One of the most common questions I get when it comes to the sourdough starter, is how to feed your starter, not only for it to be healthy, but also to optimise & minimise any waste (aka discard).

Quite often, when we start making sourdough bread, we get stuck with a certain way of feeding the starter, whichever that might be. It’s what the recipe says, and we don’t know how to change that. We end up with huge amounts of starter and lots of discard. And sometimes an unhappy starter too. That’s sluggish, doesn’t double in volume, smells acidic too.

With this article, I am hoping to shed some light on how to feed your starter

There are 3 key factors to consider when feeding your starter, so that you end up with the amount of starter you need to make the dough, plus the little extra to carry over to the next feed. You need the carry over to keep the starter going, but too much of it means discard.

🌾The starting point is always the amount of starter you need to prep the dough

Say your recipe calls for 100g starter

🌾You also want the little extra to carryover, to keep the starter going.

20-30g should be sufficient, even as little as 5/10g if you feed your starter every day or every second day. I leave this to you to decide on.

🌾Then you need to consider the feeding ratio you want to use. The feeding ratio gives the fermentation speed and how quickly your starter will be ready to use. The higher the ratio, the longer it will take for the starter to reach its peak.

My go to feeding ratio which gives the perfect balance in flavour (mild, but tangy at the some time), but also fits my schedule is 1:4:4. When feeding the starter in a 1:4:4 feeding ratio, it will be ready to use in something between 6-8h, depending on the room temperature as well, of course.

Now that you got all these, and of course pen & paper, it’s just a quick calculation

Below some guidance on how to come to the quantities of starter, water and flour to use when feeding your starter. You might want to treat this with a pinch of salt, and remember that the quantities are approximate, for reference only. It won’t be the end of the world if you end up with more or less carry over. You might have some discard, but that will be minimum anyways.

Should you want on purpose to have more ‘discard’ to make other recipes, plan with more carryover. And you can use the ‘discard’ while still young, not after it’s been in the fridge for a week, when it became quite acid already, maybe too sour for some recipes.

Feeding ratioAmount of starter
Extra starter
for carryover
Total amount of starter
1:4:480g10g80g +10g =90g90g / (1+4+4) = 90/9 =10g
10g is the amount of starter that needs to be fed
10g starter + (10×4)g water + (10×4) flour = 10 +40 +40 =90g
80g used to make dough with, 10g carried over to the next feed
1:4:4100g20g100g +20g =120g120g / (1+4+4) = 120/9 =14g
14g is the amount of starter that needs to be fed
14g starter + (14×4)g water + (14×4) flour = 14 +56 +56 =125g
1:2:2200g40g200g +40g =240g240g / (1+2+2) = 240/5 = 48g
48g is the amount of starter that needs to be fed
48g starter + (48×2)g water + (48×2) flour = 48 +96 +96 =240g
200g used to make dough with, 40g carried over to the next feed
1:2:2100g25g100g +20g =120g120g / (1+2+2) = 120/5 =25g
25g is the amount of starter that needs to be fed
25g starter + (25×2)g water + (25×2) flour = 25 +50 +50 =125g
100g used to make dough with, 25g carried over to the next feed
How to optimise the starter feeding

Here are some typical quantities and feeding ratios, you might want to use as guidance, without having to go through the entire calculation.

for the dough
for the dough
Feeding ratioQuantities*Time for starter
to peak**
Left in the jar***
500g100g1:4:415g starter
60g water
60g flour
500g100g1:2:225g starter
50g water
50g flour
(2 loaves)
200g1:4:425g starter
100g water
100g flour
(2 loaves)
200g1:2:250g starter
100g water
100g flour
400g80g1:4:410g starter
40g water
40g flour
400g80g1:2:220g starter
40g water
40g flour
How to feed your starter

*Quantities are indicative, there is no significant impact by adding +/-5 g water or flour when feeding your starter

**Time to peak is approximate and it depends on the room temperature. The indicated times are based on a room temperature of 24C / 75F. The higher the temperature, the quicker fermentation will happen. And the other way around

***The starter left it in the jar can be placed back in the fridge without being fed beforehand, especially when you plan on making a dough again in the next couple of days. Should you plan to leave the starter unfed for longer (a week or longer), you may want to give it a feed, before returning it to the fridge. Make sure you let the fermentation start before moving it into the fridge. DO NOT place in the fridge right away

other information which might help you to understand how to feed your starter

🌾CONSIDER USING A SCALE rather than relying on volumetric measurements like cups. Did you know water, flour and the starter weigh differently, so 1/4 cup of each will be different in grams. Not to mention the cups are different in different countries, so you might end up using the wrong measurements.

🌾You don’t have to feed your starter every day if you don’t plan on making bread daily. Instead, you can pop it in the fridge, as the low temperature will slow down its fermentation

🌾Try and stay away from a 1:1:1 (equal parts of starter, water and flour) if you want to maintain a starter that’s not over acidic/ over fermented. With an over fermented starter, the yeast activity might be compromised leading to an under proofed dough, sticky dough, gummy crumb and overall a loaf that’s not rising much.

🌾Remember that a healthy starter fed in a 1:1:1 ratio should be active, double in volume and ready to use in something like 4-5h. Soon after this point, it will start losing volume, become runny and foamy on the surface. Do not leave it for too long before using it.

🌾A 1:4:4 ratio is recommended for a good balance of mildness/acidity. Happy yeast and enough bacterial activity to give the tangy flavour.

🌾Discard is necessary, if you have more starter in the jar than the amount of starter you need to feed. Otherwise you will end up with an unmanageable amount of starter. Not only this, but also the starter will start becoming more and more acidic. The discard should not be fed again.

🌾An over fermented starter will be rather runny, foamy on the surface and loose elasticity and gluey profile.

🌾If you’ve got lots of starter in your jar, give it a reset. Discard most of it, but 20-30g. Move it to a clean jar and feed it. You’ll quickly notice what a difference this makes.

Should you want to learn more about the starter maintenance, you might want to consider purchasing my Sourdough Starter Guide or Joining one of my Online Sourdough Bread making classes