Do you know how to make your own yeast? If you’ve been prepping for any length of time, you undoubtedly have several pounds of wheat berries stored away. You may also have experimented with making your own wonderfully delicious bread, because you know cooking from scratch is a critical survival skill. The downside of long-term prepping and bread making is keeping active yeast on hand. One solution is to learn how to make yeast from scratch.
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What is Yeast?
Yeast is a tiny living organism that belongs to the fungus family. It’s commonly used in baking and making bread. When you mix it with sugar and warm water, it becomes active and starts to grow. As it grows, it produces carbon dioxide gas, which makes dough rise and become fluffy when you’re baking bread.
So basically, yeast is a tiny living thing that helps make bread soft and fluffy by producing gas.
Two Forms for Baking
Both wet and dry versions can be used in baking. Wet yeast, though, because 2/3 of it is moisture, doesn’t have the shelf life that we preppers typically want.
How long do store-bought varieties last?
The average “best by” date on commercial varieties is 2 years. Once opened, it must be kept cool and dry. In a refrigerator, it can remain good for up to 4 months; in the freezer for 6 months.
Occasionally there are people who have had success with older yeast. (I’m one!) The general rule of thumb, though, is that store-bought is for the short term.
How to test old yeast to see if it’s still active
If you have store-bought yeast stored longer than the above-mentioned time frames, follow this simple test to proof it and see if it’s still active. I was amazed when a large, 2-pound package I purchased more than 10 years ago was still active. So glad I hadn’t thrown it out!
How to Proof Yeast
- Dissolve 1 teaspoon of sugar in 1/2 C warm water from the tap. Between 110°F-115°F is most effective. The only way to really be sure about the temperature is to use a thermometer. When in doubt, the water from your faucet should be warm but NOT hot to the touch.
- Stir in your dry yeast, either one 1/4 oz. packet (7g) or 2 1/4 teaspoons of granulated yeast. Most people say that the yeast should be brought to room temperature first, but I have always had good luck when using it straight from the freezer.
- It only takes three or four minutes for the yeast to “wake up” and start to rise. After ten minutes, the surface of your yeast-water mixture should have a foamy top. If so, then congratulations! You have active yeast! It should be used immediately.
- Most recipes take into account the liquid needed to proof yeast. If yours does not, deduct 1/2 cup of liquid from your recipe if you proof the yeast with this method.
A good way to tell if your yeast has risen sufficiently is to use a 1 C measuring cup. If the yeast foam reaches the top, you’re good to go. If your leavening agent has an insufficient rise, it will not be any good for baking. Best to throw out the entire container.
Learn How to Make Yeast From Scratch
If you can’t get to a grocery store for Fleischman’s, what’s the alternative? Try growing your own yeast!
Here are a few methods that should fit most needs and skill levels. Depending on the availability of the items listed below, choose one that best fits you, your region, and your personal stockpile.
Once you have your jar of starter, your next question will be, now what? In this post I show you how I use this starter to bake a loaf of bread.
From Raisin / Fruit Yeast
- Clean Glass jar. (24oz. or larger) Sterilize in hot water and allow it to dry.
- Water. Clean, filtered, or bottled is good. Tap water can be used, depending on your local conditions. Warning: Too much chlorine in your water, or water that is too basic, can kill the yeast.
- Raisins or other fruit. Most fruits have traces of yeast on their skins. Note that you may not get as good of a result with fruit that has been washed and waxed.
- Place three to four tablespoons of raisins in your jar. Adding a few tablespoons of honey or sugar will facilitate the fermentation process.
- Fill the jar ¾ full with water. Place the lid on the jar lightly. Do NOT tighten the lid – you will want to allow some air to escape.
- Place jar at constant room temperature. Do not allow the jar to get cold. This will kill off the yeast and stop the process.
- Stir at least once a day for three to four days.
- When bubbles form on the top, and you smell a wine-like fermentation, you have yeast. The raisins, or fruit, should be floating.
- Before adding additional flour and water to feed your new yeast, remove the raisins and discard.
From Grain/ Sourdough Starter
Yeast is already present on grain. All you need to do is to cultivate it in a manner similar to the above instructions. Here is a basic recipe for a sourdough starter.
- 1 1/4 C unbleached all-purpose flour or milled wheat berries
- 1 C clean warm water
- 1 sterile jar with cheesecloth or lid
- Mix the flour and warm water, and keep it at room temperature.
- After several days, the mixture will start to bubble and will begin to rise.
- At this point, you’ll begin to feed your yeast and help it grow and develop into a true “starter”.
- Keep your starter in the refrigerator when not in use. Use as you would any sourdough starter.
The starch in potatoes makes it another prime candidate for yeast production.
- 1 unpeeled medium-sized potato
- 4 C warm water
- 1 tsp salt
- 1 tsp sugar
- 1-quart jar
- Rinse your potato to remove dirt, but don’t scrub it too much.
- Cut it into pieces to facilitate cooking, then boil until cooked through.
- Drain, and save the water.
- Mash the potato and add sugar and salt.
- Allow mixture to cool until it is at room temperature.
- Add water to the potato mash until the whole mixture equals 1 quart.
- Cover and let sit in a warm place and allow it to ferment for several days.
- Pour the mixture through a sieve to filter out the potato sediment. Save the liquid starter and begin to feed it following the instructions below.
Feeding the Starter
Once you have created your own yeast, you must “feed” it regularly. This means adding 1 cup flour and 1 cup of water to the mix so that it can keep growing. You will need to feed the starter daily if it is at room temperature or weekly if it is in the fridge.
It usually takes another 5-6 days of feeding your starter before it’s ready to use in baking. Use these instructions to begin to bake bread.
If you don’t bake bread that day, you will also need to toss out one cup of the starter after feeding so that the ratios stay the same. This is an important step and can be a great motivator to bake regularly so that none of your hard work goes to waste!
Yeast starters are one thing you will not want to throw in the compost pile, as the bacteria can grow out of control and give you a very unpleasant result. Here are some things you CAN throw in your compost for some extra fertilizing goodness!
I have my yeast, now what?
No matter which method you choose, making your own yeast is a skill that dates back thousands of years. Begin practicing using your DIY yeast to make bread and post your results. Feel free to add your own ideas and advice in the comment section below.
NOTE: If you landed on this page looking for information about nutritional yeast, we’ve got you covered. Read more about using deactivated yeast in your prepping pantry here.
Do you know how to make yeast from scratch? Share your experience in the comments!
This article was originally published in 2011. It has been updated and revised.