Ready to learn how to make your own yeast?

Homebrew Recipes: Make Your Own Yeast From Potato Water

I’m not talking about yeast starters and slurries this week. I’m talking about cultivating yeast right in your kitchen, drying and keeping it on hand for the most ethical and delicious of brews. Full disclosure: this is not a necessary part of ethical brewing and it can take a few (or more) tries before you get it right. But once you start doing it and get a good batch you can keep going and use your own yeast any time you’d like. I’ll have a few of these posts arranged by what I’m using to make the yeast. Up first, potatoes!

How To Make Yeast From Scratch

The term “from scratch” is no joke here. I’m going to teach you the most “from scratch” ways to grow your own yeast. Say goodbye to packets and get ready to brag a little. This is going to take your ethical brews to the next level. Keep your sense of adventure about you – wild yeasts can yield interesting flavors. After a while you’ll start using specific ones for specific brews.

What You Need

  • Large glass jar and lid, cleaned and sanitized.
  • Peeled potatoes
  • 1 1/2 cups potato cooking water
  • Cup whole wheat flour
  • Tblspn sugar

How To

I love this method of making yeast because it is a great example of reusing rather than just throwing things out. Thanksgiving is the perfect time to start this batch of yeast. I didn’t put the amount of potatoes because it depends on how many you’re making; but you need 1 1/2 cups of the cooking water no matter what. Don’t use oil or salt in your boil.

  1. Save 1 1/2 cups potato water and pour into your large glass jar once cooled down. If you use a funnel make sure it was sanitized.
  2. Add flour and sugar.
  3. Stir until stiff.
  4. Cover and leave in a warm place overnight.
  5. You should have bubbles in the morning and if you do, it’s ready.

A few things to keep in mind. First, you can use white or whole wheat flour, I just prefer to use whole wheat because I don’t like my food bleached. You can cover using a clean cheesecloth and rubber band if you’re worried about it needing to breathe.

Two Methods For Storing/Feeding

Yeast is a living, breathing organism. For that reason you have to feed it. There are two ways to do this. The fridge version is the more ethical route.

Fridge Method

If you keep your yeast in the fridge you’ll need to feed it every four days. Here’s how:

  1. Remove from fridge.
  2. Remove 1 cup of the starter and dry it out (see below). Replace with 1 cup water, 1 cup flour.

Counter Top

This version must be fed daily using the version above, which results in a great deal of waste which is why I recommend the fridge version.

Drying & Storing Home Made Yeast

Do not compost the 1 cup of starter you remove. Dry it out. Or toss it. Throwing it into your compost can result in all sorts of funk. You don’t want that.

Using the fridge method means slowly increasing the amount of dried yeast you have on hand for baking and brewing.

Spread the 1 cup of yeast on a sanitized cookie sheet. Place in the oven on the lowest possible setting until dry but not cooked. If it cooks the yeast will die. After cooking, crumble into food storage container and store in the fridge or freezer.

One Tip And Then You’re Set

If you use this wet for baking you can use the normal amount of starter. When using the dried version you’ll want to at least double it, but tripling isn’t a bad idea.


    • Hi, Bri, thanks for checking in! You use it as you would yeast. If you use this wet for baking you can use the normal amount of starter. When using the dried version you’ll want to at least double it, but tripling isn’t a bad idea. Let me know if you have other questions 🙂

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