San Francisco Sourdough Conclusion

Toast
doughooker on 18 Jan 2025 at 22:36

After much trial and error and little success, I think I know why I've had so much difficulty in replicating the old-school San Francisco sourdough breads of yesteryear, made by Larraburu, Parisian, Colombo, etc.

Those breads were very, very sour, with a strong lactic-acid note. It is very difficult for the home baker to replicate the strong sourness of those breads. I've come close to the old-school flavor and aroma by way overproofing dough, but this overproofed dough is unworkable. It is nearly liquid in consistency and does not result in a viable risen loaf.

What we know about the old-school sourdough process is that a stiff sponge of about 50% hydration was maintained. This sponge was refreshed every eight hours (three times in a 24-hour period) and was kept refrigerated. I think this accounts for the strong sourness of the bread.

The bakeries of yesteryear were baking 24 hours per day, seven days per week. They could thus consume the sponge as quickly as it was refreshed. That is to say, sponge refreshment kept pace with the demand for sponge in the baking of bread. The home baker is likely not baking 24/7 and is likely unable to refresh a sponge every eight hours without generating a surplus of starter which might only be discarded.

I believe this is why the very sour, old-school sourdough is difficult for the home baker to replicate. The 24/7 baking regimen of the erstwhile bakeries and the requisite sponge refreshment schedule was the main contributing factor to the strong sourness of those breads.

When I was making it, it had a growth of kahm yeast at the beginning. With time I managed to get it under control and it went away. However, if left unfed (even in the fridge) for about a week the kahm yeast would be back. Then again, with some TLC and a few feeds it went away once again. However the resulting bread was very sour. Not nice at all! I think the flavour should come from the grain itself with the fermentation enhancing it. I've since made a new starter and it's far nicer. So if San Francisco breads were as sour as you describe then it's not something i'd be after. 

Profile picture for user alcophile

alcophile on 19 Jan 2025 at 11:18

That SFSD flavor certainly is elusive. I've occasionally tried experiments to vary parameters to produce a more sour loaf to no avail. I have produced sour rye loaves, but then rye doesn't break down the same way that wheat gluten does. 

I'm still trying to find a way to reliably achieve that flavor with batch parameters instead of a cold proof (too small fridge). Most of the "extra-sour" SFSD recipes I see use that cold proof to increase sourness. We know that method wasn't used in the old Larraburu process.

We do know that the sponge was refrigerated between refreshments.

Still, what home baker is going to rebuild a sponge every 8 hours and consume all of the sponge they build?

 

doughooker,

If you're interested in a deep dive,  Brod & Taylor provides a write-up of the process which can be found on their website at:

Part I — How to Make Sourdough More (or Less) Sour

https://brodandtaylor.com/blogs/recipes/make-sourdough-more-sour

 

Part II — How to Make Sourdough More (or Less) Sour

https://brodandtaylor.com/blogs/recipes/make-sourdough-more-or-less-sour-part-2

 

I've used the information and methodology to make some very sour sourdough bread.

Tony

 

I've tried the B&T instructions for making more sour bread and it didn't seem all that sour. I also tried Teresa Greenway's Northwest Sourdough method (bought the course) with the same result.

I've also explored the original Larraburu process as outlined by Kline and Sugihara and Galal, et al.; and a method using acid whey from a US patent. None so far have yielded the SFSD that tastes sour enough.

I'll keep trying, though!

Times 3

I've tried Teresa Greenway's method as well with unsatisfactory results.

 

My best results have come from refreshing a starter, let it peak and start to decline, then refrigerate for a day or two - that kicks up the tang a bit. 

I was simply musing as to why we get strong sourness from bakery-baked bread and not from home-baked bread.

One problem I've had at home with the sponge-and-dough method is that the sponge overproofs and turns liquid.

Have you ever tried any inactivated sourdough extract, like this one:

 

 

I wonder if a high dose of it or similar plus a process designed to enhance sourness might give you the flavour you want?

 

Lance

In the next town over from me, I just found a tiny bakery, and they use what they called "dehydrated sourdough yeast" from Germany. It might be the same thing, perhaps.  The two loaves of theirs I tried were not sour at all, though very good.

The reason for using the product is that the baker has struggled with food reactions for years and found that all commercial yeast made in the US, at least, includes various additives including some alcohol sugars (I think they are) like sorbitan monostearate. She thinks it is one of many ingredients that give her problems so she won't use commercial US yeast, but she told me that they had too many problems keeping a starter going. The German product doesn't include such ingredients, according to her.

TomP

I saw this post a couple months back about "Instant Sourdough" and decided to give the product a try a try:

https://www.thefreshloaf.com/node/74777/newfangled-sourdough

I first used it in King Arthur's Country Loaf (https://www.kingarthurbaking.com/recipes/country-loaf-recipe). We could not detect any sour flavor in the bread, but it did stay fresh much longer than I would have expected for a nearly all white, lean loaf.

In the event that the whole wheat was masking the sourness, I tried another package of this yeast in KAB's Easiest Loaf (https://www.kingarthurbaking.com/recipes/the-easiest-loaf-of-bread-youll-ever-bake-recipe). I substituted 1 g of active barley malt for the sugar in the recipe. Again, no sourness detected, but the loaf stayed fresh for many days.

Conclusion: Not good for sour flavor, but excellent for staling prevention.

I wonder if they are using Sekowa Backferment? https://luba.de/en/sekowa-baking-ferment-250-g-tin/

I've tried it in the past and it works very well and the bread produced is mild in flavour, but good. The only downside for me is that it takes you out of the normal sourdough loop and you can't just pick a random sourdough recipe and use it - you are kind of on your own.

 

Lance

Red Star yeast is part of Lesaffre Group in the US. It's most likely packaging some of the commercial Lesaffre inactive sourdough for the consumer. I've been curious about the Sekowa but I don't think it's available in the US.