Gluten breakdown during bulk
This has been a recurring problem with several starters. My starter lives in the fridge. I practice a no discard maintenance - I keep only the scrapings each bake, add ~2-3 TBS water and enough flour to make a thick paste and put it straight back in the fridge with no room temperature time. It is very active and even at fridge temperatures with a very small inoculation doubles in a couple of days and at room temperature in ~6 hours. I bake ~ every 10 days and refresh it twice before use.
Yesterday
I was making Hamelman's 5 grain sourdough according to the recipe. I made a levain with the rye flour which was fresh ground and left it overnight. The first and second stretch and folds showed nice gluten development. On the 3rd the dough slackened and by the end of bulk there was evident gluten breakdown and the dough was sticky and maybe slightly slimey. I did manage to shape it using extra flour and it rose well and baked into a nice loaf with no off flavours.
This starter is ~1 year old. it's maintained with Morbread bead flour and an occasional boost of rye if it seems less active. When this has happened with other starters I have tried extra feedings - which has never solved the problem so I've presumed they have somehow developed a protease enzyme and discarded them. The starters never smell 'off' or have 'hooch' or any discoloration and the problem isonly evident when I come to bake.
Does anyone have a solution or explanation?
I believe your protease hypothesis to be correct. I ran into this many years ago myself, and much good information was offered here on TFL. You can review it here in my blog if you wish. One of the very earliest comments by Debra Wink is the direct reference. My solution for the involved starter was as Debra recommended: "feed it through". About 20 days of twice daily feedings with carefully controlled timing did the job, and the theology issue resolved.
The other thing I did was to abandon the effort to "convert" my long-standing whole grain starter to a patent flour starter. Now, when a "white" starter is required, I do this step in the very first elaboration with as minimal an inoculation as possible, and ignore the tiny component of whole grain in the resulting loaves.
I don't want to revisit this in my kitchen again. Ever!
Best of luck with it
OldWoodenSpoon
Thank you for the reply and links. My experience was exactly like David Snyder's - I got gluten development with the first S&F and it improved with the second but at the end of bulk it was breaking down.
I stuck it in the fridge to try to firm it up a bit and managed to get a rough shape with some flour and no pre-shape and then proofed the loaves in the fridge in the hope of slowing down the enzyme or whatever. They actually rose pretty well and I even got some oven spring -though they spread out a bit and the resulting bread wasn't bad.
I've been baking bread for over 30 years and this is the second time this has happened - again with a very active starter. I didn't have much luck with repeat feedings - though I admit I didn't persist for 20 days. I think I can get a new starter going in less time than that.
I tried to post pictures but they are IMG format and were rejected.
Patsy
If you're doing something and it continues to fail then try a different approach.
First thing i'd do is switch your starter maintenance method. Try giving it a few feeds and allowing it to mature at room temperature (give the yeasts a chance to multiply) before using in the dough. After you have taken off what you need return excess mature starter to the fridge till next time.
If this solves the problem then it's the starter maintenance that's the issue.
I used to do something similar but got far better results when maturing my starter in warmer temps. Yeasts need warmth and a starter with a good yeast population is a healthy starter. At some point in your starter maintenance time at room temperature is important. I find keeping your starter always cold will make a poor starter. Sounds like your starter is never given some TLC which for a starter is food and warmth.
I actually do most of that. My starter is maintained as a softish dough probably 60% hydration for ~ 10 days in the fridge and is actively rising and sweet smelling, so I don't think it is starving. It is fed liberally twice and left at room temperature for 24 hours before use.
De Muzio asserts that protease activity increases dramatically in liquid starters and during autolysis and that this is a benefit making stiff doughs more extensible in less time. I use a stiff starter, a one hour autolyse and 30 minute S&F's so it seems unlikely that the protease is being given excess time to develop.
I can think of a few things I do that might encourage excess proteolysis -
1. the overnight levain which is usually done with freshly ground flour - in yesterday's bread, rye.
2. I dislike sour bread and use more starter than many bakers to speed fermentation. In this case it was ~ 4oz with the 8oz of rye in the levain which was left overnight. But again I have been doing this for years.
3. the fairly high percentage of whole meal flour, much of it fresh ground. I believe the last time this happened it was with Hamelman's 5 grain sourdough, too. But this is my favourite bread and I make it regularly without problems.
My starter was really active and looked and smelled great before this bake, so I'm not sure what to look for before I try to bake with it again.
Thank you all for your input and suggestions.
Patsy
If the gluten is breaking down - the starter is no longer good. Enjoy!
Hi, Patsy.
As I read your message, I couldn't help but wonder if the issue you're experiencing is due to the characteristics of fresh-ground flour. Fresh-ground flours are notorious for fermenting quickly, and simultaneously developing their gluten structures at a much slower rate than aged flours. Rye typically has more protein than wheat flour, but less of that protein is of the types which form the gluten strands that create the structure for bread. It has no gliadin, but instead has secalin, which does a very poor job of forming the gluten strands that assist the structure of bread.
My first thought is perhaps make your levain using one of the other flours in your recipe, and add the fresh-ground rye in during the dough mixing phase. While it may seem counterintuitive, the fermentation speed of the fresh flour could be causing your dough to run out of gas during the bulk fermentation, and even gentle handling after that point will inevitably have a degassing effect.
If you try this, please let us know your results!
Randem (aka Simplicity is Important)
Thank you, that is something I've considered. I did notice that the overnight levain, made with 100% fresh rye had collapsed by morning. I'm giving up on this starter - it looked and smelled fine when it came out of the fridge and responded normally to two feedings, so I have no way of knowing if it's going to ruin another batch of dough. I'm beginning a new starter tonight and I'll make do with commercial yeast for a few bakes.
Patsy
Yeah, the issue could be linked to enzymes, especially proteases, that can break down the gluten in the dough. A sourdough starter that's been sitting around for too long or isn't refreshed often enough can build up more of these enzymes.