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Getting the right acidity in the sourdough starter

caviar's picture

Getting the right acidity in the sourdough starter

I recently bought Peter Reinhart's book Wholegrain Breads and am making his "mother starter" where he advises to test for a proper PH of 3.5 to 4.0. Litmus paper only shows if the material is acid or alkaline.  Does anyone have experience in testing the adidity and if so where does one find reasonable testers.

LindyD's picture

I have a metal pH probe that I use in my garden, but I think a better solution would be to visit an aquarium or gardening center and pick up a pH liquid test kit. They cost about six bucks and are good for around 130/150 tests.




proth5's picture

I keep koi and am pretty serious about my water quality so I have a very good test kit for pond water.

Problem with these kits is the range. They are very accurate in the range in which the fish live.  This pH is much higher than that of most sourdoughs.

Also, garden soils in those ranges are just a little too acid  for most of the plants that I grow - so again, although I don't have much experience with soil test meters, I can imagine that the range might be limited.

I was able to find pH test strips by doing a search on line.  I got pH test strips from  They sell non-bleeding test strips with various ranges that read well even if the test solution (say a mixture of levain and distilled water) is cloudy.  It is a one person operation, but I was happy with the service, product and prices...

Hope this is helpful

caviar's picture

  Thanks for the suggestions. I'll try the PH test paper and maybe later I will be able to tell by tasting.

Soundman's picture

hi caviar,

I've never tested my sourdough starter's pH, but why not? I have a pH tester for my garden, and I probably can use it to test the starter's acidity. I would have to make sure it was really really clean first!

If you decide you need such a gizmo, there are all different kinds at all different price points, available on the internet. Since I'm serious about my garden and the pH of the soil in it, I bought a good quality pH tester from But there are much less expensive ones out there that probably will do the job.

Good luck,

Soundman (David)

Mike Avery's picture
Mike Avery

A friend bought a pH meter.  He used it a few times and now says tasting the starter tells him all he needs to know.


pH test paper, rather than litmus paper, will change to different colors depending on the pH of the stuff it's expsed too.  You  can get a big box for less than $20.00if you look around online.


And when you get past needing to know the pH of your starter, you can give or sell the pH test strips to others.




antonis's picture


Dear caviar, why do you need such a device? Are you sure you need it?

You may have two doughs of equal pH, say 3.9,

and one to taste not sour at all and the other to be strongly sour.

 pH and acidity/sourness are two different measurements. 

yves's picture

As far as i understand a starter plain and simply will not look like or behave like starter unless it reaches the required acidity and homeostatsis. So you dont really need to test. Having said that I did a test of mine, but unfortunately the pH test kit didnt go low enough. But the fact that the pH was below 5 was good enough for me.

Personally i wouldnt worry too much about the acidity or pH test kits. People were making starter for thousands of years before we even knew what pH was, so one can hardly consider it a firm requirement. :-)

If you can divide and double your starter every 24 hours and observe a regular doubling in volume over the 24 hours following a feed consistantly over a week then you almost certainly have the right thing. If it wasnt the right thing it would behave differently and youd almost certainly know it.