- 1
The sugar
Ground corn is cooked, then rye or wheat and a little barley malt are added; the malt's enzymes convert the starch. Many distillers add some spent mash from the last run (sour mash) to keep the acidity steady.
- 2
The ferment
The grain is fermented on the grain, without straining, to about 8–10%.
- 3
The still
Usually in a column ('beer still') followed by a simple pot-like 'doubler' or 'thumper'.
- 4
The wait
Only in new, charred oak containers; summer heat in tall rickhouses pushes the spirit deep into the char, so colour and vanilla come fast. Hot, dry floors can make the strength rise as water evaporates faster than alcohol.
The rules
- Made in the United States from a mash of at least 51% corn
- Distilled to no more than 80% abv (160 proof)
- Into new charred oak containers at no more than 62.5% abv
- Bottled at 40% or more; 'straight' means at least two years
In the glass
Sweet: vanilla, caramel, toasted oak; rye adds spice, wheat softness.