pH 2.5 - 4.5 ColorpHast strips also read .3 low?

General Homebrew Discussion
1

Does anybody know if these lower pH range ColorpHast strips, like the normally used 4.0 - 7.0 range strips, measure at .3 lower than the actual pH?

I’m monitoring a full volume wort lacto sour, to begin boil when I hit ~3.6pH.

I assume that is the case.

2

http://braukaiser.com/wiki/index.php?title=An_Evaluation_of_the_suitability_of_colorpHast_strips_for_pH_measurements_in_home_brewing

My experience agrees that the read .3 low. I use a ph meter now but used colorphast strips for a long time and found I was always at what bru’n water predicted if I added .3. Just realized you asked about a different range so I can only guess it’s the same

3

Thanks Andor.  I was being conservative of use of equipment with the live culture, and I’m kinda lazy, but in fact have a very good lab pH meter that has a new electrode.

So I compared the ColorpHast strip reading with the pH meter reading and found that yes, the lower range ColorpHast strips also read ~.3 lower than the actual pH.

Cheers!

4

Awesome good info. I’m sure that’ll help someone else out