I thought we were supposed to take a mash pH reading at room temp. I actually thought, even with pH meter with ATC, we’re still supposed to have sample at room temp. This normally means taking a small sample of the mash and cooling, as quickly as possible, the sample to room temp to take the pH reading.
However, I recently found a stack of BYO magazines that I had misplaced. Reading thru the December 2017 issue a number of folks wrote into the magazine to question/complain about October 2017 “Help Me, Mr. Wizard” column stating to measure the mash pH at mash temp.
The wizard’s answer in the December 2017 was, at least to me confusing. IMO, his answers normally ramble on way too much. For example, ask “Is today Sunday” and instead of getting a yes/no answer, he’ll walk thru each day of the year, each month of the year, talk about the different calendar systems invented by mankind, etc before, hopefully, finally answering the question.
What do others do regarding taking mash pH. Cool the mash sample to room temp or plunge the pH probe into the mash?
I’m an odd duck, but after many hours looking into mash pH after reading the same Mr. Wizard columns and forum threads like the ones linked below… for many years I have been measuring at MASH temp and aim for about 5.3 to 5.35, which at room temp would be about 5.55 to 5.6. I’ve compared measurements at both temperatures and found the difference to be about 0.25. Some report a difference as low as 0.18 to 0.22, some report up to 0.3, but it’s in that ballpark.
As long as you understand that you need to mash at 5.3-ish as measured at MASH temperature, or about 5.55 to 5.6 at ROOM temperature, then it doesn’t really matter which temperature you measure at. The problem is, millions of brewers are aiming for 5.3 as measured at room temperature, and that’s inappropriate, because actual mash pH then is very low around 5.0 to 5.05! Not what anyone really wanted at all!
Forget whatever you think about ATC. It’s essentially useless, and misinterpreted by millions. The actual pH changes based on temperature, and ATC does NOT account for that. It just doesn’t! It’s so misunderstood. Just like the pH range goals are sorely misunderstood.
Rabbit holes:
All that being said… can you still make great beer mashing at 5.0? Obviously yes you can! But… is it optimal?? Well I dunno. I can tell you this: my brewhouse efficiency continues to creep toward 90% average every few years until I open up the gap on my mill again. Coincidence? I dunno.
This is the best advice you can get. The bottom line is that when you measure pH at mash temperature, the probe needs to be rated for that temperature. If you use the standard Milwaukee probe, etc., you will shorten the life of the probe. ATC has to do with calibration over a wide temperature, it does not correct for varied pH readings over temperature. As the temperature rises, the pH drops. So the target pH at room temperature is as Dave said, @ 5.6.
This seems to pop up every cpls years and like this, it gets confusing. What temp, what pH target, when to take a sample, what estimation tool …. Age old HomeBrew questions.
My recommendation: Choose your process and stick with it over time. If you keep switching back and forth between any of the variables, advocates for certain processes, or estimation tools, you will get different results which will simply cause more confusion and prompt more questions. Most importantly: Taste the finished beer and see if you like it. If you do, stick with it. If you don’t, change it. You’re the brewer; it’s your beer. Whatever you do, don’t change simply because someone on the internet in a book or magazine says you’re doing it wrong
After all the articles and books, spirited debate, and deep contemplation, here’s where I landed: After I enter all my recipe information in the BeerSmith Design tab, I use the Water tab to enter my water sample results from Ward labs and determine salt additions. Then I use the Mash tab to estimate pH and estimate acid additions (if required). I calibrate my pH meter using new pouches of pH sample standard solutions stored at room temp prior to measuring a mash sample. I collect strike water and use a TDS meter as an indicator to determine if my water filters are still at my baseline sample I sent to Ward labs. After I deoxygenate the strike water, I add CaCl and gypsum together to strike water. Then, I add sodium bicarbonate (if required) separately to strike water. Last I add Brewtan B. I use 85% Food Grade Phosphoric acid as my acid of choice (if required) that I add to the mash after mash in. I recirculate during the entire mash and take my official mash sample at 45 min. I target 5.3-5.4 Lite color beers, 5.4-5.5 Amber/lite brown beers, 5.5-5.6 Dark beers using samples cooled to room temp. I clean my pH probe after every brewday using a new pouch of cleaning solution and store it in storage solution.
I use competition results from the larger HomeBrew competitions that attract the best judges as a feedback loop. I pay particular attention to National or higher ranked judge’s comments. I’ve been very pleased with the beers I brew using this approach and oftentimes, judges agree.
There are pH probes that are rated for relatively high temperature use, but they are intended for use in an industrial process that is run for long periods and the probe is kept at high temperature for most of its life. Going from room temperature into hot wort is NOT the setting that the probe manufacturer is accommodating. Understand that the probe has a very thin glass bulb and heating and cooling that bulb is eventually going to fail the probe.
Be smart, always check your wort pH at room-temperature. I use a stainless steel shot glass to hold my hot wort and I swirl the ‘glass’ in an ice bath and monitor the wort temperature with a thermometer and pull the glass out of the bath when the temp gets close to the mid-60F target. It typically takes me less than a minute to chill my samples this way.
Yes, I too use the shotglass sample cooled to room temp. After reading the BYO “Mr. Wizard” reply I was wondering if I fell into the “repeat it enough and it becomes the truth” situation.