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Fermentations

by George Balling
| December 8, 2010 8:00 PM

Winemakers are faced with a myriad of decisions during the process of creating their final product. When to harvest and at what sugar and acid levels? Should we pick during the night, early morning or late in the day? What kind of oak barrels to use if any at all? These are just a few of the issues that must be decided on, all of which influence greatly the taste of the wine that goes in the bottle and eventually reaches you the consumer.

While every one of these decisions is important some of the most crucial ones occur during fermentation as the yeast consumes the sugar and creates alcohol, and many of the basic flavors of the wine are created. Yeast is a good place to start. You might think that yeast is yeast, but actually it can greatly influence the flavors and aromatics of the wine. An anecdotal story from my past work at a California winery will illustrate the point.

While at Balletto Vineyards the winemaker Dan Cedarquist and I were working on designing a new dry rose of Pinot Noir for the Balletto portfolio. We tasted through a number of roses we liked and some we did not to refine our ideas for the flavor profile of the Balletto. Prior to this exercise I, like many, did think yeast was yeast. During the conversation, Dan suggested we use a yeast strain from South Africa to capture some of the Provenal character we were seeking and sure enough that did it. We loved the wine and others did too, as it quickly sold out and went on to take a gold medal at the San Francisco Wine Competition. Moral of the story being that yeast is not just yeast and is a big decision for many winemakers.

Another big question comes down to how to crush the grapes to get the juice out of them and allow the yeast to work its magic. The most expensive process is to use free run juice, meaning no crush but to let the weight of the grapes sitting on top of each other in the fermenter to slowly and naturally "push" the juice from the skins and crush the grapes.

Another version of this that is even more costly is whole cluster fermentation where the bunches go into the fermenter still attached to the stems. It is believed if you use these methods you get more natural flavors from the grapes, one I would agree with. You do however loose more juice from the lack of crushing.

How much fermentation is another big question. While all red wines go through primary and secondary fermentation called malolactic fermentation, many white wines are not allowed to go through the secondary stage. This secondary fermentation converts malic acid (a fruit acid) to lactic acid (a milk acid). In red wines it is covered up by the bigger richer flavors of the varietals. In Chardonnay though it is what produces the butter note that is so popular in that varietal. In most other white wines it is less desirable as crispness is more sought after.

Also, once you stop the fermentation you face the decision to leave the wine in contact with the dead yeast cells or lees, therefore extracting more yeasty flavors.

We did receive a question from one of our regular readers about the presence of lactic acid in wine as a source of allergens that could cause trouble for those who are lactose intolerant; The question was in fact the inspiration for this article. There is actually a two part answer on this, first the levels of lactic acid in wine is relatively low and unlikely to cause allergic reactions. Secondly, most folks are allergic to lactose not the lactic acid by product. While it is possible that could trigger an allergic reaction most allergies to wine come from either sulfites or tannins. You can refer to my previous article about wine allergies on the blog at our website www.thedinnerpartyshop.com .

The length of time the wine is left in contact with the skins, seeds and stems is another choice winemakers face. While white wines are not fermented on the skins red wines always are otherwise there would be no color to the wine. If you squeeze the juice from any red grape it will run clear; it is only through the skin contact that the wine gains color. The longer the fermenting grapes stay in contact with the solids, and the more frequently the "cap" or floating layer of solids is "punched down" through the fermenting juice, the darker the color, and the more tannin and flavor is extracted from the solids.

As consumers it is most important is to identify the wines you like best and then talk to your preferred wine professional as they will be able to help you select wines that go through similar processes and where the winemakers have made similar decisions. This allows you to continually try new things, the best part for many wine drinkers, but also to consistently find wines you like.

If there is a topic you would like to read about or questions on wine you can e-mail George@thedinnerpartyshop.com or make suggestions by contacting the Healthy Community section at the Coeur d'Alene Press.

George Balling is co-owner with his wife Mary Lancaster of the dinner party a wine and table top decor shop in Coeur d'Alene by Costco. George is also the managing judge of The North Idaho Wine Rodeo. www.thedinnerpartyshop.com .

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