Wort and Beer pH

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Mateo

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I was wondering if anyone could point me to some reading regarding the pH of certain worts and certain beers.

I have searched but found very little out there. Perhaps I am searching wrong.

m.
 
There are some advanced books that cover pH ranges but I'm not aware of any online resources. Unfermented wort is 5.0 - 5.5 and fermented beer is 4 - 4.5.

Do you have a specific question?
 
This is an area of brewing that is new to me and I am starting to delve into it. I would like to know what other's research has yielded.

I brew primarily very light colored lagers with very soft water and thus it has propelled me in the direction of researching pH and its affect on the final product.

I have been testing the lagers that I like and most of them are very low pH. I have brewed a few beers prior to paying much attention to pH and found them to be very high in comparison to the commercial lagers. This prompted me to dig deeper.

There seems to be a subtle complexity to the beers with slightly lower pH readings and those with higher pH readings seem to be simpler.

I did read that Ales tend to have lower pH than Lagers. Is this correct?
 
I brew primarily very light colored lagers with very soft water and thus it has propelled me in the direction of researching pH and its affect on the final product.

That's step one for a successful lager. Step 2 is to use acid (sauermalz) to set the pH between 5.2 and 5.5.

I have been testing the lagers that I like and most of them are very low pH. I have brewed a few beers prior to paying much attention to pH and found them to be very high in comparison to the commercial lagers. This prompted me to dig deeper.

That's because commercial brewers (not all but most) control wort pH. Get that right and the beer will fall into place.

There seems to be a subtle complexity to the beers with slightly lower pH readings and those with higher pH readings seem to be simpler.

That, in few words, is the secret to lager beer. One fellow who saw the light described it in terms of all the flavors being brighter.


I did read that Ales tend to have lower pH than Lagers. Is this correct?

Yes, in general. Here's what I found in my logbook for my last few brews:

Kölsch: 5.16 --> 4.41
Pils: 5.17 --> 4.53
Weizen: 5.22 --> 4.03
Märzen: 5.26 --> 4.40
Bock: 5.08 --> 4.59

with the value on the left being the value just after pitching and the number on the right the pH in the fermenter close to or at the end of fermentation. All these were brewed with soft water and sauermalz.

OTOH the new brewpub in town does not use sauermalz nor check pH during the brewing process. His last Alt came in at pH 4.45 and a Kölsch at 4.40. Both very good beers.
 
I'll add that beer with a pH closer to 4 has a sharper, more defined flavor than a beer closer to 4.5 due to the additional acidity and its interplay with other flavor compounds.

However, beers closer to 4.5 are more flavor stable for a longer period of time. There is always a trade off. ;)

Also, sour beers are typically below 4 due to the lactic and acetic acid.
 
Once I began measuring pH I first measured a pils at mash-in with a pH of 5.8, I did nothing to adjust the pH and the beer came out decent. It was well received and did not last long. The following beer I used an extended acid rest and the mash-in was 5.1 and the wort measured slightly lower. This beer is still lagering and I am not sure what the final pH will be. I brewed a subsequent Export Hell which I added 3 oz. of sauermalz to the grist and the pH was 5.3 at mash-in. This beer is also still lagering, however I sampled a taste of it and it has the potential to be my best beer yet.

I have two other helles that are fermenting that I used acid rests on for 30 minutes and 1 hour respectively. Both of these mashed-in at 5.2 pH.

When measuring wort or beer to you calculate for temperature? Or degas the beer?
 
Also, sour beers are typically below 4 due to the lactic and acetic acid.

Yes, but note that the Weizen (an ale) almost busted 4 (4.03) and some British ales have pH < 4

However, beers closer to 4.5 are more flavor stable for a longer period of time. There is always a trade off. ;)

The de Clerck Chair is a multi day conference of brewers sponsored jointly by the Waloonian and Flemish manifestations of the Catholic University of Louvain. Chair XI was entitled "The pH Paradox" and dealt with those trades.


Mateo said:
The following beer I used an extended acid rest and the mash-in was 5.1 and the wort measured slightly lower.

Tell me more about this. If "extended" means a couple of days at elevated temperature I can see malt lactobacilli going to town and producing enough lactic acid to get you to 5.1 (sour mash) but I can't see anything like this happening in a few hours.

Mateo said:
When measuring wort or beer to you calculate for temperature? Or degas the beer?

The sample is just placed in a small cup, placed on the bench and the measurement taken. Because the volume is small it is warmed somewhat by the time the electrode is inserted (and that,of course, tends to warm it some too). I also wait a while so that the meter bulb doesn't get covered with CO2 bubbles and a stir to sweep whatever do form off. But no formal warming or decarbonation step. If it's a check on fermenting beer it's the remainder of the hydrometer sample which has been well shaken so the hydrometer can be used.

So what's the effect of temperature and pH? I just drew a sample of Pils and checked the pH: 4.48 @ 5.5 °C. I let it warm to 10.1 °C at which time the pH measured 4.49. With vigorous swirling/sloshing the pH rose to 4.55 - this would be the effect of departing CO2. As the beer warmed further the pH fell back a bit to 4.54 and stayed there up to 17.6 °C which was reached over an hour later.
 
Yes, but note that the Weizen (an ale) almost busted 4 (4.03) and some British ales have pH < 4

Which helps explain why so many imported English ales taste rancid and/or oxidized by the time they make it to your glass in the states. :(
 
I have 4 experimental batches brewing.

The first I purchased 1 extra pound of grain and mashed it in a igloo cooler by itself. I put it in at about 95F and measured the pH every hour and recorded its changes. Initial pH was about 5.8 and over the course of 5 or 6 hours it dropped to about 5.1. So using this principal I mashed 50% of my grain at 95F over night. Mashed in at 95F around 7pm and recommenced at about 6am. The mash pH had dropped from 5.8 to 4.7 over night. I added the rest of the grain and the mash stabilized at about 5.1 to 5.2. Once the mash was finished I could detect a distinct affect of the acid rest. It was quite pleasant, however I do not yet know its final effect on the beer as it is lagering. I measured around 4.8 after the boil was complete.

The next batch I used 3 oz. of sauermalz. This was straight to the protein rest and on to full mash temps. This one was mashed with an enhanced decoction and mashed in at 5.3 or so with the saurmalz. It is currently lagering.

The next batch I used an acid rest at 95 for about 1 hour or slightly more. This mash was at about 5.4 pH after the acid rest. It started around 5.7. I did not accurately measure the time and it could have been a bit longer. This mash was allowed to sit at 150F overnight. The following day the mash was just below 5. Perhaps in the 4.8 to 4.9 range. This beer is lagering.

The last beer I used a fairly short acid rest at about 30 minutes as the mash-in pH was 5.2 due to an adjustment in the brewing salts. I allowed this one to sit over night at 150F and it was below 5 in the am. This beer is lagering as well.
 
I believe both "How to Brew" by John Palmer and "Designing Great Beers" by Ray Daniels cover pH in some detail. Good books to have on hand either way :mug:
 
I put it in at about 95F and measured the pH every hour and recorded its changes. Initial pH was about 5.8 and over the course of 5 or 6 hours it dropped to about 5.1. So using this principal I mashed 50% of my grain at 95F over night. Mashed in at 95F around 7pm and recommenced at about 6am. The mash pH had dropped from 5.8 to 4.7 over night.

Interesting - faster than I thought it would be. When I made some sauermalz I left it in the incubator for a couple of days but there was plenty going on the second day (don't think I measured pH but it was bubbling). And when I make sourdough pizza I only leave the sponge in the incubator over night.
 
I believe both "How to Brew" by John Palmer and "Designing Great Beers" by Ray Daniels cover pH in some detail. Good books to have on hand either way :mug:

I have not read these two texts, however, I suspect that most the preoccupation is with mash pH and not wort or final product pH, which is suspect has a direct correlation to the mash pH, and the mashing/brewing techniques used to produce the beer.
 
Interesting - faster than I thought it would be. When I made some sauermalz I left it in the incubator for a couple of days but there was plenty going on the second day (don't think I measured pH but it was bubbling). And when I make sourdough pizza I only leave the sponge in the incubator over night.

AJ

I am under the assumption that you are referring to the duration needed to incubate and develop a significant amount of acidification via lactose bacilli fermentation, which occurs after only after several hours. During the first few hours any acid produced must be attributed phytase activity. While it may be weak, it still can have significant affect on the mash pH.
 
AJ

I am under the assumption that you are referring to the duration needed to incubate and develop a significant amount of acidification via lactose bacilli fermentation, which occurs after only after several hours. During the first few hours any acid produced must be attributed phytase activity. While it may be weak, it still can have significant affect on the mash pH.

Yes, absolutely. Examination of the liquid showed it rich with lactobacilli (or rods of some description).

I can't remember whether I used tap, RO or DI water but in any case there probably wouldn't be a drop from phytase because:

1) this was higher kilned malt - phytase is inactivated at fairly low temperature
2)Incubation was at 57 °C which is ideal for lacto's but again I think high enough to denature phytase.
3)The phytase catalyzed reaction involves the precipitation of hydroxylapatite with calcium. There is no calcium in DI water and very little in RO water.
4)In my tap water the RA is positive and the pH would rise relative to a DI or RO water mash.
 
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