Yesterday we harvested all the Marquette out at the Horticultural Research Center (HRC). Since I haven’t written anything about this grape, I figured now was a good time to write a little post on it. I really like the potential we have with Marquette. When it’s done right, it makes a lovely dry red wine with similar aromas to Gamay or Pinot Noir. Unlike these two grapes, however, Marquette is a teinturier variety so it is very highly pigmented. Like Pinot Noir, it is low in tannin.

Like many of our Vitis riparia-based hybrids, it leans toward high sugar and high acidity.  All of our Marquette harvested this year came in with an average Brix of 26, and a TA around 10.o g/L. Obviously a red wine with 14-16% alcohol and searing acidity (those acid numbers are more typical to Riesling) doesn’t sound all that pleasant, but with some slight adjustments, it makes a nice red wine.  Here’s a summary of previous harvest data with Marquette at the HRC. As you can see, high sugar and high acidity. In good years, it comes in with a more manageable TA of less than 10 g/L:

Here’s what we’re working on in our optimization trials with Marquette this year:

1) Ways to increase tannin concentration/extraction

We divided one lot into 3 different fermentations. Last year we experimented with leaving 50% whole clusters (uncrushed) for one Marquette fermentation, and the results showed a marked increase in tannins. The flavor and structure of the resulting wine was nice, although I think it would be a good blending component rather than a wine to drink on its own. We are trialling this technique again this year. However, we didn’t have the ripeness that we had last year, so I imagine we’re going to have a bit more “green” character to the wine. It will be good to have a comparison over different vintages, regardless. With a second trial, we removed 20% of the volume of juice from the must in hopes of concentrating the tannins that are extracted.  In the third trial, we froze the grapes solid (at -20°C), hoping to rupture the cells in the skins and seeds to facilitate tannin extraction. We’ll keep you updated as to how the resulting wines turn out.

2) Yeast Trials

We have been pretty happy with the results of using yeast strain D254 on Marquette. It tends to help bring out the black pepper aroma in the grape, and minimizes any green/herbaceous character. We  are doing more trials with D254 this year, but also threw in two Burgundy yeasts: RC212 and RA17. Because of the high potential alcohol of our Marquette, we bled off a portion of the juice (about 15%) from the must, and added an equivalent amount of distilled water back to the must in order to bring the Brix down to 22 (a fairly standard practice in warm regions with high sugar levels). This had the double effect of also bringing down the TA a bit to around 8 g/L. Using distilled water ensures that there is only a negligible increase in pH.  By removing a portion of the juice prior to the amelioration, we hope to keep the skin/juice ratio the same. This will hopefully help diminish any perceived dilution of flavors.

3) Sparkling Rose

With all the juice that we ‘bled’ from our Marquette, we decided to make a sparkling rose. We will be making it using “Methode Ancestrale” rather than the Champagne method. In this method, fermentation is stopped by chilling the wine to zero celsius about half-way through fermentation.  The nearly clear wine is then racked, and allowed to restart and complete fermentation in bottle.  Usually there is a negligible amount of lees remaining, so the wine doesn’t need to be disgorged. I’m planning on having a finished wine with about 12% alcohol, 9 g/L TA, and 50 g/L residual sugar. We’ll see how it goes…