Can you bake leavened bread without commercial yeast?
Absolutely.
Wild yeast thrives all around us, and you can easily collect some to make your own yeast starter.
One well-known option is the pioneer-style sourdough starter. However, if you want sweeter, milder-tasting bread and other baked goods, try making potato yeast starter.
Keep reading to learn how to cultivate wild yeast using only potatoes and water.
How To Make a Potato Yeast Starter In 6 Easy Steps
Sourdough acquires its typical tangy taste due to acid-producing bacteria in the yeast culture.
This complex, delicious flavor is the hallmark of sourdough bread, but what if you want your baked goods to be less sour?
The following method will give you starter that contains mostly yeast and far less bacteria that produce acetic and lactic acid.
It’s ideal for baking bread, rolls, pancakes, and biscuits with a more neutral flavor.
Caveat: as with all homemade yeast starters, making this one takes time. Commercial baker’s yeast (Saccharomyces cerevisiae) comes from many generations of selective breeding for faster, more efficient fermentation.
Wild yeast ferments sugars more slowly and is less predictable.
Baking with homemade starter requires some pre-planning, since you’ll need to wait a few days before using it.
Follow these steps to unlock the reward of delicious bread with deep, rich flavors, plus the satisfaction of getting dough to rise without commercial yeast.
1. Boil a Potato
Your homemade yeast starter begins with a single potato. Starchy potatoes are the perfect medium for growing yeast.
Peel and boil your potato in 1.5-2 cups of water until it’s completely soft. Use non-chlorinated water, since chlorine could inhibit yeast growth.
Take the potato out of the pot and mash it.
Important: save the cooking water.
2. Place the Potato in a Jar
Take the mashed potato and place it in a clean glass jar. Pour the cooking water over the potato until the jar is almost full. Place the jar on a counter, preferably in a warm area.
Cover the jar with a towel or gauze to keep any debris out, but don’t put a lid on it. You want to invite wild yeast floating in the air to feast on your starchy potato-and-water base.
3. Wait
Now you need a little patience. At first, it may seem like nothing is happening, but in about 24 hours (depending on your kitchen’s temperature), you should notice little bubbles forming on the surface.
That’s the carbon dioxide the yeast produces as it feeds on starch. It’s also what gives bread its delightful spongy texture.
4. Stir the Yeast Culture
Stir the contents of the jar with a clean spoon or put on the lid and shake it to dispense the yeast more evenly (don’t forget to remove the lid later).
Stirring is important because it aerates the culture and gives yeast an advantage over anaerobic bacteria. You might want to do this a few times each day.
5. Wait Some More
Let the jar sit on the counter for another 24 to 48 hours, remembering to stir occasionally.
If all goes right, you should see a lot more bubbles. You may also notice a characteristic yeasty smell – slightly sour and quite pleasant. At this point, your starter is ready for use.
If your starter has a foul or rotten odor, it is best to discard the mixture and start again. Make sure it doesn’t get too, you use a clean jar and it is stirred regularly.
6. Maintain Your Starter
Cover with a loose-fitting lid (so gases can escape) to store any leftover potato yeast starter in the refrigerator and feed it once a week to keep it alive. First, remove half of the starter that remains in the jar.
If you used the potato solids, boil and mash another potato, let it cool, and carefully add it to the starter jar along with its cooking water until the jar is almost full.
If your starter still contains the original mashed potato, you can feed it a tablespoon of flour or sugar once a week and top it with water.
Note: Feeding sugar to the starter will give you quicker fermentation but may also upset the starter’s balance, so proceed with caution.
Let the refrigerated starter sit on the counter and reach room temperature before you use it again. You need the starter to be active when you add it to dough.
FAQs
How To Use Your Potato Yeast Starter
You have two basic ways of using this yeast starter. One, separate the starchy liquid from the mashed potatoes and add it to the dough in place of the water in your bread recipe. You’ll get a soft, moist loaf, perfect for sandwiches.
You can also incorporate the soaked mashed potatoes into the dough together with the liquid. Note that this might make your dough stickier. If kneading by hand becomes too messy, try using a hand or stand mixer.
How Much Time Does Bread Take To Rise With Potato Yeast Starter?
Homemade potato yeast starter works a lot slower compared to packaged dry yeast. With commercial yeast, dough typically rises in 1-3 hours, but when you use homemade starter, you’ll probably need at least 6 hours. I recommend covering your dough with a towel and letting it rise overnight.
How Should You Store Your Potato Yeast Starter?
You can simply freeze your starter if you need to store it for longer than a week without feeding it.
Divide it into portions if you make a larger batch (Ziploc freezer bags work great for this). However, freezing starter as is may diminish its rising power. You need to thaw and patiently feed it to revive it.
Drying your starter is another option for long-term storage. To air dry, spread the starter in a thin layer over parchment paper. Let it sit until no moisture remains and the dried starter separates easily from the paper. You can also use a freeze dryer to speed up the process.
Crumble the dry starter by hand or powder it in a food processor. Store in an airtight jar or bag in a cool, dry place. Rehydrate and feed the starter until it kicks back into action when you’re ready to use it again.
Are There Other Ways To Make Potato Yeast Starter?
Sure. If you look around, you’ll find many other potato yeast starter variations. Some call for adding flour, sugar, or both to the original slurry. Others use dried potato flakes rather than cooked potato.
Every type of yeast starter gives homemade bread a slightly different flavor and texture. You can play around with several recipes until you find the one that works best for you.
What If Your Yeast Culture Smells Bad?
Your starter should have a pleasant yeasty smell, much like rising dough. It may smell a little sour, but any foul odor is a red flag.
Homemade yeast starter may go bad if you don’t stir it enough and anaerobic bacteria overpowers yeast.
Starter can also spoil if left out on the counter too long. If in doubt, it’s best to throw out the yeast culture and try again.
Equipment
- 1 Clean glass jar
- 1 Spoon (for stirring)
- 1 Towel or gauze (to cover the jar)
- 1 Small saucepan (for boiling the potato)
Ingredients
- 1 Potato (peeled)
- 1.5 –2 cups Non-chlorinated water
Instructions
Step 1: Boil the Potato
- Peel and boil the potato in 1.5–2 cups of non-chlorinated water until soft (about 20 minutes).
- Remove the potato, mash it, but save the cooking water—you’ll need it for the starter.
Step 2: Prepare the Jar
- Transfer the mashed potato into a clean glass jar. Pour the reserved cooking water over it until the jar is almost full (leave some space for gas to escape).
- Cover the jar with a towel or gauze to keep debris out, but don’t seal it with a lid—the wild yeast from the air needs to be invited in.
Step 3: Wait for Yeast to Develop
- Place the jar in a warm spot and wait. After about 24 hours, you’ll start seeing small bubbles forming on the surface. These bubbles are the carbon dioxide produced by the yeast as it feeds on the potato starch.
Step 4: Stir the Culture
- Stir the mixture with a clean spoon or shake the jar to redistribute the yeast. Aerating helps yeast thrive over unwanted bacteria. Stir 1–2 times per day.
Step 5: Let It Grow
- Wait for another 24–48 hours, continuing to stir occasionally. By now, your starter should be bubbly and have a pleasant, yeasty smell. If it smells foul or rotten, discard and start over.
Step 6: Maintain Your Starter
- Once your starter is bubbly and smells good, cover it with a loose lid.
- To keep it active, feed it weekly. Discard half of the starter and add either:
- More mashed potato and water from a freshly boiled potato, or
- A tablespoon of flour or sugar to the original mixture.
Notes
- Yeast Development: If you don’t see bubbles after 24 hours, it could be due to cooler temperatures or weak starter. Give it more time or try moving it to a warmer spot.
- Feeding Your Starter: When feeding your starter, make sure to discard half of the mixture before adding new potato or flour. This keeps the culture from becoming too large and keeps it active.
- Potato Type: Starchy potatoes like Russet are ideal, as they provide the right amount of starch for yeast to feed on.
- Long-Term Storage: If freezing or drying your starter, remember that you’ll need to reactivate it with some time and care when you want to use it again.
