I’ve been messing around with the influence of ph in the finished product. It appears that most commercial beers are at or below 4.5 ph. I’ve measured a few that ive brought home. The SNPA that I measured was 4.3 ph (20ml sample with lid, sat till room temp) I think that if my mash and sparge ph is right, then it drops a couple more tenths in the boil, then a good healthy fermentation seems to get me to 4.5 or so.
For kicks I tracked my ph all the way through the APA I have on tap now. When I kegged it thee ph was 4.5. I was shooting for 4.3 so I could been cool like SNPA. So I had no idea how much 10% phosphoric to add. I took a guess and added 5 ml. After it was carbed up, I took another reading. I was also unsure how much carbonic acid would effect the ph. It didn’t effect it at all. The ph was still 4.5. So I added 20ml. Now its at 4.4 ph and I think I’ll leave it there. The difference in the glass between 4.5 and 4.4 is remarkable. The flavors are much more lively and the beer doesn’t have the slightly watery feel it had before. And im not detecting any off flavor from the acid, at least not in that moderately hoppy beer.
Anywho, ive heard and parroted the carbonic acid bite thing. Near as I can tell, 2-3 volumes of Co2 is not going to create enough carbonic acid to change beer ph. Apparently its a fairly week acid. It might drop low RA water several points, but it doesn’t drop beer much at all. At least my meter can’t detect it. I also have my doubts about carbonic acid flavor thresholds being such that its even detectable in beer ar 2-3 volumes CO2. My personal opinion is that what many are calling carbonic acid bite is actually just mouthfeel of CO2 coming out of solution.
At least I learned a ball park amount of 10% phosphoric to add in order to drop one tenth. Its a start.
+1 true as I understand it. weyermann has a decent slide deck on PH-mash to finished beer. the end of the deck is shameless pitch for their acidulated malt, but otherwise good overview.
Ive only tinkered with the final PH of my pilsner- getting it in the 4.4 range.
There are some German breweries that mash at a more typical 5.4 to 5.5 pH and then drop the kettle wort pH a couple of tenths. You have to believe that there is a good reason they do that. Jim’s result supports that. I’ve not tried that…yet.
the pils i referenced above was mashed in at 5.35 and then adjustments in the kettle for final PH of 4.4 in the keg. Jon just had a sample of it in our swap- I found it to be very crisp, refreshing and appealing.
might even mash higher PH in the 5.4-5.5 range next one and continue adjustments thereafter to my target of 4.4 finished product.
Very cool stuff, does this sound right to everyone?:
Mash: Ideally 5.4-5.6 for ideal conversion Kettle: Acidify to hit 5.2-5.4 in the boil to avoid harshness Kegged Beer: Acidify if needed to drop it below 4.5 for flavor and crispness, or to style specific targets (interesting that weyerman lists czech pils as ideally above 4.5)
could be. its somewhat variable the drop in PH after the boil, that results from fermentation and is specific to the yeast strain used for fermentation. PH drop from mash to end of boil may drop somewhere between.1-.3.
I’ve done this the other way with bicarb in a porter, but I’ve never thought to add acid to pale beers. I can think of a few beers that ended up a bit flabby and this may have been the missing piece. I will definitely be trying this in the future if needed. Thanks for sharing, Jim!
I thought I read something about some tests showing that wort pH and post fermentation pH are not necessarily positively correlated. But I’m not finding it at the moment.
Reading over a few posts I think we are talking about two different things. Natural ph changes and manually adjusting. I think that if you desire a lower ph in the final beer, starting with a lower mash ph may help. The drop in ph at the kettle occurs on its own, I assume through concentration and hopping. Then I think, as Ken says, the drop between kettle and glass is dependant on yeast strain and how healthy the fermentation goes.
My observation is that ph of the final beer plays a part in flavor and mouthfeel. But I don’t think it has the same effect on all beers. So a while back I measured ph of a sample of SNPA and Deschutes BBP. SNPA was 4.3 and BBP was 4.5 ph. Im using those numbers sort of like benchmarks. This APA I have on tap was significantly improved by manually adjusting it down just .1 ph. I decided to not add more acid just to go for the arbitrary 4.3 because 4.4 was awesome. So I’d likewise suggest to folks who might try this, don’t try to reduce it to a one size fits all method.
Also, I think with a little experience and maybe a carbing cap, a brewer could do this with bottle conditioning too. Its just more of a commitment to what you add or don’t add.
That Weyerman pH thing - I hope that list of beer style was referring to finished beer pH and not actually mash pH (even at mash temps).
Jim, I agree that with many beers adjusting the finished product with acid can help. The inverse is true, using a little bicarbonate in darker beers can seem to make them richer and maltier. That said - I approach this more like seasoning a dish than a hard and fast rule.
I’ve adjusted pH upward with bicarb for dark beers as well, with good results. But I’ve always resisted tinkering with lower pH until now - I think I’ll give it a shot. I always had the attitude that hitting mash pH spot on would carry over linearly to the final product, but that appears not to always be the case. Thanks for the info, Jim !
Depends on their mash temps. Limit dextrinase activity drops off above 145F. And while it’s peak activity is at 5.4 pH, it still is pretty active in the range from 5.0-5.8.