Natural Yeast
There are so many myths about sourdough starters worth dispelling, but let's get the biggest one out of the way first: you don't need any special skills or tools to make sourdough starter. It's actually staggeringly easy.
So before you go looking for a starter with a 25-year “lineage”*, let's look at the instructions for making your own:
- Mix together 70g of whole wheat or dark rye flour† and 70g of cool (70ºF/21ºC) water.
- That’s it. (For now, at least.)
Hold on, really?
Yep. There’s a lot more to cover below when it comes to maintaining a starter, but let’s take a brief detour to understand what people mean when they talk about “sourdough starter” and natural yeast.
Yeast (not too different from the kind you can buy in packets at the supermarket) is all around us. In the air, the water we drink, and, crucially, flour. When you create a sourdough starter, you’re cultivating a little bit of yeast that’s found in all those sources—air, water, flour—and keeping it alive in its own little ecosystem.
The only difficult thing about sourdough starters is accommodating for the variances in these different forms of yeast. In other words, factors like where in the world you are, what the climate is like, and even the mineral buildup in your tap water can have an outsized impact on your starter’s needs and flavours.
The key thing here is practice, patience, and experimentation. Try playing with different ratios of flour to water, different kinds of flour, and different temperatures for storing your starter to find what best suits your schedule, location, and climate.
Maintaining Your Starter
After you’ve mixed your starter for the first time, I’m afraid there’s some time to wait before it’s ready to make delicious bread.
You see, when we mixed together the water and flour, we kick-started a chemical (and/or biological) reaction, sending the natural yeast on a journey to devour its way through the available sugars and nutrients. Over time, those nutrients become depleted, and the yeast takes on a sour smell. Once it's passed a certain point, the yeast needs more fresh food (flour and water) to survive the next 8–24 hours.
Repeating this cycle—feeding, waiting 8-24 hours, and feeding again—for a few days will produce a healthy, active culture of yeast ready for baking. Here are the steps, broken down:
- Reserve 30g of the sourdough starter and discard‡ the rest.
- Add to the 30g of starter 70g of whole wheat or dark rye flour and 70g of cool water, mixing it all together.
- Cover the starter with a lid and let rest in a comfortably-temperate location.
- The starter will go on to bubble and even increase up to 3× its original size. After it has peaked (usually 8–24 hours after mixing), repeat the feeding process.
It’ll take a few days for the starter to mature and become ready for baking, but in the mean time, you can bake using commercially-available yeast, as well as learn about and practice some other techniques.