Rule 1: Sourdough Discard Is a Myth
The notion that you need to discard a significant amount of sourdough starter every 12 to 24 hours, or even a couple of times per week, is a myth perpetuated by the internet echo chamber which mostly consists of influencers who are repeating other influencers who themselves learned from other influencers.
There’s even a cottage industry around what to do with this sour trash-goo once it’s no longer suitable for leavening. Oddly enough, many of these same people feed their pets literal meat and don’t fret about how to best bake cat poop into a nice a-pizza pie.
While there’s some evidence that maintaining a large starter helps with the establishment of the initial culture, there’s no reason to do it on an ongoing basis if you aren’t going to bake.
I like to maintain a small starter with the following proportions:
20g whole wheat
13g water
4g starter
Suppose I need 125g of sourdough pre-ferment for a recipe. The night before I want to bake I’ll feed my starter and keep it around 78 °F / 26 °C.
The following morning I’ll feed it again:
20g whole wheat
13g water
20g starter (discarding the rest)
I’ll keep at 78 °F to 82 °F / 26 to 28 °C for ~4 hours.
I’ll follow that up with another quick feeding:
53g flour
53g starter
35g water
I’ll keep it at 78 °F to 82 °F for another ~3.5 hours. Then 125g of that goes into my dough mix, and the small amount that remains will either go into the refrigerator if I’m going to bake again soon, or dry storage if I’m not.
There’s a negligible amount of discard, but I wouldn’t fret either way if I needed to maintain a larger starter. Baking is my cheapest hobby.
Rule 2: Keep Your Starter Warmer Than Room Temperature
Your starter’s hydration controls the makeup of yeasts and bacterias in your culture but the temperature controls the activity rate.
It’s more complicated than this, of course, but this advice is generally true in the 50 °F to 82 °F / 10 °C to 28 °C range. Outside of that range, bacteria tends to outcompete yeast. Within that range, you’ll find that it’s hard to get robust leavening when your starter is maintained below 75 °F / 24 °C.1
If you’ve got a kitchen that’s closer to 70 °F / 21 °C, you’ll still be able to get near-professional quality results as long as you a) maintain a stiff white flour starter and b) have decently large carry-over, such as 1 part starter to 1 part flour and c) feed your starter twice a day.
That said, I bet you’ve got a warmer spot in your home, such as near your water heater, that could get you closer to the Goldilocks zone.
Rule 3: Keep a Stiff Starter, Within Reason
I recommend maintaining a stiff starter at home that’s not so stiff that it can’t be mixed easily with a jar spatula or broken apart quickly by hand during mixing. In practice this means:
60% hydration for white flour starters
65% hydration for whole wheat flour starters
80% hydration for whole rye flour starters
Stiff starters produce a larger amount of Lactobacillus sanfranciscensis at warm temperatures than do liquid ones. L. sanfranciscensis is the bacteria that we generally associate with sourdough bread flavor, a generally pleasurable flavor and aroma that I probably don’t need to describe to you.
On the leavening side of things, there’s a positive correlation between starter stiffness and yeast production due to the propagation of bacteria that are more hospitable to yeast.
Of course, a perfectly good enough reason for maintaining a stiff starter is that it’s a lot less messier than a liquid one.
Rule 4: Prefer Larger Feedings to Smaller Ones
The percentage of starter carried over from one feeding to the next directly influences the stability of your sourdough culture. Large feedings in quick succession at warm temperatures prevent the introduction of new species while ensuring maximum bacteria and yeast cell density. Conversely, a starter fed at irregular intervals with a smaller amount of carryover is more likely to be influenced by outside species, and more likely to have reduced leavening power and flavor potential.
If you like the flavor of your starter increase your carryover.
Rule 5: If You Need To Refrigerate Your Starter, Find a Warmer Spot
Below 41 °F / 5 °C, yeast and sourdough bacteria go dormant and begin to die off in larger numbers. A starter refrigerated at 41 °F will be significantly less sluggish when you go to revive it.
If you can, find the warmest spot in your refrigerator. For most people, this is somewhere on the top shelf, or in one of the doors. To determine if you have spots that are warmer than others, stick a cup of water in the area you want to test overnight and measure the temperature the next morning with an instant read thermometer.
If you want to shell out some money to solve this problem, there’s always the Brød and Taylor Sourdough Home for a very reasonable $99, or wine refrigerators, which are more versatile due to their size but also more expensive.
Rule 6: If You Need To Refrigerate Your Starter for More Than Two Days, Desiccate It Instead
While it’s possible to maintain a reasonably active starter at cooler temperatures, a starter kept cold too often will start to produce off-flavors. This is thought to be due in part to the presence of Lactobacillus plantarum, a bacteria responsible for unpleasantly acetic/bitter sour flavors.
To preserve the flavor profile of your culture during longer periods of inactivity, consider drying it out instead. Here’s what I do with mine:
8g starter
40g flour
Combine and mix until the starter is split into small, dry balls. Cover and refrigerate for a few days, or indefinitely. If you need to keep this at room temperature, it’ll be just fine too.
The night before I want to bake, I’ll sift out the starter and add it to 26g warm water and let it soak for about an hour. Then I’ll add the flour that I sifted out and mix until fully hom*ogenous.
I’ll let this starter sit overnight at warmer temperature (75 - 78 °F / 24 - 26 °C) until the next morning, when I’ll do two quick feedings as described above. Of course, if you don’t want to bake the next day but simply want to resume warm feedings, you would do that here instead.
Rule 7: Preferment As Much of the Whole Grain Portion of Your Recipe As You Can, Within Reason
In recipes that consist mostly of white flour, your bread’s distinctive flavor will mostly come from the whole grain portion.
Given that whole grain flour is not going to contribute to gluten development to the same degree as your white flour, and given that a sourdough pre-ferment represents a weakened gluten structure that you’re introducing to your dough anyway, consider throwing as much whole grain flour into this stage as you can, within reason.
For instance, if you’d normally use 20% levain by flour weight in your recipe, consider using a whole grain sourdough pre-ferment instead of a white flour one. This approach will have the added benefit of softening the tannin in the wheat, thanks to increased production of the enzyme amylase from the starter phase.
Happy baking!
This post may contain affiliate links. If you click an affiliate link and buy a product mentioned, it will directly support Existential Bread.
1
And the same general rule applies to bulk fermentation temperatures.
