There aren’t a ton of restrictions on the source materials you can use to make vodka. Distillers can use pretty much anything that can be broken down into fermentable sugar as the source for vodka, as long as it’s distilled to near neutrality. While the sky may be the limit for source materials, vodka is most commonly made from corn (Crystal Head), wheat (Absolut), grapes, rye (Belvedere), potatoes (Karlsson’s), and the ubiquitous “neutral grain” which can be almost any grain or mix of grains (including even soy). Whey isn’t a very common vodka source, although like any fermentable sugar it can be transformed into alcohol with the right kind of yeast. VDKA 6100 Vodka may not be the first vodka to use whey (that distinction goes to Vermont Spirit’s White Vodka), but it is the first real major international play for whey in the vodka category.