The base spirit of a gin refers to the distillate to which botanicals were added. It’s helpful to think about the base spirit as a vodka-like spirit that the distiller used as a starting point— a blank canvas upon which the gin was designed.
But choice of base alone doesn’t mean that you’ll be able to taste it. Depending on choices the distiller makes, such as how many times the base is distilled, or to what strength it is distilled to— there might be no character at all coming from the base spirit.
Even the term “wheat” itself isn’t a single ingredient. When a distiller makes a wheat base it can be from any number of cultivars.
Most wheat is categorized by the hardness of its kernel (soft or hard)
And further broken down by the color of its kernel (red and white) and which season it is grown in.
Some common wheat types include “hard red winter,” “soft red winter,” “hard red spring,” etc.
Bakers value the different varieties based on protein content. But since protein doesn’t survive the distillation process, distillers often select the cultivar for their wheat base based on a combination of factors like local availability and desired mouthfeel.
Soft Red Winter wheat is particularly common among distillers. Sipping a vodka distilled from that wheat base and you might notice a residual creamy, gentle vanilla flavor.
Historically speaking, wheat was not a common base for gin up until the 20th century. Wheat as a crop needs to be alternated with other crops, and because it is such a useful grain for baking, there was often very little good-quality grain on the market for distillers. Advances in crop technology and modern agriculture have reduced wheat scarcity and now distillers can choose a wheat base if their heart-so-desires.