A few people I know have not been able to find yeast in the store recently. There is no knead to despair if you want to bake bread, but have no yeast. There are other options. Here is Ashley Adamant of Practical Self Reliance, writing Potato Yeast Starter for Baking Bread
No yeast at home? Try culturing your own wild yeast on potatoes! All you need is one medium-sized potato, a bit of water and smidge of patience.
Believe it or not, commercial yeast has only been available in well-stocked grocery stores for the past 100 years or so. Leavened bread, however, has been baked for millennia.
It’s convenient to be sure, but yeast packets are not the only way to leaven bread.
In times past, bakers cultured their own wild yeast for raising bread. Sourdough is one version, and it’s a community of yeast and lactic acid bacteria (like in yogurt) that give the bread a characteristic sour taste.
But what if you don’t like sourdough (or don’t have the patience to maintain one)?
There are literally dozens of ways to culture a wild yeast starter, using everything from raisins to beer to wild apples.
This simple method cultures wild yeast on boiled potatoes and was originally used by vodka distillers making high-quality potato vodka. The idea is to just culture yeast, without encouraging the lactic acid bacteria that are part of sourdough.
DIY Potato Yeast Starter for Bread
Potatoes are high in starch, which is ideal for culturing yeast. They also contain plenty of micro-nutrients, making them a better yeast starter than sugar alone.
There are a number of different potato yeast starter recipes circulating on the internet at the moment, ever since yeast disappeared from store shelves this spring.
Guess what…they all work.
Some add sugar, others add a bit of flour and some are just a mashed potato and the starchy water used to boil it.
Mash it all together, and then leave it open on the counter for 2-3 days. Yeast floating by in the air will settle on your starchy yeast trap, and quickly go to work reproducing.
The simplest method, and the one originally used for vodka production, was just a single potato.
Peel the potato and place it in a pot of water. Bring the water to a boil, and then simmer for 35-45 minutes, until the potato is completely soft. Test it with a fork to ensure that it’s cooked and soft all the way to the center.
Pour the cooking water into a container, and allow it to cool. Meanwhile, thoroughly mash the potato.
Place the mashed potato into a one-quart mason jar, and then pour the starchy potato cooking water in to fill the jar. If you’re a bit short on cooking water, just add clean, chlorine-free drinking water.
Set the jar on the counter (open or covered with a towel), and wait.
In about 24 – 36 hours, you should see the first tiny bubble on the surface. (Look closely at the potato layer below, and you’ll see tiny bubbles forming there too.)
Cap up the jar, give it a vigorous shake to distribute the yeast and then open it up and leave the jar on the counter again.
In another 24 to 36 hours the jar should really be bubbling. At this point, you can bake your first loaf of bread…