I am still new to brewing: First attempt with Christmas gifts used a refill kit that turned out to be partial - resulted in stout that tasted fine but is very weak. Second attempt is due to be bottled later this morning. This second attempt is a "North of England" brown ale LME / grain kit.

I've been reading quite a bit from John Palmer's "How to Brew" which seems to be a pretty complete guide, and I'm reading a lot about water. I've managed to get the local water reports (Irving,TX - water supplied via Dallas). Using the calculators inside the back of the book, I'm coming up with a mash pH of 5.7-5.8. This seemed a good match for a brown ale.

I measured the mash with brewing pH strips (as I'm starting out, I'm wary of investing in too much expensive equipment upfront - I can get a pH meter later if necessary). Okay pH strips aren't the most accurate, but I came up with a result more in the 5 - possibly 5.4 range. This is way off the bottom of the scale in the book!

I guess my question is, is it possible the mash was really that low? Or are the papers really that inaccurate? Of course the mash was a brown colour (as were the indicator colours), and the papers have a 0.4 resolution in the scale indicator. Could mash temperature have influenced the reading?

If it helps, the kit was 50/50 Amber and Dark malts with speciality grains mostly Caramel (3/4th) and lesser (1/8ths) special B and chocolate.

Looking forwards, I plan to brew quite a few English porters (a type of beer I like), but will not start these until Autumn (however much I like a good porter, they're not for a Texas summer!). I'm assuming I should adjust the chemistry for these? Before that, I intend to brew paler beers - I've just ordered an ESB kit, and after that I was thinking of more of a summer pale ale.

  • Was this a primarily malt extract recipe with steeped specialty grains?
    – Grafton C.
    Commented Feb 24, 2015 at 0:51
  • Yes - see my second to last paragraph. Liquid malts with steeped grains.
    – winwaed
    Commented Feb 24, 2015 at 18:24

2 Answers 2


Your pH was right on.

The optimal range for alpha- and beta-amylase is 5.1 to 5.5. See the "mash target" bubble in this image from How To Brew.

Mash pH, Temperature & Enzyme Activity

  • 1
    Always worth noting that mash pH depends on temperature. At mashing temps (~150 F) pH is typically ~0.35 units lower (more acidic) than the same mash cooled to room temperature. Commented Feb 21, 2015 at 18:58
  • @Franklin: I bet that is what is going on, because the diagram in the inside back cover with the colour guide that I was using suggested a higher pH. The difference is going to be about ~0.35... Explains my potential confusion :-)
    – winwaed
    Commented Feb 21, 2015 at 19:53
  • I should say I'm not positive how this effects a reading on a strip, only an electrode-style pH meter, since strips will probably cool well before you read them. Commented Feb 21, 2015 at 20:28
  • I left out temperature effects because I didn't know if it applied to strips and such a small sample should cool pretty quickly. Commented Feb 22, 2015 at 15:34
  • Further, there are two temperature effects. 1. As noted by @FranklinPCombs, pH of the liquid at mash temp will be lower than the same room temperature sample. 2. High temperature changes the way electrode-based pH meters read. Auto Temperature Correcting (ATC) meters correct for this phenomenon, but not the first effect. Commented Feb 22, 2015 at 15:39

If the vast majority of your fermentables are coming from extract, pH isn't something you need to worry about. pH and heat are extremely important factors for mashing, but if you're using extract and specialty grains, you're not really mashing in the same sense. When you actually do start AG brewing you'll find that the grain addition tends to drop the pH to that sweet spot area anyway, barring something really wrong with water treatment. (Not sure how DFW does it, but all my mashes in Austin were spot-on without treatment.)

  • Thanks - and the dissolved ions, Ca, Mg, HCO3, etc? My understanding is that different concentrations favour different beer types?
    – winwaed
    Commented Feb 25, 2015 at 13:33
  • 1
    Water chemistry is crucial when attempting to reproduce or build around a classic beer style, e.g. using Berlin's water profile to brew a Berliner weisse, or cloning a commercial beer from another area. I don't mean to discourage you from experimenting with water chemistry, but the return will probably not justify the effort at this stage.
    – Grafton C.
    Commented Feb 25, 2015 at 21:42
  • @winwaed, different ions play different roles in the process. Ca and Mg are hardness ions and will tend to lower wort pH (even with extract) by reacting with malt-derived phosphates, while HCO3 (bicarbonate) buffers (works against) acidification. The three play a much larger role in all-grain brewing, during the mashing phase. Ca and Mg are also important yeast nutrients. Other ions, like SO4, Cl2, Na, etc. are, comparatively, chemically insignificant, but do provide distinct flavor characteristics in the finished beer. Commented Feb 26, 2015 at 0:08
  • Okay taco & Franklin - I'll "put a pin in it" until later :-)
    – winwaed
    Commented Feb 26, 2015 at 13:42

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