The Fresh Loaf

A Community of Amateur Bakers and Artisan Bread Enthusiasts.

"Proper" Sourdough pH?

davidg618's picture

"Proper" Sourdough pH?

I've search this site, and other baking related sites, top to bottom and have yet to find a number, e.g., 3.6, or 4.2, or even a range of values of "correct" pH for mature sourdough starter. All I've found is imprecise (and a few ambiguous) references to "low" pH. That's as about precise as the three blind men examining an elephant. I've been brewing beer and making wine for years, and routinely check pH with a meter that reports a number. Simple.

Can anyone tell me the "proper range" of pH in a mature sourdough starter?

Please, don't tell me about starter variability. I know that already. All I'm asking for is a range of numbers with single decimal precision.

David G.

xaipete's picture

My understanding from WGB is that is should be between 3.5 and 4. I bought some pH paper but I could never get my starter to register anything on the strips. I think the only way to get a really accurate read is to buy a pH meter. They cost about $100. That's a lot of money to spend just because I'm curious. If I had some other use for the meter I might consider it, but for now I'm trying not to think about it.


davidg618's picture

Not for the first time (I visit your blog frequently) your clarity, and "to the point" responses have been very helpful. I guessed, from experience with other fermentables, the range was between 3.5 and 5.0. Your reply to my query gives me confidence in my guess. I own a pH meter that has served me well for more than a decade. Thank you.

David G.

xaipete's picture

I wish I knew someone who lived around me that had a pH monitor.


Mainly's picture

Pamela if you are reading this in 2009 wait about 14 years and check for pH meters.  They will be available for as little as $10.00 with free shipping.  Also buy some of the company stock (AMZN) asap.

davidg618's picture

I'm not new to bread baking, but I am new to bread baking websites. Please, what is WGB?

Thank you,

David G.

flournwater's picture

Peter Reinharts  -  Whole Grain Breads

proth5's picture

I measured mine  and it is 3.5

I've measured some other well cared for soughdoughs and the pH is 3.5

So I'll add another voice to the 3.5 or so pH...

Janknitz's picture

if we could collect data from a group of well-developed starters and get some good hard numbers?

It's too bad simple ph paper doesn't work. Then we could set parameters (i.e. hydration level, point in the metabolic cycle, even type of flour) and have a large group measure ph and compile the data.

It might yeild some interesting results.

davidg618's picture

that's just the first of questions. What I'm trying to understand is how best to develop the "right" balance between bacterial byproducts and yeast byproducts. Bacteria contribute mostly flavor; yeast contributes mostly CO2. Yes, I know bacteria also emits gas, and yeast also effects flavor, but I stand by my arguement.

I have a six month old KA sourdough starter I've been maintaining at 100% hydration, and a very new--less than a month old--starter, alledgedly containing San Francisco bacteria and yeast. I maintain the latter in two hydration states: 200% and 65%. The very liquid SF starter provides excellent  1st and 2nd proofs in near record time, and excellent oven spring. However, its sourness is nearly undectable. The same strain, maintained at 65% hydration, is a noticeably lower performer in proofing and oven spring, and doesn't exhibit a discerable difference in flavor. Admitedly, the lack of sour flavor may be due to the starter's youth.

The KA starter has a distinct sour flavor, wonderful on the pallete, but is disappointing in proof times, and oven spring is virtually absent.

I've experimented with varying proof times, retarding (refrigerating) up to 21 hour) but the final results--for all three seed starters--don't change appreciably. I've done formula with starter freshly fed from the crock, starters I built, tripling their weight each time over three feedings with the same non-varying results.

What I'm trying to achieve is the well sprung, near lip-puckering sour loaves, reminiscent of the SF sourdough I bought when I lived in Monterey, and subsequently when work took me frequently to Bagdad by the Bay. 

I'm open to trying anything short of offering my first borne (You wouldn't want him; he's 54, bearded, and opinionated.). My science training tells me "Look to the science", the artisan in me says, "Ignore him!". I'm trying to find that balance too.

I will continue my trial and error, scientific and artisanal, experiments, but if there is anyone out there with suggestions I'll listen--and likely try--anything that sounds rational and reasonable.

Like my New Age friends say, "The journey is what's important, not the goal."

David G.



not.a.crumb.left's picture

Sorry David, this is a very old thread but you captured very succintly  something that I am exploring right now

I just ordered a ph meter in order to find out more about my starter...which is currently a 80% hydration starter fed twice....

I get reasonable oven spring and my starter is on a feed twice a day double/triples and seems to be happy and healthy.  But but..Doubt is creeping in  and I wonder whether it could be better considering some oven spring that I see on IG and here! I am also intrigued about the LAB/yeast ratio as I have a mildly sour which I like but it would be nice to experiment how to explore different aromas...

If you have any advice that would be much appreciated. I have been going over online scientific papers and find it amazing how many different strains of LABs  there are and how different they can behave. Wouldn't it be nice, if I knew which one I have which came to me via Germany and now lives in UK!    Kat

jammv1's picture

my sourdough starter is 2yrs old and is ph5.16

My bread always has great flavour and crust is crunchy and the crumb is light and airy without having too many huge holes. The flavour is always rich too.

So this ph seems to work in my books given ph7 is neutral I don't think you want it too acidic as this would have a negative effect on the amino acids and good bacteria.

margoooo's picture

I am doing a bit liquified starter, I love the flavour and I just checked the PH it is 5 different from  my other starter that where the PH is 4.2, is your starter a bit liquidy?

doughooker's picture

My preferred method of making sour bread doesn't use a sourdough culture. I add the souring agents directly to the dough as inspired by this paper:

I grew up on Larraburu sourdough and after many, many test bakes was able to adjust the balance of the two acids so that it tastes just like I remember Larraburu tasting. I find I have more control over the flavor and the proofing time is greatly reduced.

Sourdough will contain lactic and acetic acids whether they come from a sourdough culture or are added by the baker as ingredients. It's six of one, a half dozen of the other. Here is the recipe I use now:

As the recipe says, you MUST use instant dry yeast. Active dry yeast will give it an undesirable flavor.

phaz's picture

Best ph is 3.72248 - and as you'll never be able to determine that - forget about it - never recommended to worry about nothing! Enjoy!