The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

The pH of Dough

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louie brown's picture
louie brown

The pH of Dough

After seeing Eric's reference to Bwraith, and after reading through his blog, and after going from there to a variety of other technical threads, all of them useful if difficult for a nontechnical person like me, I am wondering if there is any information available on the optimal pH level for any given bulk dough or formed loaf. 


In a mention by another member of a Japanese book on baguettes, I recall a reference to the desired pH of certain loaves. I have not been able to find it again, nor have I found any discussion here of the pH of dough or loaves.


It strikes me that the ability to know the optimal pH for stages of dough and formed loaves for any given formula could be a big help. Can anyone point to information here, or perhaps offer some?

LindyD's picture
LindyD

http://www.dakotayeast.com/help-fermentation.html


According to the folks at Dakota Yeast, the pH has little effect on yeast fermentation unless it drops below 4.0.  The article also states that the pH within yeast cells remains constant at 5.8.


I wonder if that applies to wild yeast as well.

proth5's picture
proth5

(Speaking of bwraith) I did some pH measurements on my levain under different feeding conditions.  It pretty consistently had a pH of 3.5.  So I'm thinking that wild yeasts are more adapted to living under lower pH conditions.


Hard for me to measure the pH inside the yeast cells, though.


Hope this helps.

Mini Oven's picture
Mini Oven

if you have extremes like very low or high water pH, then something needs to be done to bring the water in line.  It plays a roll with sourdough starters if only discards are used as a dough, the low pH if it dips 4 and under (high acid) will tell you that added yeast will not raise it.  Adding flour (which has a higher pH) and water (also higher) will raise the pH telling yeasts they have food and can get to work.  Raise the ash content of that flour (like using bread flour) and the yeasts will not be so quickly affected when the pH drops during fermentation.   Fermentation causes the pH to slowly drop in the dough.  The longer it ferments the more it drops.  The exact readings and speed will vary with temperature and type of flour and other ingredients. 


In my opinion, observing the dough will tell you more than watching the pH.  You can be a great baker and never had tested a single dough for pH content. 


If only it were so simple as saying,  "At so-and-so a pH reading, the fermenting is done enough to bake."  That would be wonderful!   I betcha, non sourdough doughs will have a higher pH value when ready to bake than sourdough doughs.  Then again, my sourdough culture may have a lower or higher pH than LindyD's when it is ready for the oven, they may have different strains of yeasts and bacteria, all contributing to the end decision to when the loaf has finished fermenting enough to bake.  Fermenting is only part of the dough picture.  Granted it is a big one but the pH level will not tell you your gluten development or if your dough needs more water or an extra fold or if it will taste good.  That's your job. 

louie brown's picture
louie brown

In particular, I agree with the ability to judge one's own starter, fermentation, gluten development, etc. That is pretty much the baker's goal.


I am just wondering if the pH of the dough can be an additional tool.

Mini Oven's picture
Mini Oven

or an indicator of activity.  I'm the last one to say don't do or try something.  Do it!  There are different ways to go about measuring it.   There are papers and strips and I've used a pool kit on occasion.  There are hand held gizmos too!


If you're curious, by all means investigate!   :)

LindyD's picture
LindyD


Some useful information for all you "sourheads" out there:


Overmatured sours, i.e., replenished sours matured over 8 hours at 77F, may build up excessive acidity and the lactic acid bacteria will start to inhibit the propagation of yeast cells, i.e., slowing the leavening activity in the sourdough.


A good and fully matured functional sour has a pH of 3.9-4.1 and a total titratable acidity (TTA) of 13-15 ml. Sours that develop acidity equal to a TTA of 18-22 ml or higher with a pH of 3.8 or lower will gradually lose their ability to produce enough carbon dioxide to leaven bread loaves. Having a high acid content also makes doughs softer and makes their cell structure break down during rounding and moulding. This tends to result in an irregular cell structure with thicker cell walls in the bread crumb and a tougher bite. This effect is intensified in doughs with a relatively high water absorption (over 62% of flour weight). However (for all you artisans out there), bread of this type is acceptable as "signature" bread served in restaurants or for personal use or for artisan type bakeries.


Other useful information concerning industry "normal" pH and TTA in breads and their process:


Sourdough starter 3.9-4.1 pH 14-16 TTA

Mixed dough 4.6-4.8 pH 5-7 TTA

Proofed dough 4.2-4.4 pH 9-13 TTA

Crumb 4.3-4.5 pH 6-7 TTA


*TTA values are expressed as ml of 0.1 N NaOH per 20g sample (sourdough starter containing 47.6% flour) titrated to pH 6.6

http://www.nyx.net/~dgreenw/howdoesonemeasurethephofso.html


Not sure who Darrell Greenwood is, but it's a very interesting site and there's lots more to it than the above snippet.

louie brown's picture
louie brown

At least there are a couple of numbers there for basic reference.


I believe that Darrel Greenwood kept the old rec.food.sourdough list, a highlky contentious and often silly list that nevertheless had a number of expert sourdough bakers. That guy Samartha who had (has?) a Detmold page somewhere, was a member.