How much yeast do you put in a 5 gallon mash?

How Much Yeast for a 5-Gallon Mash?

When making a 5-gallon mash, getting the yeast right is crucial for a solid fermentation. Too little, and you risk a slow or incomplete ferment; too much, and you might introduce off-flavors. The sweet spot? Two packets of active dry yeast, which typically equals about 14 grams. If you're using bulk yeast, a level tablespoon should do the trick.

But don’t just dump it in. For best results, create a simple starter. Mix the yeast with warm sugar water—about 1 cup of water and a teaspoon of sugar—swirl it gently to combine, and let it sit for around 20 minutes. You’ll know it’s working when the mixture doubles in volume, showing that the yeast is alive, active, and ready to go.

Once the starter is foamy and lively, stir it into your cooled mash. Don’t forget to aerate the mixture right after. Oxygen at this stage gives the yeast the boost it needs to multiply and kick off fermentation efficiently. Skipping aeration can lead to sluggish starts or stuck ferments—something every distiller wants to avoid.

This method, tried and tested by home distillers for years, ensures a strong, healthy fermentation. Whether you're making corn whiskey, sugar wash, or a specialty spirit, starting right with the right amount of properly activated yeast sets the foundation for a clean, robust final product. It’s a small step that makes a big difference.