Home Sourdough Starter Guide

Sourdough Starter Guide

sourdough starter jar

Let me first say, I am by no means an expert. However, the one thing I am is persistent. You will probably fail at this a few times. I have failed MANY times. But like many things in life, enjoy the process, learn from these mistakes, and keep going – it’s worth it! This page is an organization of all my research and geared towards someone who basically knows very little about sourdough or making a starter.

The good news here is the cost of failure for a sourdough starter is relatively low. And occasionally, you can reflect on your mistakes while eating a fantastic tasting, somewhat flat, slice of bread.

There are essentially 3 broad activities phases your starter goes through:
1. Building
2. Maintaining (aka “feeding”)
3. Preparing to Bake (aka “Making a Levain”)

The building steps are something you do once to get it started. The Maintain steps are where you spend most of your time keeping your starter alive and healthy. Lastly, the Preparing to Bake steps are performed just before you want to bake.

Some Pro Tips

  • Ensure you have a calibrated scale that measures in grams
  • Measure the tare weight of your jars (write down on piece of paper or jar itself)
  • Do not use city/tap water – it has chlorine. Use filtered/distilled water
  • Get yourself a Silicone jar scraper (or two) for mixing and scraping jar sides
  • Always add water first, mix that with any previous starter first, then add dry ingredients
  • Don’t let too much dried starter form on the sides of the jar. A few days is fine, but swap to a new jar as needed

Lifecycle of a Starter

During a the Maintain phase, every time you add flour and water to your starter you are giving the existing yeast cultures more food to consume and multiply. During this process, yeast/bacteria consume that food, multiply exponentially and carbon dioxide is produced as a byproduct. This will all be visually present in your starter as it grows in height and develops lots of air bubbles. However, during this process, there are also some negative byproducts. The biggest one is acidity, which begins to build up and eventually ‘smothers’ the yeast, preventing them from eating/multiplying and further. At this point, you will notice the starter’s height stall out and eventually begin to lower back to its original height. It is during this stall period, max height, with a nice dome at the top (BEFORE it begins to drop), which is referred to as the “peak” (more on that later). Once a starter has fallen back to its original height, it still contains a lot of yeast/bacterial, but also contains a lot of acidity which we don’t want (more on this in the next section). For more information on the lifecycle of the starter – highly recommend this website.


One last note before we begin. Ratios. You’ll see mention of ratios through this page. They are very important. There are a lot of resources that can go deeper on theories and results, but here’s the quick and dirty. A ratio (e.g. 1:1:1) is the relationship to quantities of EXISTING STARTER : TOTAL NEW FLOUR : WATER. How much existing starter you decide to keep and the ratio you use will dictate how much new flour and water you add.

For example, 50g of existing starter with a ratio of 1:1:1 might be 50g existing starter + 50g flour + 50g water. That same ratio might also look like 20g existing starter + 20g flour + 20g water if you kept less existing starter. Using a ratio of 1:5:5 would be 20g existing starter + 100g flour + 100g water.

Why different ratios?
Again, there are a lot more resources out there on this topic, but here’s again, the quick and dirty: We don’t need to keep that much existing starter maintain a healthy starter…something like 20-30g should be plenty. However, we can adjust the amount of existing starter and the ratio (and also the temperature) to control several things:

Total quantity of starter: obviously adjusting the amount of existing starter and the ratio can dramatically alter the quantity of active “peak” starter we have. This can be 100% personal based on how much starter you want to keep around, starter ‘waste’ you are willing to live with, how much your recipes call for (although we’ll talk about making a Levain too), etc.

Lifecycle Duration: another consideration for different ratios is time. If you feed your existing starter 1:1:1, you are giving it an equal amount of food to its size. If you feed it 1:5:5, you are giving the existing starter 5x the amount of food and the cycle time will take much longer to complete. Because the cycle duration is longer, this also means the window during peak time is greater. A 1:1:1 ratio will cycle quickly you really need to know how your starter behaves to find this window. Whereas, a 1:5:5 will have a peak window of several hours making it easier if your schedule isn’t as flexible.

Make a ratio decision based on this can be 100% personal based on your baking preference. I have found 1:3:3 (30g, 90g, 90g) takes about 12 hours in my kitchen, which works perfectly for 2x feeding morning/night.
Side note: regardless of the size of your existing starter, all 1:3:3 ratio starters should take about the same amount of time.

Reduce Acidity: also, recall, a lot of residual acidity can exist after a starter lifecycle completes. We don’t want acidity – it will suffocate the yeast during the proofing phase and you can be left with weak dough that doesn’t rise. To reduce this acidity, we can do two things: 1) reduce the amount of existing starter we keep (20-30g is good) and also 2) use a higher ratio… something like 1:3:3 or 1:5:5 (or even 1:10:10) which will result in a higher quantity of active/peak starter essentially diluting any acidity that came over.



During this phase you are capturing initial yeast and bacteria from the air in your kitchen. It’s very important to be patient during this phase. Don’t set yourself up with expectations, follow the plan and you’ll be good!

Day 1
1. Add 100g Whole Grain Rye flour to jar
2. Add 125g filtered water 75-80°F to jar
3. Mix until dry parts incorporated
4. Lightly cover jar and place in warm area (70-80°F) for 24hrs

Day 2
You may/may not see any fermentation activity. No worries.
1. Add 75g of previous day’s starter into a new jar (discard the rest)
2. Add 50g Whole Grain Rye flour to jar
3. Add 50g Bread flour to jar
4. Add 115g filtered water 75-80ºF to jar
5. Mix until dry parts incorporated
6. Lightly cover jar and place in warm area (70-80°F) for 24hrs

Day 3
You may/may not see any fermentation activity. No worries.
1. Repeat Day 2 steps into a new jar

Day 4
You should be seeing fermentation activity by now. If not, diligently check you are measuring quantities and temperatures accurately. We will begin 2x/day feedings now.
Morning (~7:00am)
1. Repeat Day 2 steps into a new jar (let rest 12 hours)
Evening (~7:00pm)
1. Repeat Day 2 steps into same jar (let rest 12 hours)
pro tip: add water first and use water to clear jar with scraper

Day 5 and Day 6
1. Repeat Day 4 (2x / day) in same jar

Congrats you have a baby starter! I call this a “baby” because up to this point we have been making a starter with a 1:1:1 ratio. Recall that 1:1:1 starter may run the risk of carrying over acidity – happened to me! So as we transition to the Maintaining phase, I’d highly recommend experimenting with higher ratios like 1:3:3 and 1:5:5 to see how that impacts total quantity and cycle duration for your needs


Maintaining (aka “feeding”)

Most experts agree that feeding 2x / day is ideal. As you might imagine by now, this is aligned to the expected cycle duration of 12hrs for a ratio of 1:3:3. However, it is technically possible to feed a starter 1:1:1 once every other day, just to keep it on life support, but you definitely run the risk of acidity and low yeast population. If you do this, I would highly recommend slowly working it back up to 1:3:3 or 1:5:5 a few days before you will need it for baking.

Ongoing Feeding (1:3:3)
1. Keep 20g existing starter in same jar (discard the rest)
2. Add 60g of filtered 80°F water to jar and mix with existing starter
3. Add 30g of Whole Wheat Flour to jar
4. Add 60g of Bread Flour to jar
5. Mix thoroughly (~1 to 2 minutes until dry parts are incorporated)
6.Lightly cover jar and place in warm area (70-80°F) for 12hrs

Longer Storage
For longer periods in between baking, or going on vacation, many people store their starter in the fridge. When doing this, the cold temperature will massively slow the yeast activity. What otherwise might be a 12hr cycle, could be 5-10 days! Just keep in mind, when you take the starter out of the fridge, it will benefit from several days of 2x/day feedings to get it back to a health/active state again.

Example Fridge Method:
Saturday morning: Feed Starter. Let sit out for 1-2 hours to get healthy start to fermentation. Put in fridge
Thursday morning: Take starter out of fridge. Put in warm location (should perk up with activity by afternoon)
Thursday evening: Feeding
Friday morning/evening: Feedings
Saturday morning: Feed Starter. Let sit out for 1-2 hours to get start to fermentation. Put in fridge
Saturday morning: Make Levain (and dough according to recipe). Bake or cold retard overnight, bake on Sunday


Preparing to Bake (aka “Making a Levain”)

A Levain is nothing more than a “child” or second clone of your starter. When retaining some existing starter, you will also retain some to make a second starter. This second starter, aka “Levain” is what is used in the actual loaf, so you can keep your starter going and don’t have to start over with the Building phase.

Building the Levain should be spelled out by your recipe. However, it may only list a total quantity of Levain… let’s say 150g. In this case, use your ratio to work backwards. 1:1:1 can be an ok ratio here because you are going to use the Levain right at peak and don’t have to worry about acidity…and 1:1:1 will be the fastest method too. 1:1:1 is simply to calculate because you can divide total Levain quantity by 3. So, 50g existing starter + 50g flour + 50g water. 1:2:2 is also common. In this case, there are 5 total units (1+2+2), so you would divide by 5 (e.g. 30g existing + 60g flour + 60g water). You could certainly use a 1:3:3 or higher Levain ratio but this may not be desired because it will take approximately 12 hours to cycle.


Well that’s it! Just kidding – it’s just the beginning! Honestly, the best way to learn is to do, make mistakes, and analyze your results.

I wish you the best of luck on your sourdough journey! Drop me a comment or tag me on social media @erickraus and send me a pic of your starter or loaf!

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