What happened to your sourdough starter in 2020?

Paper Bag Sourdough Starter at 10 days. Look at those bubbles!

As we sweep 2020 into the trash bin of history, one of the year’s less serious losses is likely to be ignored: all the sourdough starters that folks initiated as a quarantine activity, then abandoned because they weren’t successful or they felt safe buying store-bought baked goods again.

Getting started with Paper Bag Sourdough Starter

Throughout the pandemic, we’ve shared our sourdough starter with several neighbors and pointed remote readers to the paper bag method which seems to be foolproof. One reader reported that she was using her paper bag starter to stress-bake on Election Day. But we have to believe that some people lacked the patience to go through the steps of generating a starter from flour, water and wild yeast and then nurturing it until ready to use. While others may have made the starter, even baked a few loaves, then forgot about it until they discover a jar full of colorful mold in the back of the refrigerator.

Advice to that second group first: don’t throw it out, no matter how gross it looks. We have often gone for months without using a particular starter (more on that in a moment) and found it if not multicolor, at least well inoculated with a fuzzy layer on top. At this point we go at it with a teaspoon and paper towel. Scoop out the mold, wipe it on the paper towel, then repeat until you expose a layer of clean white. Scoop this out of the jar (taking care to avoid the mold on the side of the jar, or wiping that off with a new paper towel) and refresh the starter. It should come back to life, though it may require a couple of feedings before it is bubbly and ready to put back to work.

Or, if you need to start from scratch, for the first time or not, consider the NC State Wild Sourdough Project. These scientists will take you through the steps of making a starter with wild yeast in the air where you live and then characterizing its activity and aroma and reporting back. You are not going to actually send them a sample of your starter, but they feel the aroma is significant data though I’m not clear on how they measure it. (Here is a follow-on page from the Department of Applied Ecology; they seem to have many projects underway though some may be moribund like the starters themselves.)

The reason starters might differ from one place to another is that wild yeasts will vary according to the climate and what they have to eat in your terroir. Which is why Mom can sell her “233 year old San Francisco starter” on eBay, and over 50,000 people have requested the Alaskan starter from Friends of Carl. And why Gastro Obscura is able to report on a sourdough starter library in Belgium which has collected over 100 starter samples from around the world.

If memory serves, at one time you could order starters from different points of origin on the King Arthur Flour website but today they only have a single starter. Sourdoughs International will ship you localized cultures as will Ed Wood via Amazon. However, eventually any starter is going to be taken over with your own wild yeast that has learned to thrive in your local environment; the small amount of non-local yeast in the imported starter will quickly be overwhelmed.

We did not always believe this, which is why we have faithfully maintained a Cheese Board starter (purloined by buying pizza dough from that iconic Bay Area shop, then refreshing it again and again with water and flour till the salt was strained out), a hybrid starter (combining the starter we used in San Francisco with Saratoga water and local flour after we moved here), and our Hamelman starter (acquired from the master himself, in a baking class).

All were all true to their origins when we acquired them but have become too close to tell apart over time though we still maintain multiple sourdough starters for sentimental reasons (this is why a starter can go unused for months till it becomes moldy). The beasties in the imported products are simply overwhelmed by the yeast in the air you breathe (and carry on your skin).

A final note: it IS a good idea to maintain starters made with different types of flour—rye, einkorn and white and whole wheat are currently in our fridge. Different grains can react to the same yeasts and bacteria (the other component of sourdough activity) in very different ways. And it’s okay to use a rye starter for baking white bread (in fact that’s what Jeffrey Hamelman did for years when a rye starter was all he had) so long as you keep the original starter true to its origins; i.e. always refresh your rye starter with more whole rye flour.