Starter Feeding Methods | How To Reduce Sourdough Discard  

A mature sourdough starter requires frequent refreshments to remain active. This can lead to it needing to be fed two or three times a day in warm climates, which is a lot of effort for most home bakers. It also leads to a lot of discard waste. But don’t worry, I have a selection of methods that solve this! Before we get into them, though, I need to explain something in sourdough baking called the “Motherdough”.

The motherdough method

A motherdough is a starter that is a stored mature starter. In this case, it will be left in the fridge. The cool temperature means it ferments much slower and doesn’t require regular feedings. A motherdough can be left for one or two weeks before needing to be refreshed. Turning your active starter into a motherdough reduces the amount of starter you’ll need to discard.

For each batch of bread, the desired amount of starter is removed and refreshed with exact measurements of flour and water. The result is the exact amount of starter needed for the recipe. The mother dough can remain relatively small to further reduce discard waste. It can then be fed more than once at the same ratio to build up the required amount. It’s a great way to save on waste and is handy for home bakers who bake once or twice a week. 

Refresh the mother dough feeding method

Alternatively, the required amount of starter can be removed from chilled mother dough without any refreshments. Afterwards, the mother dough is refreshed and goes back into the refrigerator. The minor issue with this method is that the starter may peak and then collapse before you want to use it, making it less effective as a levain. Also, as the mother dough is always in the fridge, it becomes less active over time. It will require a couple of refreshments at room temperature every month (or so) to bring it back to maturity. Many bakers find the drop in activity negligible, so it can be a sensible choice to store and feed your starter.

Using the fridge to slow down refreshments

If you bake more often but not twice a day, you can reduce the number of refreshments by taking your starter in and out of the fridge. This method can also be used when removing a piece of starter from the motherdough or to refresh the motherdough as a whole.

Zero-waste refreshment method

If you make sourdough bread once a week, the zero-waste “scrapings” method works really well. It’s derived from how European bakers have produced sourdough for years. The wooden trough used to knead the dough is left uncleaned between bakes. A week later (or whenever), they add water to it, bringing the yeast back to life for use in another dough.

To replicate this method at home, remove the desired amount of starter from your mother dough. Then pop the starter container in the fridge without refreshing it. The day before you make bread, remove it from the fridge and start building the starter up with two feedings around 12 hours apart. Use a ratio of 1:2:2 of starter, flour and water in the first refreshment. For the second refreshment, use your normal feeding ratio, which, if you are following my starter recipe, is 1:10:8. You’re unlikely to need to discard any of the starter during these refreshments, making the method zero-waste. The remnants (or scrapings) can be left for 5-7 days fine without being fed without a problem. Here’s an idea of how it works:

1st refreshment

• 10 grams starter (remnants)
• 20 grams water
• 20 grams flour
• = 50 grams starter -however, you’ll lose some weight as it ferments so it will be around 40 grams

2nd refreshment

• 40 grams starter
• 240 grams water
• 400 grams flour
• = 680 grams active starter

Note: You will lose some starter weight due to evaporation, so instead of 680 grams, you’ll get around 650 grams to use. Retain another 10 grams in your container to put back in the fridge and repeat the storage method.

Can I make sourdough bread with a cold starter?

A cold starter can be used to make sourdough bread. It will be cooler. Therefore the water temperature of the dough should be adjusted using a desired dough temperature formula. Providing the temperature is acknowledged, using a starter from the fridge is no problem. What might happen is the starter doesn’t rise when it is time to come out of the fridge. To remedy this, I’ll leave it out for an hour or two before using it to get things going.