What are the "folds" and "formulas"?

Vanilla extract is made by soaking vanilla beans in 70-100 proof alcohol for 4-12 months. How many vanilla beans you use depends on a few things. The formulas are guidelines for how much to use.

The FDA Formula is a legal formula created by the government for commercial vanilla producers using Grade B vanilla beans. They say that if you use less than 1 gram of vanilla beans for 10ml of alcohol you can't legally call it vanilla extract. The Co-Op considers it a good starting point.

The Co-Op Formula is based on the FDA rule but is 20% stronger. It was made to make conversion simpler for home cooks and Co-op members and is based on 1oz. of beans to 1 cup of alcohol. It also accounts for the fact that the Grade A beans the Co-Op uses are a little heavier, and also makes a richer extract a little more quickly.

The Budget Formula is what you can use if you're trying to get the most extract possible from your Grade A vanilla beans. This formula is 5% more vanilla beans than the FDA formula to account for using the heavier Grade A vanilla beans the Co-Op uses.

Single Fold is just regular strength vanilla. When baking recipes call for 1 teaspoon of vanilla extract, they mean single fold. Single fold is what's sold commercially.

Double and Triple Fold just mean double or triple strength vanilla extract. The only reason to use these is for baking recipes. It allows you to get double or triple the vanilla flavor with less liquid. Or, some people are just crazy about vanilla flavor and like the strongest extract possible.