increasing souerdough starter.
Hi,
Many questions on the subject, hope you can bear with me.
First a little history:
I did a batch of bread with 2,4kg (5.3lb) 10% protein wheat flour I portioned out 30% of the flour and added a little sourdough perhaps 30g (1oz) (=2%) and water so I got a 50/50% mix by weight. I think it fermented for 24h then I tried to use it for baking. The result was that the leavening was very weak.
The prescribed method:
I have heard that you should increase the sourdough in steps and I wonder if anyone knows the science on why that would yield a better result?
How does it actually work?
If I brainstorm a little the only difference I could come up with is that the enzymes in the dough have longer time to work on a bigger portion of the dough if you increase without steps. I was also thinking of natural selection, If the yeast and LAB does does not return to a high ethanol/acidic/co2 environment often, perhaps the pressure of selection favors less beneficial LABs and yeasts.
Is it true that one should increase a sourdough in stages or have you succeeded in a big increase?
Have any of you heard a scientific answer why one should increase a sourdough in stages?
What is the optimum percentage increase for leavening ability?
Changing the taste of a sourdough?
To change the flavor of a sourdough that had been in the fridge for a long time, to make it less sour:
I used less than 1% to inoculate a new batch of sourdough, I did that multiple of times and fermented in a warm place until I thought it tasted good. I ended up not baking with it, but would that have worked or would that sourdough have been increased so much that it would have been bad at leavening even after a couple of normal feedings?
If not what is a good way to change the taste of a sourdough?
All aside - the last question - yes - but it would still be called sourdough. Enjoy!
I've made levains with 1:15: starter:flour, but never gone as low as yours, i.e 1:27. For me, there might be a few reasons why I might not do that:
1) I generally make my levain 12 or max 16 hours before mixing the dough, just for scheduling convenience. My ideal temperature for fermentation is 19-21 degrees as I find that gives me the best leavening power and least sourness. For my starter, 1:15 takes about 16 hours to just be at peak. I think 1:27 would take longer than 24 hours. I find that ratios from 1:3 to 1:15 have really comparable leavening power, as long as my starter is not too acidic. If my starter is somewhat old, I will always go for a higher ratio.
2) My levains tend to contain a high proportion of whole grains or weaker grains. That means I try to prevent hydrating them for too long, or running the risk of having them in an overly acidic environment for too long, which will result in a lax dough with weaker gluten strength - this might give the impression of weaker leavening power even though it's not the case. I would be worried doing 1:27 with a 30% pre-fermented rye bread, for example. Doing that PFF either with a higher % of starter in the levain, or a multi-stage levain gives more control over the degradation of the flours involved before the mixing of the final dough. In the latter, the flours are staggered so it's even possible to start with stronger flours and end with weaker flours.
I don't see why a multi-stage levain would have less leavening power per se if always fed at the optimum stage. But I would be conscious of weaker dough strength if certain weaker flours have been fermented too long or if resulting %PFF is very high.
To make a sourdough less sour: I tend to feed at least 1:15:12; a slightly lower hydration helps. I try to keep temperatures at 19-21 degrees as far as possible for ideal yeast:LAB. Also reduce % of whole grains if possible.
Just my two cents. I'm sure members with more experience and knowledge with chime in soon.
-Lin
It is simply a case that it will be hard to judge when it is ready if your inoculation is very low. If I feed 1:5:5 I've got a good idea how many hours more or less it will take. If it was 1:100:100 there is a much larger margin of error, maybe it will take 12 hours or even 18!
By the way, what you're describing also sounds awfully similar to the panis respectus method.
-Jon
I have never tried to make a bread using a very small amount of sourdough starter. I have some thoughts but they are not based on doing so directly.
It's most common, I think, to inoculate the dough with 15 - 30% starter. Let's say 25% just for purposes of illustration. For 1 kg of flour, then, you would need 250g of starter. If you don't have that much, you will need to build it. You started out with 30g of starter, so you would need to build it up by a factor of 250/30 = 8.3. Half will be flour and half water: 1:4.15:4.15. That's not a very large feeding ratio and should create a nice active starter (or call it a levain if you want) in a relatively short time.
Is there a disadvantage to using a large feed ratio? Maybe. As usual, it all depends on many factors, especially whether you plan to feed like that repeatedly. If you feed with a high ratio, your starter or dough will spend a lot of time at a relatively high pH. This could allow undesired organisms to start growing. This would probably only come into play if you kept feeding at the high ratio over and over. Also, especially if you were to feed often, you would be likely over time to drive down the concentration of acid-creating bacteria. This would favor yeast at the expense of flavor and acidity.
The closest I have come to this condition was an experiment in which I salted my starter at 6% of the flour weight. Over the course of several weeks of daily refreshment, the starter apparently lost most of its acid-producing organisms. The starter always leavened bread well, but towards the end the breads had very little flavor. I might as well have used dried yeast and not bothered with the natural leavening. Salt at the level of 1 - 2% did not cause this loss of flavor, and now I routinely use 1% salt to slow down the development of the starter so I can feed it only once a day.
There could be another disadvantage to using a very high feed ratio. Fermentation will take a long time. Some flours wouldn't hold up for that long and they would start to deteriorate before fermentation was done. You can only know by trying it out.
I hope this is helpful.
TomP
Thank you all for the excellent feedback.
This is truly a great forum.
I have started to use the 1% salt method for my starter, thanks for that tip!
I raise my bread with 100% sourdough. I have a proofing time of approximate 6-7 hours @ 18-19C (64-66F) with 40% 50/50 levain. It feels quite long and I wonder if you use commercial yeast as well as levain? What are the pro/con of using commercial yeast as well, is 7h normal? When saying 7h it is for bulk ferment and final proof.
A time of 6 - 7 hours doesn't sound long for your temperatures. Using my starter at 30% inoculation, I expect to get 6 - 7 hour for bulk at 22 - 23C.
You can boost fermentation with commercial yeast but if you use too much, the bread will end up tasting more like yeasted bread and less like it was naturally fermented. I would start with 1/4 tsp of dry yeast, if you feel inclined to try it out. I've found that that quantity seems to develop on a similar time scale as my 100% sourdough doughs.
TomP