Low Mash pH Effect on Taste in Pilsner

[micraftbeer]

I brewed a Pilsner Urquell clone yesterday. I was doing an experiment to quantify the effects of starter vs. non-starter by splitting my batch into 2 fermentors. Anyway, I've been starting to measure and try to adjust for mash pH. So BeerSmith2 was telling me to add 5 ounces of my 10% Phosphoric acid to bring the predicted pH down from 5.67 to my target of 5.2. My mash way undershot with the following values in my 90 minute mash:

- 18 min into mash: pH=4.41
- 30 min into mash: pH = 4.59
- 90 min into mash: pH = 4.86

I thought that was a lot of acid, but I haven't targeted a pH that low before since tracking my pH, and adjustment predictions from before were accurate so I just dumped it in (actually only had 4.9 oz).

When I pulled the lid off the kettle once the strike water had hit its target temperature, I caught a sweet odor and I thought to myself, "Why did I add so much dumb acid?". Tasting the wort samples, they all tasted fine. My wort sample after boil, when getting my OG measurement tasted good, but I did notice a slightly tart bite to it like an orange juice type of acidity.

My question is, would a low pH like this present itself as a particularly tart finished beer? Anyone have any experience with this?

Recipe for 7 gallon batch:
13.5 lbs German Pilsner
0.5 lbs Cara hell
0.15 lbs Dark Munich
2 oz. Saaz (6.5%) @ 90 minutes
1.35 oz. Saaz (6.5%) @ 15 min
1.35 oz. Saaz (6.5%) @ 5 min
Wyeast #2278 Czech Pilsner Lager
0.71 oz Saaz (6.5%) dry hop

Brew parameters:
- Mash for 90 min @ 151F
- Mashout for 10 min @ 168F
- Boil for 90 min

8.3 Gallons of this Base Water in the mash:
- Ca 24 ppm
- Mg 2.4 ppm
- Na 24.4 ppm
- SO4 0 ppm
- Cl 30.0 ppm
- HCO3 96.0 ppm

Mash water additions:
- 4.1 g Gypsum
- 7.1 g Epsom Salt
- 1.7 g CaCl

 

[Silver_Is_Money]

5 ounces of 10% Phosphoric Acid is 148 mL. That's a whopper load of acid.

The most positive thing you have going for you is that Bohemian yeasts typically finish high in final beer pH, and yeast is the final arbiter of beer pH.

 

[Silver_Is_Money]

Actually, given the source waters high alkalinity, if this was a no-sparge batch and presuming that there were ~10.5 gallons of mash water (and zero sparge water), I'm calculating 130 mL of 10% phosphoric to hit a mash pH of 5.2, with 148 mL hitting ~5.1 pH.

If however you did a large volume sparge, your overall mEq of acid countering mash water alkalinity would be far less, and your resultant mash pH would fall well below 5.1 or 5.2.

You might also hit a well lower mash pH than anticipated if either you or your LHBS mistakenly gave you a noticeably more acidic base malt than the German Pilsner base malt that you requested. Something like 2-Row Brewers.

 

[dpeters]

Not sure what the deal is with BeerSmith but I would suggest using Brun Water instead. I do not use BeerSmith for my water and PH, for some reason it does not work out. I hardly even take a PH reading anymore because Brun Water has always been really close.

 

[jcav]

Congrats on your attempt at the original Pilsner! Great beer when you can get it fresh and in a keg! I use BeerSmith also but I do not use their ph recommendations because for some reason they always seem to want you to add more than is required. I use the program for everything else though. For me I do what Gordon Strong recommends. I treat my strike water and add my salts and lactic acid to get it down to 5.5 with a ph meter. I do not mash with dark grains (roasted malts, chocolate malt) or crystal or caramel malts as they do not need to be mashed or converted. I add those grains when I start to ramp up to mash out and I only mash the base malts (pilsner, pale ale, two row, munich, vienna etc) that need to be converted. Nine times out of ten my mash ph is perfect after 15 minutes in with a ph meter to verify. This is what works for me, something to think about.

John

 

[micraftbeer]

Actually, given the source waters high alkalinity, if this was a no-sparge batch and presuming that there were ~10.5 gallons of mash water (and zero sparge water), I'm calculating 130 mL of 10% phosphoric to hit a mash pH of 5.2, with 148 mL hitting ~5.1 pH.

If however you did a large volume sparge, your overall mEq of acid countering mash water alkalinity would be far less, and your resultant mash pH would fall well below 5.1 or 5.2.

I edited my original post to clarify the volume of my mash water- 8.3 gallons.

Not sure what the deal is with BeerSmith but I would suggest using Brun Water instead. I do not use BeerSmith for my water and PH, for some reason it does not work out.

I might try Brun Water. My previous experience on an IPA and targeting a 5.4 pH, BS2 was spot on. But I'm not interested in brewing a batch and screwing it up by trying to hit a mash pH...

 

[Gnomebrewer]

As silver said, the tartness of the beer comes from the yeast, not so much from wort pH. The low mash pH is likely to impact efficiency (was it low?) and give a reduction in bitterness (low boil pH affects alpha acid utilisation). On a good note, you're at about the optimal pH for protein coagulation, so should have a nice, clear beer! I also find that Beersmith (BS2 and BS3) is useless as a water tool. I wanted to like it (it would be easier to have everything in the one file), but it just falls short of the mark.

 

[ajdelange]

The most positive thing you have going for you is that Bohemian yeasts typically finish high in final beer pH, and yeast is the final arbiter of beer pH.

Yeast can, where pH is low, secrete acid to lower it but I am not sure whether they can absorb protons in order to increase pH.

 

[ajdelange]

Managing the pH of a Pils isn't as big a deal as it is with some other styles. You have two alkalinities to fight: those of the water and that of the malt. Many of these beers are brewed with very low alkalinity water and so the malt becomes the major factor. Your alkalinity is about 1.6 mEq/L (you didn't tell me the pH and it doesn't make much difference anyway). That's not low so the simplest thing to do is either dilute with RO or simply add acid to the water until it's pH is your target mash pH. Now take some of that water and mash a pound of your grist to which you have added 2% (9 grams) of sauermalz. Check the pH. If it is too low try again with more sauermalz. If it is high try again with less. You should find an addition of from 1 - 4% which gets you pretty close to a good mash pH. This is much better than relying on a calculator.

 

[SoCal-Doug]

One of my favorite beers! You should be fine with what happened but call it a lesson learned. NEVER use beersmith for pH adjustments. Especially with pilsner malts. It's total crap (version 2 and 3). Period, end of story.

 

[cooper]

@micraftbeer, how did it turn out? Did you get a final pH reading of it after fermentation? Interesting stuff!

 

[micraftbeer]

It's difficult for me to quantify a precise effect from this, but the beer is delicious. I don't really like the commercial version, I just went with this recipe to try to flush out a difference in fermentation process. So I smell the hop aroma, and think how u don't really care for Saaz hops, taste the yeaye flavor and think how u don't really like the teyea flavor. Then it's over and I'm overwhelmed at how delicious and drinkable it is, and I have to have another.

I'll try to grab a pH reading if the final beer and post.

 

[Vale71]

Just out of curiosity, did you test for conversion at mash-out?

 

[ESBrewer]

Just out of curiosity, did you measure OG & FG and how was it? I would say that a very low pH mainly affects fermentability because the optimal activity range of mash enzymes is between pH 5 - pH 6. OG is probably fine. But the FG may be a little bit higher than it would have been if mashed above pH5. Also, low pH may have adverse effect on hop utilization (less IBUs from the same amount of hops, which may feel pleasant or not based on recipe and personal preference). Low pH is good for lautering, clarity, head retention, microbial stability/shelf life. The final product probably won't feel overly tart unless the final beer pH went all the way down to extremities.

 

[Vale71]

I would go so far to say that such a low PH would have made complete conversion of starch impossible. Alpha-amylase will hardly show any activity at such a low PH value and complete conversion without alpha-amylase activity is impossible.

 

[micraftbeer]

Looks like I did not check for conversion with Iodine test, probably because the recipe asked for a 90 minute rest at 151F. Here's some numbers:

Measured OG: 1.057
BS Calculated Brewhouse Efficiency: 75.8% (which is better than my typical ~72%)
Measured FG: 1.011
Fermentation/Yeast attenuation: 80% (Wyeast website says this yeast will get you 70-74%)
Finished beer pH (measured 11 days after kegging): 4.36 @ 20.4C

Mash density: 1.5 qt/lb in Wort Hog eBIAB system with constant slow recirculation through mash & mashout steps. Batch sparging through grain bag suspended over kettle until getting close to target pre-boil gravity. Lots of mash bag squeezing to get all of the juices out of the mash grain.

 

[Silver_Is_Money]

I would go so far to say that such a low PH would have made complete conversion of starch impossible. Alpha-amylase will hardly show any activity at such a low PH value and complete conversion without alpha-amylase activity is impossible.

Brulosophy intentionally drove mash pH down to 4.43 by hitting the mash water with 19 mL of 88% lactic acid, and the resulting beer came out just fine. It attenuated identically to a beer made identical to it sans mashed at 5.33 pH, and in a triangle test the blind taste testers could not distinguish between them. They finished at nearly identical pH's.

This should also indicate that despite what almost everyone parroting old myths will tell you in regard to being able to taste lactic acid, the taste testers couldn't taste that either, else they would have successfully identified the odd beer out. The taste testers were not informed of the differences in the beers sitting before them until after they had all voted. They were merely asked to identify the single odd beer out when given 2 of the 5.33 mash pH beer samples and 1 of the 4.43 mash pH beer samples. And they could not identify it. There is no Lactobacillus present within 88% lactic acid. Lactobacillus is what gives soured beer its sour taste.

19 mL of 88% lactic acid is somewhere around the acid equivalent of 217 mL of 10% Phosphoric acid.

 

[Vale71]

Looks like I did not check for conversion with Iodine test, probably because the recipe asked for a 90 minute rest at 151F. Here's some numbers:

Measured OG: 1.057
BS Calculated Brewhouse Efficiency: 75.8% (which is better than my typical ~72%)
Measured FG: 1.011
Fermentation/Yeast attenuation: 80% (Wyeast website says this yeast will get you 70-74%)
Finished beer pH (measured 11 days after kegging): 4.36 @ 20.4C

Mash density: 1.5 qt/lb in Wort Hog eBIAB system with constant slow recirculation through mash & mashout steps. Batch sparging through grain bag suspended over kettle until getting close to target pre-boil gravity. Lots of mash bag squeezing to get all of the juices out of the mash grain.

For the record, you can check for conversion in finished beer too. This is actually done routinely in large breweries, albeit in a lab with expensive equipment. You can just take a sample of the beer, degas it thoroughly and then do the iodine test as you would with wort.

 

[Vale71]

Brulosophy intentionally drove mash pH down to 4.43 by hitting the mash water with an extra 17 mL of 88% lactic acid, and the resulting beer came out just fine. It attenuated identically to a beer made identical to it sans mashed at 5.3 pH, and in a triangle test the blind taste testers could not distinguish between them. They finished at nearly identical pH's.

This should also indicate that despite what almost everyone parroting old myths will tell you in regard to being able to taste lactic acid, the taste testers couldn't taste that either, else they would have successfully identified the odd beer out. The taste testers were not informed of the differences in the beers sitting before them until after they had all voted.

FG is no proof of complete conversion. If you have 40 g/l of dextrines or 20 g/l of dextrins plus 20 g/l of starch the hydrometer reading will be the same. A fact that is probably unknown to the Brulosophy guys as I didn't see a iodine test mentioned anywhere in their report.
As for their tasting panels, they never seem to be able to detect any difference no matter what, so much that one has to wonder if they're purposefully only picking 80 years old chainsmokers for the tests...

 

[Silver_Is_Money]

I found the Brulosophy link:

http://brulosophy.com/2017/01/30/wa...he-impact-of-low-mash-ph-exbeeriment-results/

 

[Vale71]

Took a look at it again. Nowhere do they mention testing for conversion. They also used a no-sparge method which might have helped by leaving starch trapped in the grains instead of washing it out. IMHO the methodology they employ is one step away from rubbish.

 

[cooper]

Looks like I did not check for conversion with Iodine test, probably because the recipe asked for a 90 minute rest at 151F. Here's some numbers:

Measured OG: 1.057
BS Calculated Brewhouse Efficiency: 75.8% (which is better than my typical ~72%)
Measured FG: 1.011
Fermentation/Yeast attenuation: 80% (Wyeast website says this yeast will get you 70-74%)
Finished beer pH (measured 11 days after kegging): 4.36 @ 20.4C

Mash density: 1.5 qt/lb in Wort Hog eBIAB system with constant slow recirculation through mash & mashout steps. Batch sparging through grain bag suspended over kettle until getting close to target pre-boil gravity. Lots of mash bag squeezing to get all of the juices out of the mash grain.

Looks like it came out great! You said it tasted delicious too so I'd call it a win. It would be a good test as Vale71 mentioned to see if everything did get fully converted, but I'd be super happy with those numbers and that final beer pH is right where I'd like it to be if I were testing it.

 

[Silver_Is_Money]

Do yeast convert starch into alcohol?

 

[cooper]

Do yeast convert starch into alcohol?

ExBEERiment idea!

 

[Vale71]

Do yeast convert starch into alcohol?

Not Saccharomyces.

 

[Silver_Is_Money]

Not Saccharomyces.

Then what caused the Brulosophy pH 4.43 mashed wort to ferment from ballpark 1.050 OG to ballpark 1.017 FG?

 

[Vale71]

The amount of fermentable sugars? I don't really understand what this has got to do with incomplete conversion?

 

[Silver_Is_Money]

The amount of fermentable sugars? I don't really understand what this has got to do with incomplete conversion?

Would it not be the case that if starch is present where sugar ought to be (as you contend), the beer would not ferment out to a normal FG?

 

[Vale71]

No, not necessarily. Final gravity only tells you the amount of non-fermentable solute in the finished beer, irregardless of whether a fraction of it is made up of starch or not. I thought I'd explained that in a previous post?
To be certain of complete conversion an iodine test should always be performed, that's the only way of clearly distinguishing between dextrins and starch.

 

[hopjuice_71]

There is some information in this thread that doesn't compute for me. It seems logic and evidence is more in favour of Silver_Is_Money.. ..but it might just be that the flow of the thread reads strangely. If starch conversion is complete then the mix of fermentables and non-fermentables (dextrins) give an expected OG and eventually a "normal" FG is reached. If conversion is incomplete then the resulting high amount of dextrins and soluble starches, i.e. non-fermentables, would lead to an anomalously high FG. It seems in most cases where people have accidentally or intentionally hit a low mash pH they hit reasonable FGs, supporting the idea that conversions are relatively efficient. This anecdotal evidence is further supported by the brewing and non-brewing research literature that shows the many sugar-converting enzymes from barley function well at pHs far outside what is typically considered the "norms" for mashing pH. Seems the real questions are what effect does pH have on the other types of enzymes in mash, how mash pH tracks through kettle pH and final beer pH, and how these things influence final perception of the beer. In this case, I'm glad the OP ended up with nice beer.