Rough Guide to fermentation time using sourdough starter

[MikeSwifty]

The usual recommendation when using sourdough starters instead of commercial yeast is to replace the yeast with starter equal to up to 40% of the total flour in the recipe/formula.  But how do you know how long it will take before the dough is ready for the oven?  I've looked through the forum and found a few experiments conducted to help determine the answer.  Please note the assumptions for these times:  dough is at room temperature (RT) unless otherwise noted, starter is kept at 100% hydration (feeding equal parts flour & water by weight), starter has been recently refreshed (not used straight from the fridge). 


    40% starter:  3-4 hours at RT  (MikeSwifty)
    20% starter:  9-10 hours at RT (Pete-zza)
    10% starter:  12-14 hours at RT (PizzaBrasil)
3-3.5% starter:  20-24 hours at RT (PizzaBrasil)


The info about 40% starter comes from my own personal experience.

The info from Pete-zza can be found in the thread:  "Re: Tom Lehmann's NY Style Pizza".  I've tried to give a little summary below.

Reply #151, 20% starter, hydration not specified, but mentions that it
"was like a pancake batter":  45hrs refrigerated, 2hrs RT, then baked. 
Uses an autolyse--reported as "exceptionally good". 

Reply #165, 20% starter, stiff (63% hydration):  9-10hr RT--reported
"the pizza was one of the best Lehmann pizzas I have made, with a crust
as good as any I have made in my many experiments with the Lehmann
dough--whether based on retardation (refrigeration) or not. The crust
was chewy yet soft and tender and with a nice pleasant flavor.

Reply #175, 20% starter, stiff (63% hydration):  simplified dough
preferment process, uses an autolyse, uses a food processor instead of
stand mixer, 10hr RT--reported only a small amount of expansion seen in
the dough but, "it had a perfect amount of elasticity and extensibility"
and produced "a pizza of very high quality."

http://www.pizzamaking.com/forum/index.php/topic,576.160.html


The info from PizzaBrasil can be found in the thread:  "Test of quantities of pre ferment in one day fermented dough"

(Using 100% hydration starter refreshed 4 times in 24hrs)

25% starter:  9hr RT + 15.5hrs fridge--reported good result
25% starter:  4hr RT then divided, 13hr RT--reported good result

15% starter (reported as 37.5gm for 250gm flour): 10hr RT--reported good
taste but dough did not develop too much and showed lack of color
 
20% starter (reported as 50gm for 250gm flour):  10hr RT--reported good
taste but dough did not develop too much and showed lack of color

15% starter: 2hr at 68 degrees, divided, 6.5hrs at 68 degrees, 1.5hrs at
RT, baked in WFO--reported good color, very good tasting.

20% starter: 2hr at 68 degrees, divided, 6.5hrs at 68 degrees, 1.5hrs at
RT, baked in WFO--reported "superb" and "excellent".

[JimmyG]

Mike,
You picked a very loaded question that depends on quite a few variables. The best answer I can provided is, it depends. Unfortunately there is no simple answer. Factors that influence how long it will take before the dough is ready include: How long does it take your specific starters to double? What temps are you keeping them at, 68F (room temp) or in the 70Fs? How active was your starter before you added it to you to your final dough? What was your final dough temp after mixing? What was the pH of the dough? What type of flour are you using in feeding your dough? As well as many other factors.

I know this is not the answer you were looking for, but the best answer I can give is: play around with different recipes, formulas and temps, keep a log of your trials and find out what works best for you.

[TXCraig1]

Jimmy is right. You have to experiment. For me, it's 1.5% for 48 hours at 65F.

CL

[Jackie Tran]

Along with what Jimmy said, a few other factors that also affect fermentation time.  

Flour:  doughs made with weaker flours ferment faster
Hydration:  higher hydrated doughs (relative to the flour used) will ferment faster
Salt: doughs with less salt ferment a bit faster (I believe)
Aeration of starter: whipping air into a starter prior to using will make the dough ferment faster
Quantity of dough:  a bigger mass of dough will ferment faster (the mass dough effect).  Smaller batches cool off quicker.
Gluten structure:  a dough with a stronger gluten matrix or well developed gluten structure will seemingly ferment faster as well.  It basically tents up the air inside better.

There are other direct and indirect factors I am sure, but that is about as much as I know.  

BUT, generally speaking I go by these ball park numbers and adjust accordingly...
1% at room temps of 75F ~ 24hrs.
2% at room temps of 75F -> about 20h
5%  at room temps of 75F -> about 16 hours
10% at room temp of 75 -> about 12 hours
20%  "   "  about 8 hours
40%  "   " 4 hours

Of course, along with the generalize times, you will also have to smell and feel the dough at different stages to have a good assessment of the progress of the dough.  As far as when to ball or when to use the dough is a personal choice.  Some like using younger doughs while others like a more mature dough.

Chau  

[MikeSwifty]

Great (and practical) stuff, I love it!  While I agree that experience is the best teacher, with a forum like this, those with no (or little) experience can also draw on that of others until they develop enough of their own.  For me, I've been scrounging around the forum looking for clues.  I decided it'd be nice to have the info all together under "Starters/Sponges" for those, like me, who aren't sure what type(s) of pizza they'd like to make but do know it's going to be made with 100% sourdough starter.  I was hoping if I "tossed a brick" I'd "get a jade" as the Chinese say (ie, threw out my worthless idea to get your priceless one).

Thanks guys!

[barryvabeach]

Mike, thanks for the post.  I have been making pizzas for years, using commercial yeast and when I first switched to started using starters, I wanted some general guidelines to work from.  Your post would have been a great help. Right now I am at 2.75% Ischia  18 hours around 68 degrees,  then 4 hours refrigerated - though I use 100% whole wheat, so it  is different then those using white flours.  I still am not sure whether the longer fermentation times will be better than shorter times with higher starter.

[MikeSwifty]

Barry,

Do you use any sugar or honey?  How much salt?  I've been wanting to do a whole wheat crust for awhile and now that I'm happy with my regular crust that's where I'm headed next.

[charbo]

I'm at 30%, 7 hours, 76°, whole wheat.

Edit:  With winter wheat, the time is more like 6 hours.

By the way, I would call this a levain, not a starter.

[barryvabeach]

Mike,  I don't use any sugar, salt is at 3%.  The other complicating factor is we are now heading into spring.  Over the winter, the house is usually around 68,  in the dead of summer it will be about 72 since we run ac,   For the few weeks we don't run heat or ac,  temp in house can be as low as 65 and high 70's so overnight fermentation can vary pretty wildly. 

[Everlast]

If I use 2% Ischia starter and ferment dough (Caputo 00 flour, 2.8% salt, 62% HR) for 36 hours at 65F then another 12 hours at 78F, will that yield more or less sourdough flavor than using 10% starter for 12 hours at 65F? Or should the flavor be similar? In short, does the amount of starter directly affect the amount of sourdough (tangyness) flavor in the dough? If that's the case, do people intentionally adjust the level of starter to the amount of sourdough flavor they desire, then use the recommended fermentation schedule accordingly?

[dellavecchia]

If I use 2% Ischia starter and ferment dough (Caputo 00 flour, 2.8% salt, 62% HR) for 36 hours at 65F then another 12 hours at 78F, will that yield more or less sourdough flavor than using 10% starter for 12 hours at 65F? Or should the flavor be similar? In short, does the amount of starter directly affect the amount of sourdough (tangyness) flavor in the dough? If that's the case, do people intentionally adjust the level of starter to the amount of sourdough flavor they desire, then use the recommended fermentation schedule accordingly?

The "tangyness" comes from fermentation that is mature. You can mature a dough in 12 hours using say 30% of flour, or do something much slower. The temperature that you ferment is the determining factor in the final amount of tang, along with how much starter you use to get there.

Craig's long, slow workflow achieves consistency by keeping the temp constant. It also imparts good flavor by fermenting for a long period of time. I believe there is a texture factor as well from the nearly three days of fermentation. But you can get basically the same results with a 24 hour workflow using a modest amount of starter and a mild temperature.

John

[Everlast]

Thanks John, that is exactly the answer I was looking for. I'm going for round three this weekend using my Ischia starter and am hoping to develop the flavor I'm looking for using Craig's workflow. I tried 1.5% starter using Craig's workflow last weekend and it didn't turn out too well (possibly overwet dough from a weighing error, not enough rise). I'm guessing my starter doesn't pack as much punch as Craigs, so I'm going to up my starter to 2%.

Damian

[TXCraig1]

Thanks John, that is exactly the answer I was looking for. I'm going for round three this weekend using my Ischia starter and am hoping to develop the flavor I'm looking for using Craig's workflow. I tried 1.5% starter using Craig's workflow last weekend and it didn't turn out too well (possibly overwet dough from a weighing error, not enough rise). I'm guessing my starter doesn't pack as much punch as Craigs, so I'm going to up my starter to 2%.

What temperature did you ferment at? How did you maintain the temperature? Did you confirm that it was not colder than your thought? AOTBE, a wetter dough should have risen more.

CL

[Everlast]

I'm using a 36 quart Coleman Extreme cooler with 1 cup of frozen water that I'm changing out every 4-6 hours. I leave the thermometer in the cooler to check the temp and it was maintained at 65F pretty much down to the degree for the entire 36 hour fermentation last time around. Here's a pic of the cooler and my Ischia starter. This is my starter about 3-3.5 hours after removing if from the fridge today and feeding it. The top of the brown rubber band is the level after feeding, the colored rubber band is 2" above that.

Damian

[TXCraig1]

Everything looks good to me. Hopefully you will see better results with 2%. I would normally encourage someone to start with 2-3% and then work their way down. I wouldn't change anything else.

[Pete-zza]

If I use 2% Ischia starter and ferment dough (Caputo 00 flour, 2.8% salt, 62% HR) for 36 hours at 65F then another 12 hours at 78F, will that yield more or less sourdough flavor than using 10% starter for 12 hours at 65F? Or should the flavor be similar? In short, does the amount of starter directly affect the amount of sourdough (tangyness) flavor in the dough? If that's the case, do people intentionally adjust the level of starter to the amount of sourdough flavor they desire, then use the recommended fermentation schedule accordingly?

Damian,

Out of curiosity, I wondered if member November's methodology as discussed at Reply 6 at http://www.pizzamaking.com/forum/index.php/topic,5028.msg42572.html#msg42572 would apply to a natural starter, such as your Ischia starter. It seems to me that so long as the starter used for the two scenarios is the same, the methodology should work. So, I took a stab at calculating how much of your Ischia starter would be needed if you decided to use only a 12-hour fermentation period at a temperature of 78 degrees F (25.6 degrees C).

For the reference rate, I used the scenario in which you would ferment the dough for 36 hours at 65 degrees F (18.3 degrees C), followed by 12 hours at a temperature of 78 degrees F (18.3 degrees C). For this scenario, the amount of starter would be 2%. For the predicted rate, I used the scenario in which you would ferment the dough for 12 hours at 78 degrees F.

Using the online calculator at http://www.ecalc.com/ to do all the calculations and attempting to apply November's teachings, I came up with a value of 11.43% Ischia starter to equate the results of the two scenarios. If that number is correct, it is not far off from the 10% figure that you mentioned above. What remains to be seen is if the two different doughs would perform the same and produce the same results. For example, possibly they would be similar from a fermentation and management standpoint but yield different tastes in the finished crusts.

Peter

[TXCraig1]

Peter,

I played with this some, and I had a couple questions and comments.

When I used your scenario:
2% culture for 36h @ 65F + 12h @ 78F
converted to 12h @ 78F

I get 5.26% for the new culture amount.  I don’t know why you got 11.43%? I ran November’s example in my spreadsheet, and it seemed to tie (more on this below).

Interestingly, when I use Everlast's scenario:
2% for 36h @ 65F + 12h @ 78F
converted to 12h @ 65F

I get 9.70% which is really close to his 10% (but I don’t believe this is an accurate conversion).

I plugged in some of my observations using Ischia; when the changes in time were less than 12 hours, the variance between November’s formula culture % predictions and my observations were very small – generally plus or minus only a couple tenths of a percent or so – some were right on.  As the change in time got larger, the error also increased. When the change in time approached 24 hours, the errors were getting as high as 300% (as in the formula predicted 2.4% and I used 7.5%). All the predictions when going to a much shorter time (i.e. 48 to 24 hours) were way too low. I would suggest caution when trying to use November’s formula to make large changes in a SD formula.

With respect to November’s example, I can’t recreate his sin calculations. For example, he states:

sin (20 / 36)^2.1 = 0.2869326322

Excel or any calculator I plug it into says it equals 0.2609281104. This appears to be true of all of his sin calculations. I thought it might be rounding, but even taking the numbers to the extremes of rounding, I can’t get all the way to his numbers.  Do you know if he is doing something other than what one would expect when he sees sin(x)?

With respect to testing my spreadsheet, I got very close to his example but not exactly, however it looks like the difference is in the sin calculation.

Craig

[TXCraig1]

Here are the numbers I got for your example:

[Pete-zza]

Craig,

I went through the exercise just for kicks and wasn't completely sure of my math either. For the sine calculation, I used the online calculator at http://www.ecalc.com/ with the sin key. To be sure of the calculations, I ran November's numbers through the calculator first before using it for my calculations. When I got his numbers, I used the same approach for my sin values.

For the sin calculations, I got these:

sin (18.333/36)^2.1 = 0.2400453766672
sin (25.556/36)^2.1 = 0.6517495045674

I did everything else with pencil and paper and my desk calculator. For the reference, I got this:

[(0.24004537 x 36) + (0.651749505 x 12)]/48 = 0.342971409

For the final calculation, I got this:
(0.342971409 x 48 x 0.02)/(0.24004538 x 12) = 0.114302191 = approx. 11.43%

Peter

[TXCraig1]

OK, I see what he was doing now. I was reading his formula like it would be written in Excel on on ecalc. He is leaving off the outer parenthesis around the entire argument.

Correcting my spreadsheet, it ties to November's numbers exactly. I get 5.078% for your example (2% culture for 36h @ 65F + 12h @ 78F converted to 12h @ 78F).

I think you have a couple errors

Check sin (25.556/36)2.1 = 0.6517495045674

I think it should be = 0.467947873279

Which will give you

[(0.24004537 x 36) + (0.467947873279 x 12)]/48 = 0.297020996

And your final formula would read

(0.297020996 x 48 x 0.02)/(0.467947873279 x 12) = 0.050778476

or 5.078%

You had (Reference rate avg x 48 hours x 2%)/(65F x 12hours) - that was what Everlast asked, but not your example which would have been (Reference rate avg x 48 hours x 2%)/(78F x 12hours) which is what I have above.

Everlast's scenairo:2% for 36h @ 65F + 12h @ 78F converted to 12h @ 65F yields 9.899%

Craig