It is said that the mash pH has a greater effect than temperature on the outcome, so it’s not surprising that I regularly measure the mash pH. The optimum value for infusion mashes is said to be at a pH of 5.40 whereas for decoction mashing some brewers select a slightly higher value of 5.50.
At boil many adjust the value to be in the range of 5.10 to 5.20 to ensure optimum hot-break and bilogical stability during fermentation.
That’s quite a lot to get right and I tend take qutie a measurements until the pH is in the correct range.
I’ve tried quite a few pH meters. From the cheap to the quite expensive. One I used for quite a bit is the Milwaukee MW101. Having worked with it for a good year, I found it rather tedious cooling down my samples to 25 Celsius. For an accurate reading this will remain the case, but for the various little readings one makes until the mash has the correct value I got a bit tired of cooling down the samples so that the electrodes won’t be damaged.
Enter the Extech PH110. The product is better supported in the UK and, albeit more expensive, it has quite a lot of features that make it ideal for brewing. It’s Automatic Temperature Compensation (ATC) has an operating range of 0-90 Celsius — which makes it ideal for measuring wort pH. I also like the fact that it’s a rather rugged design and dead easy to calibrate. One the probe is not accurate any more, the meter will signal that it needs to be swapped out.