What kind of yeast is used to make wine

Winemaking was difficult before the advent of temperature control. Coaxing barely ripe, sour grapes to ferment in cold, northerly cellars or attempting to control runaway fermentation in large, bubbling tanks was not uncommon.

Now we can manage every aspect of fermentation. The nitrogen content of grapes can be measured, and their acidity can be adjusted. Cellars or fermentation tanks can be warmed to kick-start the yeasts, then cooled to keep fermentation steady and flavors fresh. Fermentation can also be stopped to create sweet wines with natural residual sugar. Left to its own devices, pressed grape juice or crushed grapes will start to ferment due to natural yeasts present on grape skins and in the winery.

This is known as natural, wild or spontaneous fermentation. In natural fermentation, various strains of yeast will get to work, but most will die off quickly. Eventually, a strain of alcohol-tolerant Saccharomyces cerevisiae takes over to finish the job, but spontaneous ferments are unpredictable and can be hard to get going.

Thank You! We've received your email address, and soon you will start getting exclusive offers and news from Wine Enthusiast. To help matters along, winemakers often started a small, so-called pied de cuve with a bucket of ripe, healthy grapes a few days before harvest.

They used this live culture to inoculate new ferments and avoid spoilage. This used to be a very real risk. In the s, scientists began to isolate and multiply certain yeast strains. Fresh grape musts or crushed grapes began being inoculated with rehydrated, freeze-dried granules of a dominant strain.

It kills all other yeast strains and sees a clean fermentation completed within one to two weeks. Barring gross negligence, the risk of stuck fermentation is eliminated. Hundreds of cultured yeasts are available commercially, and many have been cultivated from specific regions and wineries to preserve their local character. They guarantee predictable, clean and safe results. While most cultured yeasts are neutral, imparting little flavor on to the wine, some have additional properties.

So-called aroma yeasts favor the synthesis of certain thiol compounds responsible for tropical fruit notes in grape varieties like Sauvignon Blanc. Some convert sugar into alcohol more or less effectively, while others work more efficiently at certain temperatures. To make a good, clean wine with spontaneous fermentation is only possible with healthy, high-quality grapes.

Those depleted of nutrients, carrying residues from antifungal spray or containing otherwise moldy or rotten fruit may not start to ferment. If they do, the finished product may not be palatable.

A spontaneous ferment, even with the finest grapes, still requires lavish care. Hans Oliver Spanier, of Weingut Battenfeld-Spanier in Rheinhessen, Germany, farms his vines biodynamically and has never used cultured yeasts. Undesirable yeast strains are a risk, too, [as] is volatile acidity. Spanier likens wild ferments to cheese made from unpasteurized milk. He says that spontaneous ferments are best suited to smaller productions, where such care is possible.

But we achieve commensurate prices for our wines. By the same token, I have had the most amazing wines made with cultured yeasts. Years ago wine makers would place their fruit in a crock, or container, leave it open to the air and let what yeast was floating around start the fermentation. There are some obvious draw backs to this, but many people made wine this way up to the s and s. Some people continue to make wine this way.

We do not recommend making wine in this fashion for many reasons, but here are just a few for you:. What do you do? Simple, you mix everything together just as Grandpa's recipe says, but you add your own yeast to the juice. Hint: In addition to adding yeast, make sure you use a lid and an Airlock on your fermenter to prevent nasty things like bugs or bacteria from ruining your wine.

Find our full line of Wine Making equipment here. Pairing Yeasts With Fruit Montrachet is a very good dry yeast to use for fruit wine. We do not recommend making wine in this fashion for many reasons, but here are just a few for you: The wine does not always ferment.

This is a very common issue when relying on airborne yeast to ferment anything. The fruit goes bad before the wine starts to ferment. No CO2 to protect the fruit will lead to a strong chance that the fruit will rot before you even start the wine making process.

Left to their own devices, these wild yeasts will ferment the sugars in crushed fruit into alcohol. But outside of laboratory experiments, K. By the time we got to 10 percent sugar, every time, all the vineyard yeasts were gone. The wild yeast species turn sugar into ethanol, but once the concentration of ethanol in their environment reaches higher than 5 percent, it kills them; strains of S.

At Hermann J. Wiemer Vineyard in the Finger Lakes region of New York, the winemaker Fred Merwarth has transitioned, one wine at a time, from commercial to indigenous yeasts, over the course of a dozen years. It actually creates a lot more work, because [with indigenous yeast] every vintage is totally different—the length of the fermentation is a lot harder to predict. And the microflora were consistent within each block from one vintage to the next.

Because of its ubiquity, and its importance to wine and quite a few other industries, S. The single species of yeast has evolved—with and without deliberate breeding help—into thousands of strains with varying characteristics.