How to Guarantee the Perfect Sourdough Loaf Every Time!

August 16, 2022 | JIM SERPICO

If you are reading this, there is a good chance you love sourdough as much as we do, and want to learn to make the best loaf possible. But what if your loaves aren’t rising the way you’d like?

To answer that question, I’d like to share an excerpt from my recent interview with Tom Cucuzza, the Cleveland-based Sourdough baker obsessed with helping other bakers understand the science behind baking bread. His YouTube channel, The Sourdough Journey, is one of the world’s most popular bread baking channels. Tom’s website is a great source for sourdough bakers; it’s loaded with tons of information and even hosts a sourdough encyclopedia created by Tom.

Tom, thank you so much for joining me! I take it you’re beaming in from the International Institute of the advancement of sourdough science research in Cleveland, Ohio?

Yes, I am, also known as my kitchen!

On behalf of everyone out there, I wanted to thank you. I’ve learned much by watching you, and I appreciate your sharing. So, what was your motivation to share all this with everyone?

I started baking relatively recently. I retired in the summer of 2019 and started baking sourdough in the winter of that year. I found some YouTube videos because that’s how I generally learn best, but I wasn’t finding any good videos that took people step by step through the process. It takes a day and a half to make a sourdough loaf, and they were 8-10 minute videos trying to teach people how to make sourdough, and it just wasn’t working for me.

So I put myself in the shoes of a beginner because I was a beginner at the time, and after I baked 4 or 5 loaves, I got this idea to start recording my bakes so that I could capture all those questions that the beginners have and give them the answers. I wanted to create content for other people, especially home bakers, because so many people attempt sourdough baking and then quit.

I also got involved in some of the sourdough bakers’ Facebook and social media groups. I really enjoyed that because I was doing one-on-one coaching with people, and I quickly developed my own expertise. People would post pictures of their loaves. They would show me a bisection of the loaf and say what happened to my loaf? I got good at reading the crumb of a sourdough loaf. I’ve probably looked at thousands of them and have learned that I can look at the crumb of a loaf and know a lot about how it was baked.

What was the recipe, and what was the bulk fermentation?

How did you shape it?

How did you bake it?

Every loaf tells a story just by looking at that picture of the loaf at the end.

I found that to be interesting and challenging for me, and then I wanted to dig into that and understand the nuance of how you can tell if a loaf is slightly under-proofed or slightly over-proofed. The extreme ends are easy to tell, but I was trying to hone in on the margins and figure out how to give people specific guidance. So I started doing these detailed scientific experiment types of videos.

I love baking and eating, but I get more excitement out of the teaching than I do out of the baking!

Thank you for that! I have heard you talk about strengthening your starter and how the crumb structure may come out depending on your starter. Is that right?

This is probably one of the deepest mysteries of sourdough. You find very little of it in books, this idea of strengthening your starter. There are two components in your starter:
There’s yeast, the good guy, and lactic acid bacteria, which is the bad guy. The yeast is trying to raise the loaf. The lactic acid bacteria create acid or vinegar, which basically tries to deteriorate the loaf, and you can’t separate those things. That’s why it’s common for people to quit making sourdough bread because when you’re making sourdough, you have this epic battle in your starter of the yeast trying to raise the loaf and the lactic acid bacteria trying to destroy it. That’s just what it does as the acidity increases.
When people talk about strengthening their starter, I think it’s really about deacidifying the starter. It’s giving your yeast more of a head start and reducing the population of the lactic acid bacteria. Hence, the yeast has time to rise the loaf before the lactic acid bacteria has time to deteriorate it.

Does that mean the lactic acid builds up so much that it dominates the yeast?

Yes. Lactic acid bacteria will always outrun the yeast by a hundred to one in terms of the number of cells. The yeast goes through kind of a bell curve where it will start creating carbon dioxide, it starts peaking, and then it runs out of gas when you get towards the end of bulk fermentation. The lactic acid bacteria, however, never runs out of gas. It’s just a straight line up to infinity and keeps creating acid. It’s those two curves that you have going on where the yeast is gonna rise and then run out of steam, but the Lactic acid bacteria is just gonna create acid. You have to get that starter set up so the yeast has a fighting chance. You want to have a high yeast population and a low lactic acid bacteria population before you put it in your dough. This will significantly change how your dough bulk ferments and how it bakes and tastes. It’s not so much about the absolute population of the yeast, it’s the relative population. You want more yeast than the lactic acid bacteria. Figuring this out profoundly changed my loaves. When you keep your starter on the countertop, it gets acidic over time. So before I bake, I’ll take my starter and feed it at least three times. As soon as the starter peaks, I discard, do a 1 to 2 feeding, come back again as soon as it peaks, and discard 80%. What you’re doing there is deacidifying it by throwing out the acid and rebalancing the yeast population.

Are there any other ways to de-acidify your starter? 80% is a lot for me to discard.

Yes, that would be a lot for the volume of starter you have! The other way to deacidify your starter is to keep it cool. The discard method is best for people keeping a small jar of starter, but for a larger quantity, just keeping it cool will do the trick. I’ve seen some studies showing that 55 degrees Fahrenheit is the optimal temperature if you keep your starter for a long time without feeding it.

So have you had any major failures or struggles along the way? Can you share some of those?
Yes, sure! One time I decided at the last minute to make a video, and my starter wasn’t really ready to go, but I figured I would try it anyway. I started making the video, and I got into it, and it was just a disaster. The loaves just weren’t rising, and it’s because the starter was super acidic. You could tell that the acidity was deteriorating the loaf before the yeast could raise it. So I played out the whole video and made four disastrous loaves on tape! It really just showed what happens when you have a weak or acidic starter, and it’s a great example, especially for new sourdough bakers out there. It takes a while to get your starter up to full strength when you create one from scratch, and a lot of people will post these pictures and say, what happened to my loaf?I can just tell it’s an immature starter because the yeast population hasn’t grown enough yet, the lactic acid bacteria is going crazy and it creates a real signature style of loaf that looks kind of under-proofed and over-proofed at the same time.

Awesome, well, thank you so much. I enjoyed meeting and talking to you; I’ve learned a lot!

I hope this helped you too! Let us know in the comments below.

You can find more from Tom by subscribing to his  YouTube Channel or by finding him on Facebook.