The judging panel included professional sommeliers, educators, growers and winemakers amongst others.

 

The ICCWC is the only competition devoted to cold-hardy grape varietals. It seeks to honor and promote wines of exceptional quality produced in these unique cold-climate regions. The competition is run through a partnership between the Minnesota Grape Growers Association and the University of Minnesota.

 

Cold climate or cold hardy grapes are grown in regions where the better-known grapes such as Chardonnay, Merlot or Cabernet are unable to survive through the harsh weather. So in Minnesota and other northern states and Canada you will see Marquette, Frontenac, La Crescent and many other varieties. The University of Minnesota, amongst others, is a leader in breeding grapes for the harsh weather as well as suitable characteristics for winemaking.

 

Trophies

Governor’s Cup

  • La Crescent (2016) Northern Hollow Winery, Grasston, MN

Winery of the Year

  • Parallel 44 Vineyard and Winery, Kewaunee, WI

Best of Show White

  • La Crescent (2016) Parallel 44 Vineyard and Winery, Kewaunee, WI

Best of Show Red

  • Marquette (2015) Indian Island Winery, Janesville, MN

Best of Show Specialty

  • Ice Wine (2016) Parallel 44 Vineyard and Winery, Kewaunee, WI

Best of Show Rosé

  • Rosie’s Red (No Vintage) Richwood Winery, Callaway, MN

 

 

Medals

Double Gold:

Bill's Waltz

2015

Dancing Dragonfly Winery

St. Croix Falls

WI

Petite Pearl

2016

Lincoln Peak Vineyard

New Haven

VT

Ice Wine

2016

Parallel 44 Vineyard and Winery

Kewaunee

WI

Marquette

2015

Tug Hill Vineyards

Lowville

NY

Frontenac Blanc

2016

Wild Mountain Winery

Taylors Falls

MN

 

Gold:

Brianna

2016

Backcountry Winery

Stratford

IA

Wobegon White

2016

Carlos Creek Winery

Alexandria

MN

Port

NV

Chateau St. Croix Winery

St. Croix Falls

WI

La Crescent

2014

Coyote Moon Vineyards

Clayton

NY

Promenade

2016

Dancing Dragonfly Winery

St. Croix Falls

WI

2015 North Branch

2015

Grovedale Winery

Wyalusing

PA

2015 Marquette

2015

Grovedale Winery

Wyalusing

PA

Marquette

2015

Indian Island Winery

Janesville

MN

Ragtime White

2016

Lincoln Peak Vineyard

New Haven

VT

Velvet Vines Marquette

2014

Next Chapter Winery

New Prague

MN

Viking

2016

Northern Hollow Winery

Grasston

MN

Brianna

2016

Northern Hollow Winery

Grasston

MN

La Crescent

2016

Northern Hollow Winery

Grasston

MN

La Crescent

2016

Parallel 44 Vineyard and Winery

Kewaunee

WI

Ice Wine

2015

Parallel 44 Vineyard and Winery

Kewaunee

WI

Richwood Rosie's Red

NV

Richwood Winery

Callaway

MN

Petite Pearl

2015

Shelburne Vineyard

Shelburne

VT

Iowa White Blossom

2016

Tassel Ridge Winery

Leighton

IA

Tavola White

2016

Villa Bellezza Winery & Vineyards

Pepin

WI

Stinger Mead

NV

Winehaven Winery

Chisago City

MN

 

Silver:

Brut

2014

August Hill Winery/Illinois Sparkling Co.

Utica

IL

Classic White

2016

Cannon River Winery

Cannon Falls

MN

Frontenac Blanc

2016

Carlos Creek Winery

Alexandria

MN

Petit Ami

2016

Carlos Creek Winery

Alexandria

MN

Harvest White

2016

Carlos Creek Winery

Alexandria

MN

DewDrop Brut Rosé

NV

Chankaska Creek Ranch & Winery

Kasota

MN

Equinoce Extra Dry

NV

Chankaska Creek Ranch & Winery

Kasota

MN

Kasota Rose

2016

Chankaska Creek Ranch & Winery

Kasota

MN

Coeur de Colline Lot 2

NV

Chankaska Creek Ranch & Winery

Kasota

MN

La Crescent

2016

Chankaska Creek Ranch & Winery

Kasota

MN

Minnesota White

2016

Chateau St. Croix Winery

St. Croix Falls

WI

Wisconsin Red

2015

Chateau St. Croix Winery

St. Croix Falls

WI

Brianna

2016

Cold Country Vines & Wines

Kewaunee

WI

Frontenac Gris

2015

Coyote Moon Vineyards

Clayton

NY

Casa Papa Red

2013

Coyote Moon Vineyards

Clayton

NY

Apiary

2013

Crow River Winery

Hutchinson

MN

Frontenac Blanc

2015

Crow River Winery

Hutchinson

MN

2013 Marquette

2013

Dancing Dragonfly Winery

St. Croix Falls

WI

Sashay

2016

Dancing Dragonfly Winery

St. Croix Falls

WI

Golden Sunrise

2016

Danzinger Vineyards

Alma

WI

Danzinger White

2016

Danzinger Vineyards

Alma

WI

King Cranberry

2016

Danzinger Vineyards

Alma

WI

Deep Currant

2016

Danzinger Vineyards

Alma

WI

Sunburst

2016

Door 44 Winery

Sturgeon Bay

WI

Orange Cream Mead

2016

Duck Creek Vineyard and Winery

Denmark

WI

Red Neck Revenge

2016

Feather River Vineyards

North Platte

NE

Maple Reserve-Barrel Aged

 

Fernleigh Cellars

Springfield

VT

Polygon Rosé

2015

Four Daughters Vineyard

Spring Valley

MN

M-Series

2015

Four Daughters Vineyard

Spring Valley

MN

Bluff Country Blush

2016

Garvin Heights Vineyards

Winona

MN

Hawk Meadow

2016

Hawk Meadow

Hastings

MN

Hunter's Red Reserve

2015

Indian Island Winery

Janesville

MN

Frontenac Gris

2014

Javens Family Vineyard & Winery

Mankato

MN

La Crescent

2013

Javens Family Vineyard & Winery

Mankato

MN

Marquette

2016

Lincoln Peak Vineyard

New Haven

VT

Limestone

2016

Lincoln Peak Vineyard

New Haven

VT

Ridgeline

2016

Lincoln Peak Vineyard

New Haven

VT

Little Iza

2016

Millner Heritage

Dassel

MN

Sechs

2016

Millner Heritage

Dassel

MN

Bubbler

2015

Parallel 44 Vineyard and Winery

Kewaunee

WI

Blue Moon

2016

Parallel 44 Vineyard and Winery

Kewaunee

WI

Glacier Fume

2015

Parallel 44 Vineyard and Winery

Kewaunee

WI

Frontenac Blanc

2016

Parallel 44 Vineyard and Winery

Kewaunee

WI

44 White

2016

Parallel 44 Vineyard and Winery

Kewaunee

WI

Vintner's Reserve

2016

Parallel 44 Vineyard and Winery

Kewaunee

WI

Richwood Frontenac Rose

2015

Richwood Winery

Callaway

MN

River View Winery La Crosse

2015

River View Winery

La Crescent

MN

Cruisin' Wild 2016

2016

Round Lake Vineyard & Winery

Round Lake

MN

Frontenac Gris 2016

2016

Round Lake Vineyard & Winery

Round Lake

MN

Cruisin' Red 2016

2016

Round Lake Vineyard & Winery

Round Lake

MN

Brianna 2016

2016

Round Lake Vineyard & Winery

Round Lake

MN

Port

2012

Saint Croix Vineyards

Stillwater

MN

La Crescent

2016

Saint Croix Vineyards

Stillwater

MN

Marquette

2015

Saint Croix Vineyards

Stillwater

MN

SV Frontenac Blanc

2016

Schram Vineyards

Waconia

MN

Barrel 4

2015

Schram Vineyards

Waconia

MN

Marquette Reserve

2014

Shelburne Vineyard LLC

Shelburne

VT

La Crescent

2015

Shelburne Vineyard LLC

Shelburne

VT

Marquette Reserve

2015

Sovereign Estate

Waconia

MN

Marquette

2015

Sovereign Estate

Waconia

MN

La Crescent

2015

The Cape Winery

Cape Vincent

NY

Marquette Rosé

2016

The Cape Winery

Cape Vincent

NY

Three Oak Wines LaCrescent

2015

Three Oak Wines

Albert Lea

MN

Eiszider

NV

White Winter Winery, Inc

Iron River

WI

Brianna Breeze

2014

Winneshiek Wildberry Winery

Decorah

IA

 

Bronze:

 

Rhubarb

NV

Ackerman Winery

Amana

IA

Lover's

NV

Ackerman Winery

Amana

IA

Demi Sec Rosé

NV

August Hill Winery/Illinois Sparkling Co.

Peru

IL

Sec

2014

August Hill Winery/Illinois Sparkling Co.

Peru

IL

Marquette

2015

Burr Vineyards

Brandon

MN

Feisty Bitch Red

2016

Cannon River Winery

Cannon Falls

MN

Minnesota Marquette

2016

Cannon River Winery

Cannon Falls

MN

Frontenac

2014

Carlos Creek Winery

Alexandria

MN

Apple Hopper

2016

Carlos Creek Winery

Alexandria

MN

Blue Jay Edelweiss

2016

Cellar 426 Winery

Ashland

NE

Big Bold Red

2016

Cellar 426 Winery

Ashland

NE

La Crescent

2016

Cellar 426 Winery

Ashland

NE

Sweet n Sexy

2016

Cellar 426 Winery

Ashland

NE

Lone Oak Tree Vineyard Marquette

      Reserve

2015

Chankaska Creek Ranch & Winery

Kasota

MN

Marquette

2016

Chankaska Creek Ranch & Winery

Kasota

MN

Petite Colline

2016

Chankaska Creek Ranch & Winery

Kasota

MN

Wild River Rose

2015

Chateau St. Croix Winery

St. Croix Falls

WI

Thoroughbred Red

NV

Chateau St. Croix Winery

St. Croix Falls

WI

Northern Lights

2016

Cold Country Vines & Wines

Kewaunee

WI

Red Sunset

2016

Cold Country Vines & Wines

Kewaunee

WI

Brianna

2013

Coyote Moon Vineyards

Clayton

NY

Twisted Sister

2016

Coyote Moon Vineyards

Clayton

NY

Razzle Dazzle

2015

Coyote Moon Vineyards

Clayton

NY

Marquette

2014

Coyote Moon Vineyards

Clayton

NY

Township

2013

Crow River Winery

Hutchinson

MN

Christine's CanCan

2015

Dancing Dragonfly Winery

St. Croix Falls

WI

Marquessa

2015

Dancing Dragonfly Winery

St. Croix Falls

WI

Marquette

2016

Danzinger Vineyards

Alma

WI

Waumandee White

2016

Danzinger Vineyards

Alma

WI

Cresent Moon

2016

Danzinger Vineyards

Alma

WI

M

2016

Door 44 Winery

Sturgeon Bay

WI

Sparkler

2015

Door 44 Winery

Sturgeon Bay

WI

Snowy White

NV

Falconer Vineyards Winery & Cidery

Red Wing

MN

Lumberjack Hard Cider Barrel Oaked

NV

Falconer Vineyards Winery & Cidery

Red Wing

MN

Edelweiss

2016

Feather River Vineyards

North Platte

NE

Maple Reserve-Amber

NV

Fernleigh Cellars

Springfield

VT

Frontenac

2015

Fireside Winery

Marengo

IA

Marquette

2016

Flower Valley Vineyard

Woodbury

MN

Sparkling Brianna

2016

Four Daughters Vineyard

Spring Valley

MN

La Crescent

2015

Four Daughters Vineyard

Spring Valley

MN

The Digger's Dance

NV

Fresh Tracks Farm LLC

Berlin

VT

Maple Wine

NV

Fresh Tracks Farm LLC

Berlin

VT

Marquette

NV

Fresh Tracks Farm LLC

Berlin

VT

Huntsville Red

2016

Grape Mill Vineyard & Winery

East Grand Forks

MN

Brianna

2016

Grape Mill Vineyard & Winery

East Grand Forks

MN

2014 Late Harvest Frontenac Gris

2014

Grovedale Winery

Wyalusing

PA

2016 Frontenac Gris

2016

Grovedale Winery

Wyalusing

PA

2013 Marquette

2013

Grovedale Winery

Wyalusing

PA

Village Marquette

2016

Indian Island Winery

Janesville

MN

Brianna

2016

Indian Island Winery

Janesville

MN

Marquette

2013

Javens Family Vineyard & Winery

Mankato

MN

New Traditions

2014

Javens Family Vineyard & Winery

Mankato

MN

Nawadaha Falls

2016

Leigh's Garden Winery, Inc

Escanaba

MI

Black Sparrow

2016

Lincoln Peak Vineyard

New Haven

VT

La Crescent

2016

Lincoln Peak Vineyard

New Haven

VT

Marquette Nouveau

2016

Lincoln Peak Vineyard

New Haven

VT

Müllner Weiss

2015

Millner Heritage

Dassel

MN

Róna

2014

Millner Heritage

Dassel

MN

Schnickelfritz

2016

Millner Heritage

Dassel

MN

Gemütlichkeit

2016

Millner Heritage

Dassel

MN

Minnesota Crisp

2016

Millner Heritage

Dassel

MN

Velvet Vines Frontenac Gris

2015

Next Chapter Winery

New Prague

MN

Aurora Red

2016

Northern Hollow Winery

Grasston

MN

Drink Pink

2015

Parallel 44 Vineyard and Winery

Kewaunee

WI

Frozen Tundra Red

2016

Parallel 44 Vineyard and Winery

Kewaunee

WI

Frontenac Gris

2016

Parley Lake Winery

Waconia

MN

Brianna Breeze

NV

Parley Lake Winery

Waconia

MN

Barn Quilt Red

2016

Parley Lake Winery

Waconia

MN

La Crescent

2016

Parley Lake Winery

Waconia

MN

Marquette

2016

Parley Lake Winery

Waconia

MN

Lake View White

2016

Parley Lake Winery

Waconia

MN

Barn Quilt Red Limited Edition

2015

Parley Lake Winery

Waconia

MN

Potter Settlement Frontenac Gris

2016

Potter Settlement Artisan Winery

Tweed

Ontario

Potter Settlement Marquette

2016

Potter Settlement Artisan Winery

Tweed

Ontario

Skinny Dipping: Sundance 2016

2016

Round Lake Vineyard & Winery

round lake

MN

TropicalPassion2016

2016

Round Lake Vineyard & Winery

round lake

MN

Frontenac Gris

2015

Saint Croix Vineyards

Stillwater

MN

Windsock White

2015

Schram Vineyards

Waconia

MN

Marquette Single Barrel

2014

Shelburne Vineyard LLC

Shelburne

VT

Whimsey Meadow Rosé

2016

Shelburne Vineyard LLC

Shelburne

VT

Marquette

2015

Shelburne Vineyard LLC

Shelburne

VT

Louise Swenson

2016

Shelburne Vineyard LLC

Shelburne

VT

St. Therese Rose

2015

Sovereign Estate

Waconia

MN

Frontenac Blanc Reserrve

2015

Sovereign Estate

Waconia

MN

La Crescent

2015

Sovereign Estate

Waconia

MN

Iowa Edelweiss

2016

Tassel Ridge Winery

Leighton

IA

Iowa Brianna

2016

Tassel Ridge Winery

Leighton

IA

Candleglow White

2016

Tassel Ridge Winery

Leighton

IA

Frontenac

2016

The Cape Winery

Cape Vincent

NY

Tibbetts Point Misty Whte

2016

The Cape Winery

Cape Vincent

NY

Compass Red

2015

The Champlain Wine Company

Plattsburgh

NY

Master's Cuvée

2016

The Winery At Kirkwood

Cedar Rapids

IA

Blue Bell Sparkling

2015

The Winery At Kirkwood

Cedar Rapids

IA

Master's Cuvée Blanc

2016

The Winery At Kirkwood

Cedar Rapids

IA

Summer Sabbatical

2016

The Winery At Kirkwood

Cedar Rapids

IA

Three Oak Wines Marquette Rosé

2015

Three Oak Wines

Albert Lea

MN

Bubbly Brianna

NV

Tug Hill Vineyards

Lowville

NY

Strawberry Rhubarb

NV

Tug Hill Vineyards

Lowville

NY

Prairie Star 2016

2016

Tug Hill Vineyards

Lowville

NY

La Crescent 2016

2016

Tug Hill Vineyards

Lowville

NY

Marquette

2015

Two Rivers Vineyard & Winery

Ramsey

MN

Marquette Reserve

2013

Villa Bellezza Winery & Vineyards

Pepin

WI

La Crescent

2015

Wild Mountain Winery

Taylors Falls

MN

Frontenac Gris

2015

Winehaven Winery

Chisago City

MN

Edelweiss

2015

Winehaven Winery

Chisago City

MN

Rhubarb Wine

NV

Winehaven Winery

Chisago City

MN

Lakeside Red

NV

Winehaven Winery

Chisago City

MN

Raspberry Wine

NV

Winehaven Winery

Chisago City

MN

Marechal Foch

2016

Winehaven Winery

Chisago City

MN

La Crescent

2016

Winehaven Winery

Chisago City

MN

Strawberry-Rhubarb Wine

NV

Winehaven Winery

Chisago City

MN

Farmers Daughters

2015

Winneshiek Wildberry Winery

Decorah

IA

Cranberry Crush

2015

Winneshiek Wildberry Winery

Decorah

IA

 

 

International Cold Climate Wine Competition | mngrapes.org/competition

 

Publish Date: 
Friday, August 18, 2017 - 4:00pm

2017 Grape Harvest Preparation 

Matt Clark, PhD., Project Director & Drew Horton, Enology Specialist

Here are a few practical and easy-to-do things to get your wine production operations prepared and ready for a safe, happy, and healthy wine harvest.

Order early

Order your winemaking ingredients early. Some providers will give you a discount of some kind, or free shipping, if you order early. Another reason to order early is that some items are more popular, or certain sizes are limited, and if you wait until the last moment they may be out or back-ordered. Thinking about your order will also force you to really consider the amount and types of winemaking you expect to do in a given season, and to organize those thoughts in the amount and type of things you use: yeasts, nutrients, enzymes, stabilizers/clarifiers, pressing aids, tannins, etc. Most ingredients have expiration dates, properly sealed and stored leftovers can be used again the next year or two. Double check what you are using and for what purpose. Some ingredients may sound the same but have different purposes, such as yeast hydration nutrient and fermentation nutrient.

All of the above comments apply to your barrels as well. Not every barrel is in stock or on-the-shelf here in the USA and shipping barrels cheaply takes time. Again, it makes you think ahead about how many and what type of barrels you should be considering for the type of wines and batch sizes you will be making. And don’t forget to order enough barrel racks, an extra rack or two can be handy for splitting up odd number barrel lot sizes in your cellar.

Get to know your grapes

Get your grape purchase contracts and agreements settled and signed off now, or make those hand-shake deals when you know you can. Don’t wait until the last minute to start thinking about where you will get fruit. By this time of year, after fruit set, growers should have a pretty fair idea of what and how much of each varietal they will have available. The best practice is to make all these arrangements in person. Spend the time to walk the vineyards you are interested in. It forces you to actually look at the vineyard and the vines, to taste and smell after veraison, and to get to know better your primary ingredient and the people who grow it. Check with previous wineries the grower may have sold to in previous years. Don’t (always) rely on a grower to provide you with good quality harvest chemistry data, go out yourself, pick your own samples, and make your own measurements. It is good practice, strengthens the relationship with the grower, and will prepare you for all the lab work coming soon.

Get your lab working

Speaking about lab work and testing of juice and wine, you really do not have a more important winemaking tool than a modern, quality and reliable pH meter. The acids in juice and wine are important, and pH is without question the one winemaking parameter you can’t know enough about. A pH meter and probe require special care, and not just during harvest, you should be using it the year around, and keeping the probe maintained and cleaned. Having a spare probe on your shelf is worth consideration. Throw out your old calibration buffer solutions and buy new ones, every six months is recommended. It is also a good idea to check your pH meter’s accuracy by comparing it with another’s, either a lab or another winery or brewery’s. It is not unheard of to have two meters in one winery.

Preventative maintenance

Check and maintain your processing equipment, and order certain normal-wear parts ahead of time; O-rings, gaskets, seals, etc. Depending on the make, style, and supplier of your press, you should either have a spare bladder or membrane, and a repair kit, in-house, or confirm that your press supplier can get you a new one within 24-hour shipping. If any of your equipment comes directly from Europe, keep in mind the whole place is on vacation in August! This advice also applies to your pumps, keep a spare impeller or diaphragms (and/or other parts) in-house, and take your pumps apart to clean and lubricate now while you have the time.

Make sure you have the right tools to maintain your equipment, and use them now to tighten or replace loose or missing screws, bolts, seals, flanges, belts, etc. Make sure you have grease, and grease gun(s); food-grade for your press, de-stemmer/crusher and pumps, and normal shop grease for other mechanical non-food contact equipment. Remember to make it a daily or weekly routine to use those grease guns especially on press and de-stemmer/crusher bearings. If you have a fork-lift or other device, an annual service in late July or early August is also good practice. Hydraulic systems and seals should be operated and checked, and you should have some extra hydraulic fluid in-house. Find out where the closest mechanic or auto shop that can repair a blown hydraulic hose is, you will be glad you know this in advance. And if your equipment requires metric tools, have them on hand before you need them.

Get your air-cooling and temperature control systems inspected and maintained. Make sure you form a good, positive and long-lasting relationship with your local HVAC technician, a person who can be a critical player in the success of your winemaking (as these systems only fail on Sunday afternoons and holidays). Check, clean and/or replace air filters as needed in all your ventilation, heating, cooling, and chilling systems.

If you are using “floating lid” variable capacity tanks, consider buying new lid-gaskets each or every other year. These types of lids have been found to be an entry for oxygen, bacteria and spoilage organisms unless they are rigorously maintained, cleaned and sanitized. During fermentation, don’t use them, use plastic sheeting and a string and bungee cord combo, the fermenting wine will be protecting itself from oxidation by its own production of CO2 gas. When you are using these lids, keep in mind the air-pump, hoses, hose-clamps and fittings can fail, and the pressure-gauge needle can get “stuck” and give erroneous readings. It is best practice when using floating-lid tanks to manually and visually check the lid-seal (not just the gauge) every day, do less at your own peril. When storing the lids, take all of the pieces apart and the gasket off the lid, and clean and sanitize them before putting them away.

Safety training

Make sure your crew has important foundational and on-going safety training of some kind, and that this training is documented. Do not allow untrained personnel to operate or clean hazardous equipment without proper personal protective equipment and safety training, including “lock-out/tag-out” procedures. A lot of winery equipment is very capable of doing grave damage to body parts. With names like “crusher” and “press” you don’t have to look far to identify safety issues. Make sure anyone using pallet-jacks knows proper and safe operation, and anyone using a forklift had better be certified, every three years, your insurance company probably requires it as does MNOSHA. Wearing open-toed shoes or sandals should not be allowed while working in a winery.

CO2 gas produced by active fermentation can kill a worker in a few seconds, make sure all winery staff (including hospitality staff) knows about the practical considerations of CO2 gas causes and effects, and how to properly ventilate an actively fermenting cellar. Every year somewhere in the world workers are asphyxiated by CO2 gas in wineries. Many winery tanks can be considered confined spaces, and you should be aware of proper and safe confined space operations. Confined space training, documentation, and permitting may be required depending on various considerations, be aware of what this is all about, and consider starting your own simple and effective confined space procedures and protocols as needed. For further information about Confined Space considerations see this MNOSHA Hazard Safety Alert, or contact MNOSHA at 877-470-6742: https://mn.gov/admin/assets/hazalert_confinedspace_tcm36-207158.pdf

 

 

 

 

 

 

 

 

Publish Date: 
Friday, June 16, 2017 - 2:30pm

9th Annual ICCWC

ICCWC

Registration is open for the 9th annual International Cold Climate Wine Competition (ICCWC)! The competition will be held on August 18, 2017 at the Minnesota Landscape Arboretum in Chaska, MN and will be host to another year of Cold Climate Wine innovation and excellence. The Cold Climate Wine industry is continuing to grow and this competition has been instrumental in establishing a standard of quality. We cordially invite all Cold Climate commercial wineries to enter their wines into the competition. Remember, this is the only wine competition where the judges don't blink twice when you say Marquette, Frontenac, or La Crescent.

The average wine buyer isn't going to know from the outside what a wine actually tastes like.  Sometimes clever names or attractive labels are all it takes to sell some bottles of wine. Winemakers, however, would always rather have a great tasting wine rather than a good looking bottle.  So, in a blind tasting the judges never see the labels.  They simply taste the wine.  

At the International Cold Climate Wine Competition (ICCWC) the judges are internationally recognized experts in evaluating cold-climate wines.  They already know that award-winning wines are created from grape varieties that survive temperatures of -20º or lower.  This is your chance to have these independent judges evaluate wines you have made from cold-climate grapes.

A list of all accepted varieties and a full list of rules are available on the Minnesota Grape Growers Association (MGGA) registration website. All commercial wineries are invited to enter wines made up of a minimum of 75% cold-hardy varieties.

Wines are awarded gold, silver and bronze medals, and best of show awards to the top red, white, rosé, and specialty wines. The annual "Governor's Cup" is awarded to the judges’ favorite Minnesota wine. Finally, the "Winery of the Year" award will be presented to the winery with the best overall showing at the 2017 competition. Medal and award winners will be posted online, and many medal winners will have a chance to be featured during the 2018 Cold Climate Conference in March.

Online registration is open now. Reduced rate registration ends July 1, 2017. Final deadline for registration is August 7, 2017. To register, please visit www.mngrapes.org/iccwc. Wines must be postmarked or delivered in-person by 4:30pm CDT on August 7, 2017 to qualify.

The ICCWC is a partnership between the Minnesota Grape Growers Association and the University of Minnesota.

          

 

 

Publish Date: 
Friday, June 16, 2017 - 2:30pm

Minnesota Wine Events Sign-up Now!

Click on the Banner Links to Learn more and register!CCC 2017

Winter Wine Fest

Publish Date: 
Wednesday, February 8, 2017 - 11:00am

2016 Fall Vineyard Tour

Matthew Clark, Assistant Professor

About 65 people attended the annual Grape Fall Tour hosted on September 10 at the Horticultural Research Center. The 2 hour event included sampling grapes from the research vineyards, learning about insect and disease pests, demonstrations in the field, as well as a short lecture on soil nutrition as it relates to winemaking.

John Thull Field day Itasca

John Thull discusses the University of Minnesota cultivars, including Itasca.

Attendees were welcomed at the registration table and given a new copy of “Growing Grapes in Minnesota”, which was hot off the press that morning.  The updated manual published by the Minnesota Grape Growers Association is a modernized version of the best practices guide, complete with spiral binding, color images, updated tables, new content, and web resources.

The event started with a brief introduction of the staff and a review of the year’s events.  Dr. Clark described research findings on wine making, genetic work for disease and insect resistance, the release of the ‘Itasca’ grape in 2016, and plans for the future which include additional focus on breeding table grapes.

Table Grape Matt Ericksen

Attendees sample a selection of cold hardy and cold tender table grapes

An open grape tasting was held which allowed the attendees to try a curated collection of fruit grown at the HRC.  Jenny and John Thull selected samples to reflect unique attributes of the fruit that are important in wine making and targets for the breeding program.  This included Vitis vinifera samples that are familiar to wine drinkers worldwide. In addition there were high tannin varieties to help the tasters experience how the juice (and later the wine) interacts with the mouth.  There were also samples of Vitis labrusca hybrids and cultivars, primarily from Elmer Swenson breeding material.  Additional, a table we set with ‘muscat’ varieties, which have unique flavors and aromas that are different from the other hybrids and are often desirable in table and wine grapes.  A selection of table grapes were often shown.  Unfortunately, many of these do not perform well in Minnesota without protection or growing strategies to reduce winter injury (such as burying the vines). Of course, the common wine cultivars grown in Minnesota were available for tasting.  Some new breeding selections were also on display. 

Professor and Department Head, Carl Rosen, of the Dept. of Soil, Water, and Climate, gave a short lecture on vine nutrition and its effects on wine and juice.  This was a brief report at the conclusion of the Northern Grapes Project (northerngrapesproject.org). 

Carl Rosen

Dr. Carl Rosen decribes the research findings about vine nutrition to the audience as a follow up to the Northern Grapes Project.

The HRC staff demonstrated new bird netting equipment that was donated by Plantra which allows for easy over-the-vine netting to be deployed with three laborers.  The pull-behind device uses a reusable, soft knit net called AviGard® Flex™ Diamond Mesh Net. Also on display were bins and other equipment from MDT and Associates.  Finally, the attendees were able to walk through some of the vineyards and see young plantings of ‘Itasca’ and ‘Marquette’ grown in VSP.

Plantra netting demo

Demonstration of the Plantra netting equipment

2016 staff

Photo of the 2016 field crew: Matt Ericksen, Rajmund Eperjesi, Laise Moriera, Matt Clark, Jenny Thull, John Thull. Photo credits to Julian Silva
Publish Date: 
Wednesday, December 28, 2016 - 3:45pm

Winter weather is here! What does this mean for the vines?

John Thull, Vineyard Manager

Matt Clark, Assistant Professor, Extension Specialist

Tracking the weather conditions at each vineyard site is something that growers should be doing over the winter months. Despite most of the grape varieties being ‘cold-hardy’, winter injury can come in many forms and cause damage.  Winter injury can result from large shifts in temperature (more common in South Dakota), low temperature injury, repeated low temperature injury, bare soils, wind damage, and late spring frosts.  Not only are vines impacted, but winter conditions also have a role in insect population life cycles.

The snow that most of the state received this past weekend (12/10-12/11) is well timed to provide insulation for the roots and bases of the vines.  However, most of the vine is still above the snow-line and therefore these parts (trunks, cordons, canes) will be exposed to the low temperatures coming during the next couple of months. A pending polar vortex this week is predicted with lows in the negative single digits (Fahrenheit), something most cold-hardy hybrids should be able to endure if they had sufficiently acclimated for winter by responding to the shorter days and cooler temperatures.

How much cold a vine can endure depends on the state or condition of that vine going into winter. Stresses and environmental conditions from that growing season (rainfall amounts, growing degree days, solar radiation intensity, crop load, etc.) vary from year to year. Therefore, the cold temperature minimum that a vine can tolerate before suffering little cold injury will naturally change every season as well. For example, some years Frontenac can see -30°F with little or no damage and other times we may see Frontenac getting damaged already in the -20's range.

Without snow cover, the roots of the vines may see some damage, especially on newly planted vines, which can lead to symptoms of stunted growth and/or nutrient deficiencies in the next season. With a delivery of snow, the temperature drop below zero for a few days should have less of an impact.  However, this may also favor Japanese beetle grubs which will also benefit from the insulation effects of the snow.

Monitoring the weather and vine health throughout the winter may seem like a chore, but it can help to set the vineyard manager up for success for the coming spring.  For example, monitoring bud survival through the winter can inform pruning in the spring.  Weather monitoring (all season long) is one of the best tools for understanding the yearly variation and to help in predicting insects, diseases, and also injury during the dormant season. Keeping these events in mind will help growers understand why their vineyards behave as they do during the upcoming growing season.

Publish Date: 
Monday, December 12, 2016 - 10:15am

Wine maker's nightmare:  Re-fermentation and unstable sweet wines, and how to avoid.

Drew Horton, Enology Specialist

Matt Clark, Assistant Professor

12/8/2016

No doubt about it, one of the worst things that can happen with a wine is re-fermentation in the bottle. Instead of a beautifully-colored wine with brilliant clarity, you discover a once-perfect wine has become cloudy and bubbly, or even worse, numerous "bottle bombs" are exploding in the cellar or on winery or retail shelves, or at the least, corks are pushing  out of the bottle. This is a disaster.

Whenever there is any amount of unfermented sugar in a bottle of wine, the wine risks re-fermenting. This article is really about sweet white or rosé wines, but also applies to any non-dry red wine as well.

There are a variety of methods, techniques and additions that can help eliminate or reduce this risk.

Firstly, overall winery sanitation is the most important. Each and every surface; tank, pump, hose, valve, bottle-filler, or corker that comes into contact with wine must be clean and sanitized. There are many ways to sanitize, but none of them will work unless the surface is first cleaned. Cleaning is the removal of dirt or other residue from a surface, sanitizing is the killing of all microbes on a surface. A wine maker needs to do both when handling any sweet wine.

When preparing a wine for bottling, the first step after blending (if any blending is to be done) is to treat the wine with bentonite, which removes excess protein and keeps the wine heat stable.  A complete and exhaustive article on the use of bentonite is available on the internet, posted by Purdue University Extension: https://www.extension.purdue.edu/extmedia/fs/fs-53-w.pdf

After the bentonite treatment, some method of achieving cold-stability must also be done. Traditional cold-contact treatments are the norm, but they do require the wine be super-chilled. This means bringing the wine close to, or just at, freezing for a period of 5 to 15 days, depending on the amount of excess tartaric acid in the wine, among other variables. It should be noted that there are new preparations of manno-proteins and cellulose that can provide almost instant cold-stability, but they lack the often-beneficial side effect of traditional cold-contact stabilization which can reduce the overall total acidity in a wine by precipitating excess tartaric acid in the form of crystals. See this link to the Laffort website for alternate cold-stabilization methods and products: http://laffort.com/en/products/stabilisation  

Electrical conductivity tests can be done by a laboratory to confirm that cold-stability has been achieved. In the Midwest, Iowa State University's Midwest Grape & Wine Industry Institute can conduct this testing quickly and for a small fee, see this link to their Lab services order form: http://www.extension.iastate.edu/wine/sites/www.extension.iastate.edu/files/wine/PriceList-May%202016.pdf

The addition of a sweetener (sugar, sweet reserve juice, or concentrate) should happen late in the wine preparation process, usually between a nominal rough and polish filtration step is best.  Any extra time a wine is in storage with any sugar it risks re-starting fermentation. During the aging and storage period for a wine with existing natural residual sugar, you are advised to pre-filter the wine and keep the wine at a cold-enough temperature (45F degrees or less) and with sufficient free sulfur (based on wine pH) in order to inhibit re-fermentation.

So, with this now blended, heat and cold stabilized wine, you are ready to start final filtration and any final sweetening.  Keep in mind when discussing filtration that there are both "nominal" and "absolute" filtration equipment and techniques. Nominal  filtrations are achieved by the use of sheet or pad filtration, sometimes used with DE (diatomaceous earth), in a plate and frame type of filter. Cross-flow filtration, though it does not require DE or filter sheets, is also to be considered a nominal filtration and not "absolute".

Nominal filtration (sometimes called depth filtration) will remove 99.9% of bacteria and yeast cells. Only absolute (aka sterile membrane) filtration will keep the wine 100% free of bacteria and yeast cells. Sterile membrane filter cartridges and housings are not inexpensive, and they must be integrity-tested both before and after use. If a wine is not pre-filtered well, membranes will plug quickly. Here is a link to the bubble-point method to test sterile cartridge membrane integrity: http://www.scottlab.com/uploads/documents/downloads/25/ScottCart%20Bubble%20Point%20Test%20.pdf

In lieu of the use of absolute sterile membrane filtration, and the use of strict chemical or heat sterilization of all bottling/capping/corking equipment, you can consider the use of a yeast fermentation inhibitor such as Sorbic acid, usually used in the form of powdered Potassium Sorbate. The big issue with sorbate is that it does not guarantee stabilization, and it must be used properly and in conjunction with proper levels of free sulfur. Also, if used in large amounts, or in a wine that may undergo spontaneous malo-lactic fermentation, there is a risk of "geranium-smell taint." Also, above a certain level, some consumers will notice the smell and taste of sorbate. Here is a link to an article on the nature and proper use of sorbate : http://www.extension.iastate.edu/wine/sites/www.extension.iastate.edu/files/wine/SorbicAcid1.pdf

If you are able to produce a sweet wine with alcohol at or above 13% and a pH below 3.5, then sorbate may be an option to help stabilize the wine without the use of absolute sterile membrane filtration, and without the risk of geranium taint. A low alcohol wine (say 11% or below) with high pH (above 3.6) and any amount of residual sugar is virtually impossible to stabilize and guarantee stability without the use of a high-speed bottling line utilizing integrity-tested absolute sterile membrane filter equipment.

Keep in mind, though, that an absolute sterile membrane is only a doorway, with dirty on one side and sterile on the other. Any downstream equipment (i.e., post-membrane), such as valves, hoses and bottle-filler that are not also completely sterile, can allow even a few bacteria or yeast cells to enter the bottle, and can lead to re-fermentation. If you have ever spent a few hours, or days,  "de-corking" and attempting to re-treat and re-bottle a wine that has become unstable or is re-fermenting, you will take the preceding to heart.

 

 

Publish Date: 
Thursday, December 8, 2016 - 8:00am

Pages

Registration is now open for the 9th Annual International Cold Climate Wine competition. Click on the logo to learn more.

ICCWC

Winter is Minnesota can be one of the most challenging times for the grape plants.  It's the main reason V. vinifera varieties aren't grown here.  Learn a little bit about whats going on in the vineyard in winter.

Wine making is a rewarding career, but is not free from headaches. A wine maker's nightmare is the re-fermentation of sweet wines and the instability of some wines. This blog entry addresses the topic and offers some strategies to avoid and mitigate a potential devastating re-ferment.

 

Are you curious if your wine is finished with malolactic fermenation? Here is a quick reminder on how to test with paper chromatography

chromatograph

 

 

 

ALERT: September 27, 2016. Spotted Wing Drosophila (SWD) in Grapes: A short memorandom on SWD in Minnesota and associated volatile acidity. Read more here

Fall vineyard managment should focus on managing insects, vertebrate pests, rots, and diseases that will impact the vines in the next growing season.  Making quality wines requires disease intervention and sorting, as infected fruit will impact wine quality. Read more here.

 

International Cold Climate Wine Competition 2016 Results here!

Northern Grapes Project Webinar Registration

“From Vine to Glass: Understanding the Flavors and Aromas of Cold-Hardy Grapes and Wine”
Tuesday, May 17th*, 2016
12:00 Noon Eastern (11:00 am Central)
7:00 pm Eastern (6:00 pm Central)
*Please note this is a date change from the original date of May 10th.

Join Anne Fennell of South Dakota State University, Adrian Hegeman of the University of Minnesota and Somchai Rice of Iowa State University as they discuss their research conducted on Marquette and Frontenac as part of the Northern Grapes Project. 

Mock Winery Inspection

Friday April 29, 2016

 

Savor Minnesota

This Saturday April 16, 2016

 

Itasca Grape Vine Named

The University of Minnesota releases its news wine varieity 'Itasca' on April 4, 2016

 

Intergeneric Grafting

Experimenting with different grafting techniques including grafting Ampelopsis with a hybrid rootstock.

Preliminary Bud Survival Data

Early bud chop counts on cold-hardy cultivars at the HRC

 

Old blog entries

Are you looking for previous blog posts? Search the archived entries