PH levels with strips

I took some test readings with Precision Labs test strips and just wanted some backup as to their validity. A regular tap water reads about 5.2. A reading of boiled water reads about 5.6. A reading of water with grains reads about 4.8. A reading at boil reads 4.7. A final reading before pitching yeast read 4.6. This sound about right, or at least normal?

It is hard to say what a normal water pH is but those mash and boil pHs are clearly wrong.

If you mix distilled water with pilsner malt, the pH will be around 5.8. With most water sources, it would be higher. Assuming you have not added acid, 4.8 is essentially impossible regardless of the grain or water used.

Aloha_Brew said:

I took some test readings with Precision Labs test strips and just wanted some backup as to their validity. A regular tap water reads about 5.2.

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Tap water from a well could be as low as 5.2. For city water that is too low.

Aloha_Brew said:

A reading of boiled water reads about 5.6.

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The pH of well water will increase as it is boiled. It is not reasonable for boiled potable water to have a pH as low as 5.6.

Aloha_Brew said:

A reading of water with grains reads about 4.8. A reading at boil reads 4.7. A final reading before pitching yeast read 4.6. This sound about right, or at least normal?

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These are also all low. Some strips are thought to read 0.3 low. Even adding 0.3 to all the numbers you listed gives values which are appreciably too low.

So, it seems the strips are unreliable. Are they affected by temperature at all?

Otherwise, I guess a digital meter would be preferable. Any recommendations out there for a specific brand or site?

Everything is effected by temperature. I've hypothesized that the higher temperatures of mashing might destroy the dyes but others say this is not the case. In any event they are not, as you have seen suitable for brewing.

I'm not familiar with the under $100 meters so I just say look for:
•Precision (readabilty) of 0.01 pH
•Accuracy of 0.05 or less - less is preferable
•2 buffer calibration
•ATC
•Automatic buffer recognition

http://www.eseasongear.com/hahi98waphtt.html

This one is popular with homebrewers. 0.05 accuracy and ticks all of AJ's other boxes.

I have one and like it, when the probe starts performing poorly, I intend to upgrade personally as I become more and more convinced that pH is extremely important.

I am not sure there is a more fully featured meter at this price or lower which is the upside. The downside is that it uses a proprietary probe so you have no options when it comes time to replace it.