I thought about this when I was mashing my Porter earlier today. I took an initial sample to test my ph maybe 8-10 into the mash once I was all stirred in well and happy with my temps. The first cooled sample had a room temp reading of 5.75 so my actual mash ph was about 5.4. I took another sample with about 10 mins left in the mash just to see what it was then and my cooled sample gave my meter a reading of 5.7 so that’s about 5.4 in the mash. I’m guessing the reading changed slightly with more time to allow the reactions to take place, but it wasn’t much enough to worry about. It also could have been just a slight difference in the room temperature sample I pulled from the mash the 2nd time. Temps would have to be exact when measured to really be relevant. But in the end, not enough difference to worry about and no more than 10 mins into the mash seems to be plenty of time for reliable reading.
The cooled sample is what you base the the reading on.
^^^…Could you elaberate?
Your mash pH was 5.7, not 5.4. The pH is always measured at room temperature. 5.7 is at the high end but no worries, it should be just fine.
5.7 at 70* or so… 5.4 in the mash at 150 degrees plus. Correct?
Roundabouts, yes. But the texts that talk of optimal mash pH are referring to a cooled mash sample, so it doesn’t really matter what the heated mash pH is. That would only be useful if you were reading the hot mash temp, and that will damage your probe (been there, done that).
I see a lot of mixed info of how ph is talked about which seems to cause confusion. I always understood we needed to factor in the .3 of ph difference when we measured our cooled sample. If this is not the case, I have been doing it wrong all this time. When I read or hear talk of mash ph, I understood it as the ph at mash temps. So in turn when I use water calculators to estimate mash ph I understand that was for a cooled room temp sample, but I always shot for .3 higher with the undersanding the true ph in the mash would be .3 lower. Sounds like I’ve been running my mash ph to high?
Wow, talk about a light bulb going off. No wonder I was always so confused, I confused my damn self. I failed to realize the “ideal ranges” often indicated were/are for cooled samples. Damn, well I appreciate the info to help set me straight. I guess at least with this last batch, being a nice big Porter a mash ph of 5.7 isn’t too bad considering all the talk lately of higher mash ph’s for darker beers like these. Moving forward I’m no curious to taste improvement in my beers because of this.
It was bedtime for me, 6 hour difference. Just back on. JT has summed it up. The Texts say the pH is for the room temperature measurement. Martin has talked about this, along with others.
Whenever I deal with pH the numbers are at 70F. Targets, actual, mash, preboil, post boil, final in the glass. It leaves out the math.
Maybe a bit, but you’re still within range for conversion. The big risk if you you start high like is that it will likely climb higher when sparging and that can extract some tannins that you probably don’t want in your beer. This risk is reduced a bit if you batch sparge and/or use reverse osmosis or distilled sparge water.
There is still a BIG gap in my own understanding as to how pH plays a role in all the various stages of the process. The list includes, but is not limited to conversion in the mash, hop utilization in the boil, flavor stability post fermentation, taste when packaging, etc. There are many on the forum tinkering with this now. Good stuff.
Time to get up and turn on the HLT. Cheers!
Thank you guys. This is why I came here, to read over posts and pick the brains of everyone here. Now that I look back over things I have read before, I can see it plain as day but at the time I interpreted it all differetly.
Well, if my mash ph’s have been running high becasue of this it goes for everything in my process like sparge ph, pre and post boil ph…etc because I was treating them the same as my mash ph in regards to the .3 ph difference. So sparge ph and boil ph’s have also been running high. Only thing I have treated as a room temp reading has been finished beer ph…(which has been higher on some beers).
I guess this explains whey I always felt my best beers have been darker styles…Stouts, Porters, Browns. That would be because they can handle a higher mash ph. Other styles I brew are bound to have improvement going forward. Now I’m excited to brew the next batch and fix this mis-understanding. Thanks again guys, might seem like it’s no biggie but that could have a huge impact in my beers.
It matters. If you don’t believe me, come down to central TX and try to brew a non-dark beer with the tap water (even dechlorinated) - I’ve got solid limestone bedrock less than three feet from topsoil on my property (alkaline city). Flabby, weak, lifeless are all descriptors of those lighter style beers before I got a handle on my water (by switching to all RO), using some water calculation software (Bru’n Water is great) and measuring mash pH (at room temperature!!!).
Consequently, the only good beer I produced when I first started and had no knowledge of the importance of brewing water was stout. Go figure.
When I started focusing on light colored lagers, same story,