I am trying to make a sourdough sponge as described here:
I keep some starter in the fridge which has long since liquefied due to proteolysis. There is no way around this liquefication. I mix 50% refrigerated starter, 100% flour and water into a stiff dough and proof them at exactly 86 F.
Eight hours later I no longer have a stiff sponge but a bowl of liquefied goo. Is this normal? Am I doing something wrong? At least I know the starter is active if it's degrading my sponge, or so I assume.
I cannot rebuild my "mother sponge" every 8 hours or I would have a ridiculous amount of discard. One can eat only so many "starter pancakes".
If I mix the sponge and refrigerate it, the microbial growth will slow way down. This is a microbiological fact. My sponge will have less of the lactic-acid and yeast microbes because their reproductive rate is much lower.
After 8 hours of proofing time, I made up my dough using this goop (sponge) per the formula linked to above. I let the dough (not sponge) proof for 9 hours at 86 F. Interestingly, the dough did not turn to goo as the sponge did. It was a somewhat firm dough ball and easy to slash.
Of note is that the sponge did not contain salt, whereas the dough did. I added about 1/2 tsp of salt to the dough which was made with 150 g of flour.
In all cases I'm using KA unbleached AP flour.
Closer examination of the S.F. sourdough process reveals that the sponges were proofed at 80° F rather than 86° F.
I'm a little unclear on what you really did since your description seems to differ from the linked recipe. When my refrigerated starter gets soupy, I usually refresh it several times before I use it for making bread, and I think you should consider doing that too. My starter has 100% hydration, and can last usually 3 days or so before getting soupy. The linked recipe uses the starter to make up a stiff (low-hydration) sponge so I assume the original starter would be the same. A low hydration starter should last longer before needing refresh. There should be no need to "rebuild" it every 8 hours, and doing so would probably make the starter less acidic.
I have tried making a loaf of bread using soupy starter, and it worked all right, with a reasonably normal dough. I had to use less water than usual to get a normal dough consistency, as if about 2/3 of the soupy starter acted like water instead of the actual 1/2 value. Of course there's a difference between a starter that's been soupy for days and one that's been soupy for weeks, and we don't know about yours.
The recipe calls for developing the starter at 80 deg. F but you said you used 86 deg. F. That would cause development to take place much faster. If I left my 100% hydration out at room temperature overnight, it would probably be fairly thin the next morning. A stiff starter would hold up better but at a temperature of 80 deg. F it might not hold out for much longer (I haven't tried this so it's just a guess).
The longer you refrigerate your starter the more sour it will get, although this doesn't always come out in the finished bread. It is common to refrigerate dough during or after the bulk fermentation phase and to have the final bread turn out to be more sour than expected. So don't sell refrigerating the dough or loaf short.
I was clear in describing my process:
What is unclear to you?
This is how half a dozen bay area sourdough bakeries did it. If you need to see it in black and white it would take me a lot of searching to find an authoritative citation. Remember, they were baking around the clock.
That took less searching than I thought. It's in USDA patent #3,826,850:
https://patentimages.storage.googleapis.com/cd/3b/0d/f2eb7c00201294/US3826850.pdf
Yes, and as you wrote they are doing it day in and day out. They are going to need more starter often since they will be baking lots of loaves, so they need a regular, reliable schedule that produces manageable amounts of starter.
You and I are not in that position. We also don't have their starter, which will have evolved to thrive under those conditions. And we may not have their flour, either. However, the only alternative is not to keep your own starter in the refrigerator for extended periods without feeding and then to use it as is. What works for me is to keep it in the refrigerator, feed it when it starts to thin out or apparently become inactive, and then use that refreshed starter directly or to build a working levain for use in the bread.
You say
That's not low hydration or stiff, that's what unclear.
My standard starter is 100% hydration and no, that's not stiff at all. I was suggesting that you use a stiffer one, if you don't already. Stiffer ones take longer to ferment.
Read the whole thing:
100% water would not make a stiff dough.
Exactly, and yet you say it's stiff.
Kline/Sugihara/McCready's formula: 100% starter, 100% high-gluten flour, 48-52% water, 7-8 hours at 80F
doughooker's formula: 50% starter, 100% all purpose flour, unspecified water (100%?), 8 hours at 86F
It appears that you have five different factors that will cause a different result than you intended.
First, the condition of your starter. I very much doubt that the researchers relied on a starter that was so overripe that it was proteolytic.
Second, the researchers used double the quantity of starter, which would have led to more rapid fermentation in the sponge and would also lower likelihood of proteolysis in the sponge.
Third, the researchers used high-gluten flour, not AP flour. Even allowing that KA AP has more protein than most AP flours, it is much lower in protein than a high-gluten flour. This makes it less tolerant of proteolytic activity during fermentation.
Fourth, I don't know how to parse the "100% flour and water" that you mention. Should I read that as 100% flour and 100% water? If so, that would produce a markedly softer sponge than one built with 48-52% water.
Fifth, the 86F temperature for your fermentation would have slightly favored bacterial growth over yeast while the researchers' 80F temperature for fermentation would have slightly favored yeast growth over bacterial growth.
Your likelihood of having similar results as the researchers did would be greatly helped if you began with a robust starter and then followed their protocol precisely.
I'm going to go out on a limb and make a statement that I'm in no position to back up: I don't think that any of us as home bakers are going to be able to duplicate the product of a commercial bakery, even if we knew exactly how things were done at the bakery. Our environments are different, our ingredients are different, our tools are different, and our processes are different. If, in spite of all of those differences, we produce a bread that is reminiscent of the bread that the bakery produces, we can count it as a win.
Paul
The contrary can be true, too. At home we can sometimes do things that would be impractical in a commercial bakery, even an "artisanal" one.
That may well be true to the extent that it's impractical for a home baker to continuously maintain a starter by refreshing it 3x per day in perpetuity. This would result in a surfeit of starter.
The crux of my OP remains: is it normal for a stiff sponge to turn to goo after 8 hours at 86° F?
here is, repetition.
The documented process is actually describing something cyclical and to reproduce it one must replicate the cycle too.
One pass using a different type of starter will give different results. It takes time (repetition) to end up with something that performs similarly.
While feeding every 8 hours is impractical, the fridge does present a perfectly workable solution.
Try this:
1 part previous sponge
1 part flour (hi gluten)
50% water
Hold at 80F for 8 hours and then transfer to the fridge. The next day (or even 2/3 days later) repeat the process using this as the previous sponge.
After several days (passes) the degradation factor will change considerably becoming more solid.
Hi Michael -
What will 3 days in the fridge achieve?
It would mainly be for your scheduling convenience, though the eventual flavor would probably be better (and possibly more sour). It *might* also help accustom the starter to the new schedule.
Hi Chris,
Sorry I wasn't very clear, I was trying to give a range of time, i.e., 1-3 days in the fridge. Meaning that I think it will be good for that time, where not much will happen. The microbes will drift into stasis but will still be ready to go again when taken out and refreshed.
As Tom (tpassin) commented, this time in the fridge was exactly for the reason of convenience.
By doing this, it allows you to refresh the sponge several times over several days. After remaking the sponge several times, it will not degrade as much and be in far better shape when used to make the bread dough formulation.
Michael