Sourdough Starter
By Joe Bender
There are few things as satisfying as a freshly baked loaf of bread. With so many of us spending so much time indoors social distancing these days, it’s a perfect time to give it a try, or to try out a new technique if you’re an experienced baker. Whether you want to take your baking to the next level or need an alternative to commercial yeast — or you just want to try some fermentation at home — using a sourdough starter is a huge step forward. When you use a starter in place of commercial yeast (and sometimes along with it) to leaven the bread, this beneficial microbial community can add new worlds of flavor and nutrition to your baking.
A sourdough starter is made up of the wild yeasts naturally found on the grain, in the air and on your skin. By “catching” these wild yeasts, giving them a medium in which to grow, and feeding them regularly for a few days, you create an environment where the healthy, beneficial yeasts prosper and harmful microorganisms (like some bacteria, molds, etc.) can’t take hold. Once your culture is established, it will feed you for years to come. When you put it to work in bread or other baked goods, it ferments the grain, bringing out worlds of flavor and improving the available nutrition from your ingredients in the process. You’ll also be participating in a millennia-old tradition of humans and yeasts working together and feeding each other. It’s a great way to feel closer to the food we eat and the world we share.
I put off trying my hand at sourdough for years, thinking it would be too hard to start and maintain a healthy starter. Two years ago my ambition overcame my hesitation, and I gave it a shot, only to find that it’s much easier than I thought. It only took about a week from mixing up my first batter to baking my first loaf, and maintaining it has been easier than I expected too.
Starting the starter
To catch a starter, you begin with a batter that’s approximately equal parts by weight flour and water, let the wild yeasts begin to ferment and then feed it on a schedule for a few days until it rises and falls regularly with your pattern of feedings.
This “training” creates the right conditions for the beneficial yeasts that you want to form a robust community and drive out other microorganisms that you don’t. Over the course of a week you’ll go from an anarchic first fermentation to predictable rising and falling after feeding, to making your first leaven and baking your first sourdough. You’ll feed the culture daily for the first three days, then morning and evening for a few days more.
A note about equipment: You don’t really need any specialized equipment to catch a starter or bake great sourdough, just a jar, some flour and water. However, one thing that really helps — and that will be invaluable when you get to the bread-making stage — is a kitchen scale. Bread recipes typically use weight (ounces or grams) instead of volume (cups) for measures because the ingredients — and even different flours — have different densities. Using weight also allows you to express the ratio of the different ingredients as a percentage of the total weight of the batch, which makes them easy to compare and replicate. If you have a kitchen scale, it’s easy to learn how to measure your ingredients by weight. If you don’t have one though, it’s not a problem, you can use conversion tables or an online converter to measure by volume. This free converter lets you specify what you’re converting (e.g. flour, water, salt, etc.) so that you get an accurate result.
Ingredients:
100g or 3/4 cup flour: rye or whole wheat is best, but really any flour or combination of flours will work
125g or 1/2 cup water: tepid or warm to the touch
Two glass jars, large enough to hold your starter with plenty of room to spare
Day one
If you’re using a scale, place your first jar on the scale and tare. Add the flour and water to the jar and mix until all the flour is incorporated and you have a thick batter. The water should be room temperature or a bit warmer, between 65 and 80 degrees. Drip a drop or two of the water on the inside of your wrist. The temperature should feel neutral or warm, not cold or hot. Fermentation is a temperature-dependent process, and generally the warmer it is the faster the fermentation goes. If the room you’re working in is cool, your fermentation will be slower, and you can use warmer water to speed things along.
For the flour, you can use any combination of all purpose flour, white bread flour, whole wheat or rye. Many guides suggest that you make up a batch of half-and-half white and whole wheat to feed your starter. We’re fortunate to have access to some amazing flours at the Co-Op; we stock several bulk flours from Farmer Ground. Grown and milled in New York State, they’re among the best flours you can buy in the area.
Scrape down the sides of your jar; a silicone spatula is good for this. Cover your jar loosely with the lid — just don’t screw it on — or a cloth. Place the jar in a bowl in case it overflows, put it in a warm place and leave it overnight. That’s it for day one!
A note about flours: Among the Farmer Ground flours at the Co-op, in your bread adventures you may want to play with all-purpose flour, white bread flour, whole wheat and rye. The main differences between wheat flours are the protein content and how much of the germ (the outer husk of the grain) is removed before milling. Whole wheat flours include the whole wheat germ, while in white flours some of the germ has been removed before milling. Wheat flours typically have a protein concentration between 10 and 14%, and higher-protein flours are described as “stronger” than lower-protein varieties. Farmer Ground’s pastry flour is 8% protein, the all-purpose flour is 10%, and the whole wheat bread flour is 12%. The highest-protein flours you’ll typically see are called 00 flours (for chewy doughs and long fermentation), and they’re in the 13-14%range.
In general, higher-protein flours will want longer fermentation times and will produce a chewier, more structured crumb. Lower-protein flours are more tender and used for things like pastries in addition to softer breads. All-purpose flour, living up to its name, is in the middle so it can be used for either. Each kind of flour has its own characteristics and will behave differently in your breads; rye flour for example is low in protein and has a characteristic sweet flavor, so breads that use a high percentage of rye flour tend to have a more dense and even crumb. My favorite combination is 20% rye flour, 20% whole wheat and 60% white bread flour, which gives a rich, hearty flavor and a structured crumb.
Days two and three
In the morning, your starter may or may not be bubbly, showing signs of fermentation. This initial surge in fermentation can be substantial and make the starter overflow, which is why we put the jar in a bowl. However, this initial surge isn’t what we’re looking for in a mature starter and will subside as we culture the beneficial yeasts that we’ll use to bake.
So on day two, transfer a couple of spoonfuls (about 75g) of the mixture to your second, clean jar, then mix in 100g flour or flour mixture and 125g water. Mix it up and let it sit again for 24 hours. Throw out or compost the remainder and clean the first jar for the next day.
On day three you may start to see signs of increased fermentation, or not yet. Don’t worry, it’ll come. Repeat the feeding process, again transferring 75g of the mixture to the clean jar and adding 100g flour and 125g water. Stir it up, scrape down the sides, and leave overnight again.
Days four to six (or seven)
On day four and the next few days, you’ll refresh your starter approximately every 12 hours, morning and night. The timing doesn’t have to be exact, and after this period you can feed less frequently, daily if you’re baking every day, or weekly (or even less frequently) if you’re baking less and keeping your starter in the fridge. Once your starter is well established, you can also use smaller quantities of flour and water. Nowadays I typically use 50g flour and 50g water.
So on the morning of day four, transfer and feed your starter, and then do the same 12 hours later. By now you should start to see increasing fermentation activity. Over the first few hours after feeding, your starter will start to show bubbles and increase in volume, and then start to slump down toward the next feeding time. Continue the process twice a day for the next few days.
By day six or seven, you should see your starter rising and falling predictably with each feeding. Once it’s showing strong, regular fermentation, you can make a leaven and bake your first batch of bread if you’re ready, or you can slow down to daily feedings until you’re ready to bake. If your starter isn’t rising and falling regularly yet, don’t worry, just keep feeding it and the fermentation activity should increase until you have a strong starter. The timing depends on a host of environmental factors, the wild yeasts you started with, the temperature, etc. Be patient and you’ll get there.
Once you’re ready to bake, here’s a great recipe for baking your first loaf of sourdough bread from Maurizio Leo of The Perfect Loaf.
Long-term care
Finally, now that you’ve raised and trained your very own sourdough starter, you want to take good care of your culture. When I first caught my starter, I would keep it out at room temperature and feed it every day. That gets exhausting, and it feels like you wind up using and composting a lot of flour. What I found over time is that the easiest method is to keep the starter in the fridge and feed it much less frequently.
At the moment I’m making about one batch of bread a week — I make three loaves and pop two in the freezer until I’m ready to eat them. Two days before I want to bake, I take my starter out of the fridge, stir it up (it separates a bit when left in the fridge for a week), discard all but a tablespoon, feed it with 50g flour and 50g water, and let it revive for 12 hours or overnight. When it’s well-risen and bubbly, I use half to make my leaven and bake my bread. The other half I feed again with 50g flour and 50g water, cover it loosely and pop it back in the fridge for a week until I’m ready to bake again. When I’m not baking regularly, I just keep it in the fridge and feed it every two to three weeks. If you forget to feed it for longer though, don’t worry, starters are pretty resilient. Just mix it up with some fresh flour and water and it will most likely bounce right back.
Happy baking!