The Importance of Good Distillers Yeast For distillers, particularly the ever-growing ranks of craft distillers have focused their research on “flavour derived” yeasts, for distilled spirits. These yeasts are targeted to produce specific types of spirits—and flavours. For those accustomed to thinking that the raw material of a spirit (like grains, fruits, and molasses) provides the flavour baseline, it’s eye-opening to realize that yeasts are involved in flavour as well: A more “neutral” yeast can be selected to make vodka, for example; for whiskey, a producer can select yeasts designed to produce a more (or less) aromatic spirit.
Some producers will test-drive many yeast strains (or combinations of different strains) to find the flavour profile they want. Fermentation can bring to whiskey: fruity, floral, green grass, soapy, and sulfuric notes. All of these can be driven by yeast choices along with changes in temperature, pH levels, oxygen, and nutrient levels. In addition, fermentation can be soured intentionally with competing bacteria for additional flavors.
Alcoholic Fermentation The yeast fungus splits a glucose molecule, producing two ethanol molecules and two carbon dioxide molecules per ring, as well as heat energy. In addition, the reaction and its following by-reactions produce aromatic substances (esters) that give whiskey its great variety of taste.
In Scotland usually, two different dry yeasts are used: baker’s and brewer’s yeast. Baker’s yeast makes the fermentation process start quickly. At the same time, the wash is acidified. Brewer’s yeast works better in an acidic environment and achieves its maximum performance later. It makes sure that the wash has a high alcohol content. American whiskey producers attach great importance to the fruity esters of special yeasts. That’s why each bourbon has its own yeast(s).
Note: The Fermentis Distillers yeasts are repacked to 100gm and 50gm, contact us if you want a full 500gm pack.