Where to take your mash pH sample
Does it matter from where in the mash you draw your pH sample?
Maybe also interesting for BIAB-brewers
I decided to give this mash pH experiment a shot during a normal brew day?
So it was a typical brew day ( as if there’s any, right? ). My strike water was up to 69C or 156f, 5 degrees Celcius or 9 degrees Fahrenheit over my planned mash in temp at 64C or 147f. I’ve found out that its work excellent for me as the grains cool down the strike water quite a bit. After adding my grains to the strike water, I gave it a gentle but good stir. Not to aerate the mash more than I needed. I always give it another gentle stir at around 15-20min in the mash. It’s at that time I usually take my first mash pH reading.
I took one sample in the mash and the other outside of the grain pipe
What I usually do is at 15-20 minute, is to lift up my recirculating hose from the top of the grains and fill a small amount o wort in a small glass. But that is drawn from the bottle of the kettle and not from the mash itself. Is there a difference. This would compare to as if a BIAB brewer who would take there mash pH outside of the bag in the kettle. It never actually bothered me even to give this a second thought before. But the other day it got me starting to think. Fifteen minutes into the mash. It might be a great difference between the mash pH in the mash and in the wort outside oft the mash if your grain pipe or all in one brewing system. So to find out little more about this topic, I took one sample in the mash and one outside of the grain- pipe. Think of it as one pH sample drawn from the bag and one outside of the BIAB bag if you’re a brew in a bag brewer.
My two mash pH samples, one from the mash and one from the pump.
Two samples were taken at the same time from two different spots
My two samples, one from the mash and one from the pump. Pumping wort from the bottom of the kettle outside of the grain pipe, and the other one straight from the mash with grain and all. I placed both of the samples in cold water to take the temperature down to about 20c or 68f. Room temp. Even if I have a really good pH meter that can calibrate for different temperature. I want to stick as close to the room temp temperature as possible. Just to be certain. Don’t really trust the calibrations that much. And cooling down a small sample of wort doesn’t take that long. But as this is an experiment, I chose to go the extra mile. After cooling the wort pH samples down in cold water, I’ve let the two samples of wort stand in room temp for an hour to equal them self out in temperature. I decided to leave the samples an hour at room temp.
Okay, time to take the pH-meter out
After an hour at room temp ( just to be anal ). Both samples had the exact same temperature. If I were going to do this, I better do it right. Right? My Ph-meter is very good. I like it for its price and I found it to be not only very accurate but also very stable over time. If you’re after a pH meter, check it out. ph55 – link to pH-meter–> I’ve had it for quite a time now. I did calibrate the pH-meter when I got it new and shiny straight of the box. Or more like the tube, it came in. Pro-tip, don’t through away the tube pH-meter came in. You want to store it in the container it came in as the pH-meter itself can’t stand upright. The ph-meters tip needs to be stored in a storage solution. I will link to meter, storage solution, and calibrations solution also at the end of the post. Storing the pH55 upright saves on storage solution and thereby also save money. The pH-55, like most other pH-meters, does take some time to adjust to the pH of the liquid, and for you to take a stable reading. There’s an hourglass icon you have to wait for, and it can take some time. As you see in the YouTube documentation video, I made of this experiment.
Tip of the day: don’t throw away the cylinder it came in.
Does it matter from where in the mash you take the pH samples
After going back and forth a lot of times. Just to be entirely sure, as I wasn’t getting the same reading. As seen in the video. I did, in the end, find a small but maybe insignificant difference between the two samples ph. But as little as a pH difference as pH0.1. The pH55 has only one decimal so I couldn’t get any more accurate reading than that. There’s a lot of cheaper pH-meters than the pH55 to be bought with two decimals from various “no-name” providers. But I wouldn’t have trusted them as much anyway — you kind of get what you pay for with this kind of things. If you want to get a more exact and faster pH-meter than this one, you need to cough up a lot more money. And for homebrewing, I can’t see the point of that. But if you’re making blog posts about it maybe. LOL!
I’m not going to worry about it
My conclusion of this little mash pH experiment is that it doesn’t seem to matter so much where you take the sample. I’m not stressed about 0.1 difference in pH. I used to use pH-strips for quite a while before I invested in the pH55. I have a video on another mash experiment I did with pH-strips on my YouTube channel. Ph-strips and temperature in brewing–>
Go and check that video out if you’re wondering if the pH reading is affected by temperature when measuring pH with pH-strips. As for my next mash experiment, I will try to find out at what time we should take the mash pH measurement. In this experiment, I chose to take the pH sample of wort at 15min into the mash. But maybe time is a more significant factor than were. Sign up at my mailing list to get updated when I release a new post or video. And you will also get my ebook for free. Three of my best recipes in a compact format.
Cheers and thanks for checking out my blog. See you in the next one, DrHans out!
Don’t think I ever spent so much time on pH during a brew day. I guess it will take even more time in my next pH mash experiment. Don’t forget to sign up on my mailing list, so you don’t miss it. And you also get my free ebook as a bonus!