How Insects in The Vineyard Help With Wine Complexity

I recently came across an article about wasps and how they help with creating complex wines.  The article can be found here: Thank The Simple Wasp For That Complex Glass of Wine, found on NPR’s website.  This article was interesting to me because I had never heard of wasps and hornets benefiting wine before; ladybugs, yes, but not wasps and hornets.  

The article suggests that these insects help start fermentation in the vineyards by biting the grapes and spreading the common grape yeast, saccharomyces cerevisiae, from berry to berry.  This apparently helps fermentation start in the vineyard, before the grapes even make it to the winery.  S. cerevisiae yeast will impart a sort of “wildness” to the wines that no lab created strain can usually match.  This yeast, found naturally coating each grape, is used for fermentation by wineries who make “natural wines”.  It’s important to realize that in many old world wineries, natural traditional winemaking is still commonly used, and to differentiate that method from the new world style, in which the winemaker uses more modern techniques and products to guide the wines where they want them to go.  As the article discusses Italy, I am ascertaining that it is written about making wine in the old world natural style.  (For the rest of the article, I will refer to the old world winemaking style as “natural” and the new world as “modern”, even though there are examples of both in both regions of the world).


While modern winemakers would want their grapes to come in pristine, hopefully with skins intact and unbroken and not already fermenting, natural winemakers would welcome grapes like this with open arms.  This is because they embrace the hand that Mother Nature dealt them as the natural state of the grapes.  Natural wines are made with as little human manipulation or adjustment as possible, and it is a stylistic choice of the winemaker (although if the winery is in an old world region, such as Italy, it may be ruled by tradition and monitored closely by the government, so not really a choice).  Only the natural yeasts that coat the grapes are used for fermentation, so that has to go off without a hitch, which is rare when using natural yeasts.

Whereas a modern winemaker feels confident only in using lab created yeast strains (which, by the way, are usually cloned from actual natural yeast strains from specific grapes and specific areas of the world famous for great wines), natural winemakers accept the challenge of using only, or mostly, the yeasts from the grapes themselves.  As results can be very unpredictable when fermenting with natural yeast, I have only experimented with it once, personally.  When it does go well, though, it can produce some very interesting and complex aromas and flavors, so sometimes it is worth the risk.  In that case, it may be helpful to have an extra head start from the wasps, as fermentation with natural yeast can take a few days to get going.  Wasps are not needed to start a natural fermentation, as the article seems to imply, however.  The skins need only to be broken, even microscopically, for the yeast to get into the pulp and do its job.  I do agree, as the article says, that different yeast strains not only make a big difference, but can make a difference when added at different times.  For this reason, some labs have created saccharomyces strains that have better predictability with similar results for winemakers to use in the first part of fermentation, and I use them on some of my wines.


The article also goes on to mention that the insects impart other flavors to the wine, but it doesn’t go into detail.  These flavors are usually a little funky, earthy, or horsey.  Most modern winemakers would try to squash these aromas and flavors if they came up, and only want what the fruit and oak themselves add to the mix.  However, some people seem to have a taste for the funkiness, or are at least not bothered by it, and a natural winemaker would just accept it and take a hands-off approach.   

In any case, although I, myself, am inclined more toward the modern style of winemaking, I do prefer organic grape growing.  When the insects and weeds are allowed to go about their business, and the grapes are beautifully perfect orbs, and the bees and wasps are buzzing around, you feel that circle of nature completed when you taste a grape picked right off the vine.  So maybe a thanks is in order to those little wasps and hornets.