Reducing "sour" flavor
Hello all! I'm baking the recipe bellow every week or so with good results (after a lot of practice). Unfortunately it's coming out a tad too sour (ok for me, but not for most people). I tried searching the forum a bit but most people are actually looking for more "flavor" and not the other way around.
I was hoping I could get some advice in order to get a less sour flavor.
Starter:
100% hydration, with whole spelt (was using bread flour before but I noticed no different regarding final acidity).
In the afternoon, hours before the mix, I take it out of the fridge, throw away almost all of it and refresh.
Recipe (70~75% hydration, 20% whole spelt):
255g white bread flour (~11.5% protein)
40g whole spelt flour
220g water
25g starter (100% hydration, close to peak)
Method:
mix everything except salt
wait 30m
salt + stretch and fold
wait 30m
stretch and fold
bulk proof overnight at room temp. (8h)
rough shape (at this point it puffed ~60%)
wait 15 mins
shape into a boule
proof (usually 2h10m)
bake in an iron pan (20min w/ lid then 25min without)
Introduce another feed to your starter. Try an overnight feed and come morning take off some starter, give it another feed of 1:2:2 and use 3-4 hours later. You can also use a bit more starter. So something like this:
Morning of:
when active but not yet fully peaked, use. About 3-4 hours later.
Recipe (re-arranged):
Then watch the dough and not the clock.
How does multiple refreshing helps achieve a less sour loaf? Just trying to understand the reasoning.
I'll definitely try double refreshing though. First I might try the same inoculation as I'm afraid if I use twice the starter amount it's going to over-ferment overnight.
An overnight proof at RT looks suspicious to me. I Do a two step build with about 25% of the flour (100 or 125% hydration) overnight and then assemble the total the next morning. Good flavor but not noticeably "sour".
Yeah, I'm afraid the long bulk is the main contributor. I had to adapt the method to my schedule and this was what ended up working best.
Isn't all sourdough using the indirect method (two step)? I'm assuming you mean to start the bulk in the morning with 25% inoculation.
Yes. Preferment is combined with the other ingredients the next morning. If you need to bake first thing in the morning, maybe you could try to do your overnight in a cooler
How do you keep your starter? I keep my starter in the fridge, and it has lost most of the sourness.
Use a higher percentage of pre-fermented flour (like 25%), and use a very active and fairly young levain.
Be sure that your refrigerator is cold enough to really slow down the LAB (below 4°C).
Mix at night, let it BF for 30-45 min; chill 1 hr, fold; chill 1 hr, fold; leave in the refrigerator overnight at 4°C.
In the AM, take it out and final shape, proof and bake.
After one cycle, adjust what needs to be changed. You are trying to reduce the time that the LAB have to build acid while still allowing the dough enough time to develop strength. Time below 4°C doesn't count for LAB growth (unless it is a full day). But you need an active levain to get it to develop enough yeast to drive the final proof. You could also add a pinch of IDY when you mix if you think your levain is not active enough to get what you need overnight.
Adding honey to the recipe?
What is your schedule and how much time can you spend working on a dough? Problem is the less tangy sourdoughs have higher percentage starter and are quicker so you need to find a way around that.
If the bread is sour enough that you need to eat it with a side of Tums adding honey is not going to help.
And fructose promotes increased acid production. In fact, when I want an extra sour batch, I add 2% pure fructose to the dough (not to the levain) and it produces an increase in TTA that is independent of other factors (and yes I have quantitative data to support that statement if anybody is interested).
The outline of why can be found here: http://www.thefreshloaf.com/node/10375/lactic-acid-fermentation-sourdough
Yeah, I'm realizing I got the inoculation logic all wrong. I think I could build it with a higher inoculation the evening/night before and retard the bulk phase in the fridge. Fridge space is at a premium but I see no other way around right now.
Funny enough I'm essentially allergic to fructose so that is not an option.
Unfortunately, you are using a recipe that's geared towards developing more sour taste. Low percentage inoculation and long fermentation will do it every time unless you are lucky (you apparently are not) and your starter does not produce much acetic acid. The answer is a higher percentage of flour in the starter - like 20%, which allows for shorter fermentation time, and if that still does not help - spiking the final dough with yeast.
Thank you for your answer. I had no idea that was the case (-inoculation +time => +acid), in fact I thought it was the other way around (:facepalm:).
Could you kindly explain why is that? Just enough so I can direct my research.
But insensitive to TTA. And flour acts as a buffer to hold the pH up and allow the LAB to replicate. The LAB stop replicating (but continue to turn sugars into acids) at ~pH 3.8. So in a levain the LAB replicates until the pH reaches 3.8 and then settles down to making acid with whatever population there was. A levain with more bran/whole grain in it will allow the LAB to replicate longer, but eventually the LAB stop replicating. After that the yeast just grow exponentially until they deplete the available sugars (of all types, though they prefer some over others). When you dump the levain into the dough and mix it, the flour does two things. It buffers the pH up to somewhere on the high side of 5 so that the LAB again start to replicate, and it provides a new supply of sugars.
I think what happens when you use a small inoculation of starter is that the LAB population keeps growing all the way through BF and proofing, while if you use a larger levain, the LAB population stopped increasing before the levain was ripe and thus reduced the rate of acid production. Then if you use the levain when it is maximally active and in large quantity (25% of pre-fermented flour), you give the LAB much less time to make acid with a smaller population which yields less total acid.
I have found that if you run a levain very wet (250% hydration - i.e., all of the water in the formula) and use water that has been used to soak wheat bran (hot soak 2 hrs but filter the bran out and cool it before you use the liquid), you get a lot more acidic (TTA) bread. I judge it to be about the same as using whole grain flour for the levain but without the bran. So you can make what appears to be a white loaf that is about as sour as a loaf made with whole grain. The extra water seems to dilute the TTA in the levain and further acts to hold the pH up longer. If you can get one more doubling of LAB population before it stops replicating you effectively double the rate of acid production after you mix the dough (or correspondingly - if you stop the LAB replication early, you get less total acid).
And remember that you taste lactic acid as sour and you smell acetic acid as sour simply because of the difference in their molecular weights and thus their vapor pressures. Thus it is counter-intuitive, but if you add a little vinegar to your levain, it drops the pH and slows down the LAB, and the acetic acid will mostly dissipate later in the process (during baking and after the bread comes out of the oven) so that while it may smell slightly sour, it won't taste as sour. And while the yeast also suffers a little, the net effect works for you (and reducing the salt a little might be enough to make up for it).
Today I had the full day at home and I tried using a more conventional inoculation ~15% (up from 4%) and the dough indeed came out less sour.
I could even have stooped the bulk fermentation earlier as it grew ~75%.
I'll experiment more next week.
I would like to add my personal experience in controlling sourness:
When you feed your starter, try to control the amount of starter from previous feeding, so that you could reduce carryover of acid-generating bacteria. I usually just use 20% of flour weight.
Use a younger starter, preferably before full rise. I found a lot of books say that 7-8 hours of feeding starter is too long. I usually start mixing 5 hours after the last starter feeding.
Control fermentation time to less than 5 hours, and fermentation temperature 21-24 Celsius. I found that temperature and fermentation time impacts greatly on the sourness of the bread.
@xinting - on your first point, it is not the amount of LAB that you bring to the refresh cycle so much as the post-refresh pH. If the post-refresh pH is below about 5.0, and the LAB stop replicating at a pH of 3.8, then over the full refresh cycle you don't grow back enough LAB to replace the population that was in your original culture. Your 20% number is good, but not for the reason you state. And if you use whole grain flour instead of white flour the post-refresh pH goes up even more and stays up longer which works to the benefit of those seeking sour.