Gordon Strong adds to the whole ph/temp saga

[wildwest450]

Just reading through Brewing Better Beer and this is his take on mash ph temps.

He suggests a target of 5.3 (nothing new there), but that's AT mash temp. He say's to add .3 if you check at room temp. So should we be shooting for 5.6- 5.7 at room temp (68f)?

I was under the impression that you wanted 5.2-5.5 at room temp. I should have never bought this book.

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[MNDan]

Between 5.5 and 5.8 @ Room Temp has always been the standard I believe.

 

[wildwest450]

I guess my real question, does Ez water calculator take the .3 into account?

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[BioBeing]

The pH of the mash is what matters. It should be around 5.3.

However, pH varies with temperature. So, if you measure the pH at room temperature, it is going to be different to what it was when it was at 150F. So, yeah, you need a correction factor.

 

[ajdelange]

In my experience (and I haven't measured it many times because it is hard on electrodes) the slope with temperature is 0.0052 - 0.0057 pH/°C. This is for very soft water and pilsner base malt beer. DeClerck presents results that show the shift is dependent to some extent on water chemistry (makes sens - the more alkaline the water the more the shift is going to depend on the temperature-pK behaviour of carbonate and the less alkaline the water the more it will depend on the temp-pK behavour of phosphate).

Using the numbers I observe if you call room temp 21 °C and dough in at say 41 °C (acid rest) you would have a pH shift of about 0.11. If you dough in at, or check at 52 °C (protein rest) you would have a shift of about 0.17 and if you check at 66 °C (saccharification temp) about 0.25.

Based on this it is clear that a fixed shift of 0.3 isn't going to cut it. More important than this is that all modern literature specifies pH at lab temperature. In the older sources you can only guess as to whether they are talking about lab or mash temperature though DeClerck does specifically state that all pH values in his book are at lab temperature. Anything dating from DeClerck's time or before is doubtless lab temperature as a pH meter didn't fit in ones shirt pocket in those days.

As to what is the optimum pH - that varies. I attended a conference in Belgium in which 3 days was spent on "The pH Paradox" (the title of the meeting) with the paradox being, in case anyone has not figured it out, what the "optimum" pH is. Whenever you see the word "optimum" you should ask "What's your optimality criterion?". As there are, in fact, several when it comes to beer it should not be surprising that there is a "paradox".

In my own brewing (lagers, German ales) I found that beers brewed at room temperature mash pH 5.4 - 5.5 are dramatically better than ones brewed at 5.6 or above. Note that Kunze states that the optimum pH is 5.5 - 5.6. Doubtless his optimality criterion is somewhat different from mine. I'm not saying that the right answer is 5.4. If all those heavyweights in Belgium couldn't figure it out I don't have the temerity to claim that I have. 5.4 is just what works for me.

I do advise people to treat their water and mash such that they should come out with pH in the 5.4 - 5.5 range and I've had several reports of dramatically better beer from several who followed that guidance with the phrase "brighter flavors" being the best description of what I noticed when I got strict about hitting that range. Those are not my words - I wish they were as they are very apt. I have yet to see a complaint that my advice ruined a beer but life being the way it is expect to eventually.

 

[-TH-]

I guess my real question, does Ez water calculator take the .3 into account?

_

I recently revised the notations on EZ to make it more clear that the estimated pH is at room-temp. I also revised the desired range, although as AJ has demonstrated there are varying opinions on that and you may want to determine your own.

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[sv_1]

What is the proper technique for sampling? Do you take a small sample so it cools quick enough to leave time for adjustments? Do you start timing the rest after adjusting to proper ph range?

 

[ajdelange]

There are several ways to do it. I dip a small quantity of the mash using a very small saucepan (which I swiped from Mrs) and then set that in a sink with a small amount of cold water and it cools pretty quickly but it does take some time. Things you use to adjust take some time to mix into the mash and some time to react so that a few cycles of measure, add, wait, measure again are going to put appreciable time on the clock and it is clear that mash pH will not be correct during that time. I guess you can argue that if mash pH is too low the enzymes are not working at their peak efficiency but that as long as you get pH into the right range they should come to peak efficiency and do the job on the substrate they were not attacking optimally at the outset. This reasoning bothers me a little. It certainly doesn't apply to temperature as an excessively high temperature could denature an enzyme irreparably.

Thus it is best that the mash pH measurement be a check of a pH you are confident will be close to what you want. The best way to be sure where pH is going is to do a test mash - a small portion of the grist in a proportionate amount of the water you are going to mash with in a glass in a water bath or in any arrangement which holds it at approximately the right temperature. Check the pH of that. If it is too low add some chalk or lime until, after a suitable wait, it is correct. If it is too high, add some more acid or sauemalz. Again, wait and measure. Now scale the amount of corrective substance to the full mash size and go ahead and dough in. You probably won't be spot on and that is OK. Next time add more or less sauermalz or chalk accordingly as to whether the full mash pH was too high or too low. Eventually you will zero in on the right additions and the mashtun check becomes no more than that - a check.

If, in the mash measurement, you wind up with a reading that is way off base then you should, of course, try to correct it in the mash tun. While this is not desirable it is, of course, better than ruining the beer.