Mash PH best practices

Hi all, my brother was asking me PH questions, and I realize I am fuzzy about certain things. So I have a few questions to help those of us who never really thought about PH in a practical sense:

1. Time
How long should I wait before taking a reading? Right after mashing-in, 10 min into mash, or 30 min?

2. Sample "location"
Where is the best spot to take sample from? Scoop out from the top? From the spigot?

3. Sample purity
How much grain/husk is acceptable in the sample?

4. Temperature
Room Temp? Mash Temp? Same temp as calibration solution?
(I understand room temp is best because it's better for the longevity of electrode and (even if I have ATC) the mash ph changes with temperature

5. Adjustments
Am I mostly looking to adjust for next time I brew this beer, or now?
(If now, after 30 min have gone by, what is the purpose? Conversion has already happened, no?)


Please feel free to add any other questions or comments, I'm looking to create a nice little cheat sheet for my brother while I re-read all Adjelandge's posts and finish the water book.


cheers

1. The enzymes start to work as soon as the grain is added to the water so you want to get your pH sample as quick as you can so you have an opportunity to adjust the pH for the majority of the mash.

2. If you stirred your grains in like you should have it when you doughed in, you will have a homogenous mix and it won't matter much where you take your sample except that you might get more liquid at the top.

3. I like to have mostly liquid.

4. I chill my sample to near room temp even though I have ATC on my meter too.

5. Your pH meter will give you a nearly instantaneous reading so you can make adjustments right away. Don't wait, conversion happens much quicker than most people believe. I use about a teaspoon of acid blend that my LHBS stocks and that brings my pH down to near perfect. YMMV

Thanks, this helps!

Mash pH can be adjusted before going to conversion rest. It's easier and less hectic than trying to make adjustments during conversion. The conversion rest shouldn't be started until the mash pH is appropriate. Infusion or bagger methods, mashing shouldn't begin if the pH is above 5.8. Optimum pH of alpha is 5.7, beta is 4.7, 5.3 is the center. Snakeroot salesman Charlie Tally made 5.2 stabilizer for a reason. I don't use it.

If you are interested in understanding what pH does. Pick up Noonans book on Lager. It's an easy to understand primer on mash acidification and what it does for the enzymes, yeast, etc., and the stages when it is performed. If you want more info buy Siebels book. Siebel goes deeper into what malts are more acidic and how water chemistry affects mash pH. Noonan packs it into about three pages. I use low modified floor malt, which has a better acidification quality than well modified. Phytase is killed off in well modified malt due to high kilning temp. It takes about two hours to lower mash pH to 5.1, using 10% sauer malt with 7.2 pH RO brewing water with some mineral adjustments. I do an acid rest at 100F. Once main mash hits 5.6, I pull the 1st decoction. By the time conversion is complete the entire mash is at 5.1. Then I begin sparge. I stop sparge at 5.8. I tri-decoction 15 to 20 gallon batches. I monitor pH right to the end of the sparge, during the boil and during fermentation. The pH will rise during the boil, but it has to be in the very narrow pH band for the type of yeast being used. After dumping trub and settling, Lager yeast pH band should be 5.3-5.5. Infusioned Ale, 5-5.2. Then add yeast. There's a lot more to brewing than dumping hot water on malt. Sometimes, RDWHAHB doesn't cut it.

Hi Vlad, thanks for the response. I actually have read Noonan's but will do it again now that I have a better understanding of water chemistry, malt, and PH.

I don't do decoctions (yet), and do only single infusion at sach. temps. (Ideally I would be doing double or triple decoctions and adjusting PH early on. However, I won't be doing that until I move out of my current setup.)

I'll report back once I've had a chance to brew again using the new PH meter early on.
I'll report

Make sure to do a test mash since this is a "first" time through. You could even do it the day before with a very small portion of the grain bill, carefully measured, and with any water adjustments you plan. I generally scale down to 1 lb of base malt, and reduce everything from there, including water and roast/crystal additions and BIAB this on the stove. I am sure there are other opinions on this...

After you calibrate the new pH meter (follow the manufacturer instructions) with fresh calibration solutions, then start the test mash (on your stove or wherever practical). You will quickly learn the reaction time of your pH meter. Mine is not instant and takes upwards of 30-45 seconds to settle correctly. I then rinse the probe with room temperature tap and store it in storage solution. Then check the test mash periodically, and make any acid/base adjustments to achieve your target mash pH. The first time through, I would recalibrate after the mash to see if it drifted. It is also helpful to do iodine tests to determine when you see conversion complete.

If you see the readings jumping all around, you may wish to replace the batteries.

Agreed on mash pH at room temperature. I use a couple of small nested stainless bowls, the bottom one with some ice to chill the sample down very quickly - use a thermometer to get it to room temp. If you have a lot of grain in the sample, filter it out as you transfer into a shot glass or other small vessel to test pH.

I tend to test immediately after dough in, assuming I haven't had to stir for 10 minutes. So generally, immediately, then at 5 minutes and again at 10 minutes. You should see only minor differences by the 10 minute point and have an idea if you need acid/base to adjust the pH accordingly. I tend to add half the calculated amount, wait a minute or two, then test, and if needed make the final addition.

Test location is a good point and I would think from the spout or manifold if you are using a cooler is a good idea, perhaps with a short vorlauf, if you can do it without losing temp. With my RIMS - I just pull from the top during recirculation.

Keeping good records of the times and readings will definitely inform and improve your adjustments for the next batch. However, remember that your grist ratio also drives mash pH and your adjustments will vary in that respect.

I'm just getting my eyes opened to the importance of checking raw water and mash pH and I really appreciate this thread. I don't have a pH tester and it is in the que for my next piece of brewing equipment. What pH tester do you use?

I just got this one:

Hanna Instruments HI98128

Have you read the thread at Bru'n Water?

https://sites.google.com/site/brunwater/

Yeah, I read that a while ago. The best read for water and PH (for me anyway) was the water book by Palmer.

But although I understand more and more about water and PH, somehow I missed the practical knowledge about PH meters and taking readings, hence my questions in the thread here.

Make sure to read the storage instructions, and take them seriously! You and your meter will get very close as you improve your water and mashing technique

I keep an extra bottle of storage solution as a rinse...

Haven't named it yet... Thinking Farrah or Tawny, but that just dates me.

Jboggeye said:

But although I understand more and more about water and PH, somehow I missed the practical knowledge about PH meters and taking readings, hence my questions in the thread here.

Click to expand...

I had scanned over the section on water quality in How to Brew. All those chemistry terms left me in a fog. Figured I'd come back to it later if it turned out to be important. Like you, that's why I'm here now. I'm now seeing how important it is.

mchrispen said:

Make sure to read the storage instructions, and take them seriously! You and your meter will get very close as you improve your water and mashing technique

Haven't named it yet... Thinking Farrah or Tawny, but that just dates me.

Click to expand...

Thanks for the tip. Are you using the Hanna tester also?

And it sounds as though my date sticker is pretty close to yours!

I used to have a Hanna I paid way too much for and destroyed trying to take hot measurements. I abused that poor thing and it lasted me maybe 6 months. I still wonder if I ever got a correct reading. That said - I thought I knew what I was doing - and didn't.

This round I bought a Milwaukee with a replaceable probe, manual calibration and no ATC. I have been very happy with it - and now, of course, store it properly and use it properly. Revisiting how I take pH and making it a more ritual in my mashing process has been very helpful. FYI - calibration has not drifted much at all over the past year and half with the Milwaukee, to the extent I wonder if I am measuring drift in my calibration solutions. I replace those about every 6 months - they are cheap enough.

mchrispen said:

This round I bought a Milwaukee with a replaceable probe, manual calibration and no ATC. I have been very happy with it - and now, of course, store it properly and use it properly.

Click to expand...

Is yours the MW100?

Yeah... was right in the butter zone for price/performance and features - and similar to a probe I used 25 years ago in college. Not saying it is the best pH meter... not qualified to make a statement like that. I think the pen styled probes are probably pretty good - everything seems to get better and smaller these days. I would have to defer to the experts on that side of things.

Personally - I think that as long as your maintenance and calibration routine are consistent and you catalog your readings appropriately, any reasonable meter will work great. For me - this is more about disciplined application and making very small adjustments along the way to tweak something. This process (along with better water chemistry) has dramatically changed my end products for the better. Do keep spare batteries around! They are cheap in bulk on Amazon.

The Bru n' Water spreadsheet from Martin will do a very good job of predicting your mash pH given your water chem and grain bill. I have found it very accurate compared to my actual measurements.

Dough in should be sufficient to thoroughly wet the grains and allow them to do their buffering. I recirc (RIMS) and take my reading after dough in and within a couple minutes of starting my recirc.

If you use an ATC probe you should try to take your measurements as close to your calibration temperature as possible.

mchrispen said:

I would have to defer to the experts on that side of things.

Click to expand...

Have to be careful calling someone an expert, you know? After all, that word is a two-part engineering term:

ex = has-been
spurt = some drip under a lot of pressure

Thanks for the tips Bud!
:cross:

As far as I can tell, the mash ph is mostly important for conversion and preventing tannin extraction. You can be above optimal ph without much negative effect on the wort production.

What is important about ph is more in the boil. Higher ph in the boil will lead to harsher hop bitterness and more color change. I think it might also contribute to a higher finishing ph, which gives the resulting beer a more dull flavor.

Since I've started adjusting my ph, my bitterness is smoother and my beer tastes brighter but the wort I produce is the same as it ever was.