I buy yeast in bulk every few years, freezing it in mason jars. So we still have quite a bit left, but with the yeast supply chain simply unable to cope with exponentially increased demand and logistical disruptions, we began the process of making a sourdough starter. It's been years since I baked sourdough bread, but it is a simple and versatile way to make yeast breads. The neat thing about using your own starter is you are tapping into the microfauna of your particular environment. I made this starter using the directions in the King Arthur Flour's Baker Companion, which is a wonderful book, but I largely adapted the directions since the only listed ingredient I had was water. These things are very forgiving so I'm pretty casual about measuring and sequences.

Ingredients

1. Unbleached, whole wheat flour (white flour is probably OK too but I would definitely recommend unbleached). We purchased 100 lbs of flour a couple weeks from our local mill. Absolute steal, organic flour at a fraction of the cheapest processed flour at the grocery store, plus it is probably chock full of wild year habituated to our climate. About 1 cup.
2. Brown sugar. 1/8 to 1/4 cup.
3. Hot water, about 3/4 cup.

Steps

1. Mix ingredients together well. I didn't knead it using a stand mixer like when I make bread, but I put the kids to work stirring it for a while.
2. Put it in a metal or glass container. Cover with a towel. We use the tea towel that we use to make bread
3. Put in place where it is going to be about 80 degrees F. Traditionally, a stove with a pilot light was the right place. We don't have this so I used my mother's heating pad. She was very reluctant to let me borrow it. I have been pulsing it for a few hours on and then off because, even on the lowest setting, it is pretty warm and I don't want to cook the bread. I am going to keep it off when we are sleeping too.
4. After 24 hours, throw half of it in the compost and add 3/4 to 1 cup more flour and some water. This is feeding the emerging starter.
5. After 2-3 days, tiny bubbles will appear. I am going to cut off the heating pad at that point. Throw out half the starter and add a cup of unbleached white flour and 1/2 cup water. I hate throwing out stuff, but you really need to do this. Compost it or give it to a friend to start her own.
6. Do this twice a day until about a week has passed from step 1. It should be forming small bubbles after feedings, smell yeasty, and taste like sourdough.
7. Try a sourdough bread recipe and see if it works! Remember that sourdough baking is slow compared to instant yeast, so give it a good long first and second rise.

COVID-19 Diary on the homestead
Day 1:on the homestead
Day 2: food security
Day 3: potatoes and resilience
Day 4: sweet potato slips
Day 6: opportunity and risk
Day 7: sustainable food
Day 9: profitable food production
Day 15: small engine repair and goodbyes
Day 21: bullheads and fish oil
Day 33: new brooder, furlough, providence
Day 35: depredation management
Day 43: food bank, potting up, pullets