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Ratios for Feeding Sourdough Starter

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Learn all about ratios, what they are and why ratios are important for feeding your sourdough starter in this sourdough starter basics series.


This is actually my third post in this sourdough starter basics series. Ratios are an important concept to understand when it comes to feeding your sourdough starter. If you’re new to sourdough starters, you might want to first read Understanding Sourdough Starters before reading this post on ratios for feeding sourdough starters.

Jar of sourdough starter

The Confusion Behind Sourdough Starters

One of the things that I think contributes towards a big portion of the confusion and uncertainty about where to even start with making a sourdough starter is that everyone seems to have a different recipe, technique or method for making sourdough starter.

And if you’re not familiar with bread baking, let alone sourdough starter bread baking, then this can be quite confusing. However, there are a couple things that ALL sourdough starters have in common.

  1. Ingredients – All sourdough starters begin with whole wheat (or sometimes rye) flour and filtered water.
  2. Ratios – The other thing they have in common is ratios. When you feed your starter, there is a specific amount of flour and water that is added to the starter. This is referred to as “feeding your starter.” Well, that specific amount of flour and water that is fed to your beloved starter is all part of this important ratio.

As I mentioned in my Understanding Sourdough Starters post, the most important thing about starting a sourdough starter is to keep in mind the ratios. So, whether you weigh your ingredients or you measure them out or you just eyeball it, the end result will be the same – wonderful, aromatic sourdough if you keep your ratios consistent. AND what will be key to a thriving starter is the ratio at which it is fed versus the amount of starter.

Ratios for Feeding Sourdough Starter

We’ve already talked about exactly what a sourdough starter is and how it’s alive with naturally occurring wild bacteria and yeast. And these yeast and bacteria need two things to thrive: water and food. The food, of course, is the flour. What happens is that when you add water to the flour, it activates the yeast and bacteria and they start feeding on the starches in the flour. This feeding creates and/or causes carbon gases, acids and alcohol to be released – a process known as fermentation.

Well, to keep your sourdough starter alive, you will need to “feed” it specific amounts of flour and water. This specific amount is known as the ratio. But, how do you know how much food to feed your starter?

I am so glad you asked!

The biggest issue that causes confusion, hesitation, fear and obstacles to people learning how to make their own starter and maintain it has to do with there being so many different methods. How do you know which method is right? Who do you listen to?

Again, I’m glad you asked!

The 1:1:1 Ratio

There appears to be many different methods for creating sourdough starters. But, don’t let that confuse you. What may seem like different methods are really just people using different ratios.

So, let’s take a look at the minimum feeding or the 1:1:1 ratio. What this means is that however much starter you keep by weight, you will want to feed your starter equal amounts of flour and water by weight.

For example, let’s pretend you have 25 grams of your starter that you have saved and want to continue feeding. For a 1:1:1 feeding ratio you would feed the 25 grams of starter with 25 grams of water and 25 grams of flour. Once you add the 25 grams of water and 25 grams of flour to the 25 grams of starter, you will now have 75 grams total starter after your feeding. Make sense?

Think of it as one part starter, one part water, plus one part flour (or 1:1:1). Just remember to keep all parts equal by weight. This is the ratio that I recommend for starting and feeding your starter until it is well established (after the 10-14 day initial time frame).

Other Ratios

While 1:1:1 ratio is the minimum feeding ratio used for making a sourdough starter, there are other common ratios used. Some people use a 1:2:2, 1:3:3 or 1:4:4 or even higher ratio. No matter what ratio they use, the numbers all represent the amount of starter by weight that is being fed by the weight of water and flour feedings.

Again, let’s say you have 25 grams of starter. For the 1:2:2 feeding you would give your starter 50 grams of water (2×25=50) and 50 grams of flour, resulting in 125 grams (25+50+50=125) of total starter after the feeding.

So, with a 1:3:3 ratio you would start by weighing your starter. For the purpose of this tutorial, let’s say it weighs 25 grams. So, you would add 3×25 or 75 grams of both water and flour to the 25 grams of starter, leaving you with 175 grams of total starter after the feeding. Because 25+75+75=175.

The 1:3:3 Ratio

When I am starting a new starter, I use the 1:1:1 ratio for the first two weeks (10-14 days). After that, I begin using a 1:3:3 ratio. Here’s what this would look like:

Day 1: Start with 30 grams of flour and 30 grams of water, which will result in a 60 grams starter. Mix thoroughly, affix lid loosely, let sit in warm place 24 hours.

Day 2: Discard half my starter so that I have 30 grams of starter. Add 30 grams of water and 30 grams of flour. Stir well. Again affix lid loosely and sit in warm place for 24 hours. This will result in 90 grams of starter (30+30+30=90).

Days 3-14: Repeat Day 2.

NOTE: When I say “discard” I literally mean for you to throw that portion of your starter away. You can use it in composting, but you definitely do not want to pour the starter down your drain.

After day 14, I’m ready to begin the regular maintenance of my starter. Let’s assume I want to keep it out at room temperature because I plan on baking bread or pancakes every single day.

Day 15: Discard half my starter (45 grams) into another glass jar or bowl (because I plan to use this discard). My starter now weighs 45 grams (90/2=45). So, I’ll add 135 grams (45×3) of water to my starter and 135 grams of flour, leaving me with a 315 grams starter.

Day 16-???: Discard all but 45 grams of starter. Add 135 grams of water and 135 grams of flour to my starter. Again, I’m maintaining a 315 grams starter. I can discard more or less, depending on what I need for my recipe. I just must always keep this ratio in mind. Whatever my starter weighs, I’ll feed it three times that weight with water and flour.

jar of sourdough starter

How Much Starter to Keep and Feed

When I am making a new starter, I like to start with the 1:1:1 ratio. So, say I start with 30 grams of flour by weight (which is approximately 1 ounce), to that 30 grams of flour, I will add 30 grams of water. Definitely a 1:1 ratio. And after I mix the two together, I’m left with a 60 gram starter.

On day #2 of my feeding, I can either add 60 grams of flour and 60 grams of water to my 60 grams of starter OR I can discard part of the starter and feed it accordingly. Say for example that I discard half of my starter, that should leave me approximately 30 grams of starter. To my 30 grams of starter, I will then add 30 grams of water and 30 grams of flour.

I will repeat this process every day for 10-14 days or however long it takes for my starter to mature and be ready to leaven bread. How do I know when my starter is ready? Keep reading and I’ll explain that in a moment.

Back to my starter. What if I decide to keep the entire starter and maintain a 1:1:1 ratio? Well, my 2nd day of feeding would look like this. My starter weighs 60 grams, so I add 60 grams of water and 60 grams of flour. I now have a fed starter that weighs 180 grams. On day 3, I will add 180 grams of water and 180 grams of flour to my 180 grams starter, for a fed starter of 540 grams.

So, by this you can see at the end of 10 days I’m gonna have a LOT of starter – most of which I will discard. It’s really not necessary to have that much starter. To keep my starter more manageable and to keep from wasting so much flour, I use the discard method.

Why Discard Starter?

This brings up a good question. Why do we discard a portion of our starter? The most basic reason is so that we keep our starter at a manageable size. By keeping the size of our starter on the smaller side, we are also wasting less flour.

If we didn’t discard some of the starter, can you just imagine how much starter we would end up with? Plus, remember that the starter is a living thing that needs to be fed equal amounts of water and flour. That could potentially be an enormous amount of both.

Also, keep in mind that most of the discarding is done during the initial starter creation stage. Once you have a healthy starter that is capable of leavening bread, you’ll more than likely use the discarded portion in recipes. Even if you don’t want or need to bake a loaf of bread, you can use sourdough starter discard (after it’s mature) to make pancakes, crackers or even biscuits.

jar of sourdough starter

Sourdough Starter Basics Series

This is the third post in my sourdough starter basics series. You’ll find the other posts in this bread making series here:

Helpful Resources

Some of my favorite sourdough resources that I have actually used and learned from are listed below.

I also have a Sourdough Bread Playlist on my YouTube Channel.

I hope this sourdough starter basics lesson on understanding sourdough starters has proven helpful to you. Be sure to check out my sourdough starter recipe, garlic parmesan sourdough starter recipe and check back often as this is just the second blog post in my sourdough basics series.

Til next time…

Pam Baker from The Birch Cottage

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