With 15 minutes left in my Grodziskie mash (100% oak smoked wheat), I realized I forgot to add the gypsum, CaCl2, and the citric acid that, according to the mash calculator at Brewer's Friend, would give me a mash pH of 5.5. Without said compounds, the mash was calculating to 5.8. So I quick measured them out and stirred them in. Before stirring them in, I pulled a refractometer sample from the wort at the top of the mash. It read 3.0 brix. I was expecting low, as this is going to be about a 1.030 beer, and as I do BIAB, all my liquid is in the mash tun, so it is dilute. After stirring in the chems and waiting 15 minutes, I checked again, and the refract read 5.0 brix. I was skeptical but decided to extend my mash for another 15 minutes, in case there was going to be more conversion. The refract readings stayed at 5.0 brix. I'm inclined to believe I made a mistake with my initial reading. At the time I didn't think to do a second one (which I decided to do to confirm subsequent readings). An alternate hypothesis is that there was a rapid effect of the change in mash chemistry to the sugar content. What say you? FWIW, when I'm done boiling, the 5.0 reading suggests I will be slightly shy of my target OG, but close enough. And my kitchen is apparently going to smell like a fireplace.
I think time was the more critical factor here than the pH. You say you measured the second time after an extra 15 minutes of mashing. At what point along the total mash timeline did you take your first and second (and third) Brix measurements?? EDIT: And of course you can always boil a little longer to compensate for the lower than desired gravity (or Brix).
Good question, and probably the answer. I discounted the time factor, and perhaps too quickly (because it felt like I've been mashing all day!). I was doing a multi-step mash, really for no good reason other than Gordon Strong does one in his published Grodziske recipe. Usually I do not bother. So that went like this, all temps in deg F: -Dough in at 104 for 30 min. -Protein rest at 124 for 40 min (I did 30 min). -Slowly ramp to 158, taking at least 20 minutes. I deviated from this again. I never really paid attention to how fast my electric BIAB might ramp from 124-158. At 10 minutes in, I was already at 152, so I held it at 152 for 20 minutes, then took it to 158. - Hold at 158 for 30 min. (I ended up holding for 45) - Mashout at 170 for 15 minutes (well, I went to 168, and only did 10). I was 15 minutes into the 158 hold, so the beer had been at saccharification temps for 25+ minutes when I took my first reading. Second readings were at the end of the 30 minute 158 hold, and third readings were after another 15 at 158.
Well there you go. I'm pretty sure it's purely a time thing. ...And say goodbye to your body and head retention (which would have been nil in a 1.020 beer anyway, but then given the long protein rest on top of that... egad... super watery thin).
I thought about that, but much of the info I can find calls for long protein rests for this style -Gordon Strong called for it in Modern Homebrew Recipes, - a BYO article called for a 30 min protein rest, -this style profile It may be that they all brewed crap beer and there is a reason the style almost went extinct, but I was banking on the hope that 100% wheat malt might demand a longer protein rest than we're used to seeing. Worst case scenario is I'm out 10 bucks in ingredients and a minor portion of a holiday weekend.
I only brewed one batch of Grodziskie and I conducted a step mash including acid & protein rests since a 100% wheat malt grain bill will provide 'extra' beta-glucans. That beer turned out great - not too watery or thin. Cheers!
@pweis909 send me a bottle and I will let you know what I think . Had several while in Poland, was hard pressed to find a bad one. Sure it will turn out fine.
Thanks for the generous offer. Most likely, this will end up in one of my 2.5 gallon kegs, not bottles.
It has been a while since I considered mash pH. In my quick search I do not see an appreciable difference between enzyme activity at 5.5 and 5.8. Anyone can feel free to steer me in the right direction. Without a pH meter reading there is no way to know actual vs. calculated. My guess is that the difference in brix readings are from stirring in the salt more than the salt themselves, like reaching homogeneity in the mash. Alot going on with the mash schedule. I would guess any deviation was dependent on that vs. any salt. Sounds like you hit the target OG anyway. Good luck.
We don't often talk about threshold effects in brewing, where a small nudge in one direction leads to very substantial impacts. I got caught up in the moment, thinking I had seen something very remarkable as a consequence of a nudge in mash chemistry, but more realistically, I was seeing an impact of time and temperature and, now that I think about it, possibly a sugar density gradient.
The Congress mash uses distilled water. That give the extract value we compare to. I can't remember how long they mash. Remember that Calcium is a cofactor for Alpha Amylase. Someone with more chemistry background than me may say if it speeds the process or not.
Good point on the cofactor; it does seem like it could have had more of an impact than I credited. My water, although not RO, had low calcium the last time i had it tested.
