Final Beer pH -- Phosphoric Acid Off-flavor

[Viridian]

I have been focusing on making NEIPAs for a year and a half now. I've recently been adjusting my final beer pH with acid, in order to achieve a final beer pH of about 4.2 -- 4.4. The beers are usually 4.8 -- 4.9 post ferm, which is mostly due to heavy dry hopping (3.5lb/BBL charge), which increases pH. As I am still a start-up, I operate out of 5gal corny kegs still. My process so far has been to crash the carboys, close-loop transfer into a purged keg, seal the keg, and take a pH reading. After this, my process is to unscrew the gas-IN port, put in whatever acid I determine it will need, seal it back up, take another pH reading, and rinse and repeat if it's still not within desired band. Recently, I have been using Phosphoric Acid 10%, at about 140mL quantity (which results in about 0.9% into finished beer, or 9,000 PPM). After carbonation and letting the beer condition for a few days, when the beer is "ready", I've noticed that the flavor and aroma are stunted and different. I can clearly taste the phosphoric acid, and on top of that, it seems to severely damage the flavor and aroma that was once there, leaving behind an NEIPA that is pretty weak.

I have been trying to get all beers within 4.2 -- 4.4 because of heavy research indicating that this pH band results in the most crisp / refreshing / flavorful drinking experience. Based on my experience, I agree - beer within this pH range tastes the best.

My question - isn't Phosphoric Acid supposed to be flavor/odor-less? If it is - with that being said - might it still have enough of an aroma that it conflicts with the volatile aroma oils from the hops? Am I using too much phosphoric, and need to switch to a different acid? Perhaps should I just aim to reduce the pH of my casting wort to 4.5 instead of 5.0 - which assumes that the fermentation process will take care of any flavor/aroma from the acid?

I am anxious for your help on this. Thanks and cheers.

[Fishweir]

I don't have a lot of experience with NEIPA so take my information with a grain of salt. I guess my first question is what is your pre boil, post boil, and post ferment/pre dry hop pH? That info will provide some direction to head as far as a target pH.

Also, I would imagine that your final still beer pH should be 4.4 (towards the high end of your range). According to a lot of literature that is the sweet spot for clarity/taste/perceived bitterness etc. (clarity doesn't matter to you).

[Viridian]

I don't have a lot of experience with NEIPA so take my information with a grain of salt. I guess my first question is what is your pre boil, post boil, and post ferment/pre dry hop pH? That info will provide some direction to head as far as a target pH.

Also, I would imagine that your final still beer pH should be 4.4 (towards the high end of your range). According to a lot of literature that is the sweet spot for clarity/taste/perceived bitterness etc. (clarity doesn't matter to you).

Mash pH = 5.5
Sparge pH = 4.8

Pre-Boil pH = 5.3
Post-Boil pH = 5.1

Post-hop-stand pH = 5.3

(Into Fermenter)

Pre-Dry Hop pH = 4.5 or so

Finished pH = 4.8 -- 4.9

What I am wondering is if adding acid post ferment is the problem. I admit 9000 PPM is a bit high (albeit its only 10% concentrate). I am searching endlessly, and I can't find anything on what the odor/flavor threshold is for phosphoric acid, and furthermore how much of the phosphate the yeast would likely consume (thus reducing odor/flavor if added before ferm).

Thanks!

[Viridian]

And I will open this up to one more question - what kind of acid do you guys use for reducing final beer pH? Or what kind of acid in general, for mash/sparge/kettle - to achieve proper casting wort pH? How much usually?

[Fishweir]

So first thing that jumps out to me is maybe try to shoot for a pre boil of 5.2 or 5.1. Get your post boil down to 4.9. That would hopefully lower your hopstand pH. That .1 difference can have you putting 30mL less of phosphoric acid in at the end. Might lower you past the threshold.

As far as taste is concerned you have me a bit stumped. But I didn't want to tell you that 99.9% of the time, phosphoric acid will not break all the way down to phosphate in beer. The pka3 of phosphoric acid is something like 2x10-13. So complete break down of phosphoric acid into phosphate most likely exists in such small amounts, that the yeast wont remove that much. That being said, beer is very dynamic and yeast are amazing, so I have no hard research evidence to support my statement.

I don't do a lot of adjustment post ferment with my beers. If I do, I use phosphoric, but never as much (percentage) as you are saying. If we miss a finish beer pH (which we avoid at all costs by adjusting along the way) its often by .05-.1 pH.

sorry I cant be of more help!

[Viridian]

So first thing that jumps out to me is maybe try to shoot for a pre boil of 5.2 or 5.1. Get your post boil down to 4.9. That would hopefully lower your hopstand pH. That .1 difference can have you putting 30mL less of phosphoric acid in at the end. Might lower you past the threshold.

As far as taste is concerned you have me a bit stumped. But I didn't want to tell you that 99.9% of the time, phosphoric acid will not break all the way down to phosphate in beer. The pka3 of phosphoric acid is something like 2x10-13. So complete break down of phosphoric acid into phosphate most likely exists in such small amounts, that the yeast wont remove that much. That being said, beer is very dynamic and yeast are amazing, so I have no hard research evidence to support my statement.

I don't do a lot of adjustment post ferment with my beers. If I do, I use phosphoric, but never as much (percentage) as you are saying. If we miss a finish beer pH (which we avoid at all costs by adjusting along the way) its often by .05-.1 pH.

sorry I cant be of more help!

Thanks for the replies man. Well - even if I reduce the pH of my pre-boil / post-boil / casting wort --> I would still have to do so using lactic or phosphoric, thereby adding to the taste. Do I keep it under the threshold by using a combination?

Also - my thinking was that on the first 2 days of fermentation (before I drop hop anyways), the yeast will drive off aroma from phosphoric and/or lactic by means of C02 generation.

Is there a better acid to use? Hydrochloric? Citric?

[Matt Simpson]

I have been focusing on making NEIPAs for a year and a half now. I've recently been adjusting my final beer pH with acid, in order to achieve a final beer pH of about 4.2 -- 4.4. The beers are usually 4.8 -- 4.9 post ferm, which is mostly due to heavy dry hopping (3.5lb/BBL charge), which increases pH. As I am still a start-up, I operate out of 5gal corny kegs still. My process so far has been to crash the carboys, close-loop transfer into a purged keg, seal the keg, and take a pH reading. After this, my process is to unscrew the gas-IN port, put in whatever acid I determine it will need, seal it back up, take another pH reading, and rinse and repeat if it's still not within desired band. Recently, I have been using Phosphoric Acid 10%, at about 140mL quantity (which results in about 0.9% into finished beer, or 9,000 PPM). After carbonation and letting the beer condition for a few days, when the beer is "ready", I've noticed that the flavor and aroma are stunted and different. I can clearly taste the phosphoric acid, and on top of that, it seems to severely damage the flavor and aroma that was once there, leaving behind an NEIPA that is pretty weak.

I have been trying to get all beers within 4.2 -- 4.4 because of heavy research indicating that this pH band results in the most crisp / refreshing / flavorful drinking experience. Based on my experience, I agree - beer within this pH range tastes the best.

My question - isn't Phosphoric Acid supposed to be flavor/odor-less? If it is - with that being said - might it still have enough of an aroma that it conflicts with the volatile aroma oils from the hops? Am I using too much phosphoric, and need to switch to a different acid? Perhaps should I just aim to reduce the pH of my casting wort to 4.5 instead of 5.0 - which assumes that the fermentation process will take care of any flavor/aroma from the acid?

I am anxious for your help on this. Thanks and cheers.

I have used acid in the HLT to do this. I always felt that phos left a sharp taste to the beer. I started using lactic acid instead and was really happy with the results.

Matt Simpson
Tennessee Brew Works

[jebzter]

pH adjustment post ferment, and post dry hop is not a common practice at all. You will see better hop utilization at the slightly higher pH as well. What research have you come across that says the 4.2-4.4 pH is the best target? I think that applying blanket parameter across all styles wont yield any better beers, except for the ones that should have that pH. Ive been a member of the MBAA for a while, and I haven't seen a TQ article on this yet.

[Gambrinus64]

Aloha,

I have a couple options for you:

- Have you thought about doing an acid rest? In the 95-110 range... this can aid in reducing your mash pH to help lower everything throughout the process.

- I am also a proponent of lactic acid over phosphoric, it has a much cleaner flavor, you can use an 88% solution and most likely use less.

- Have you calibrated your pH meter recently? Lower end models aren't very reliable and need constant re-calibration. The probe storage solution should be changed out every week and you should replace the bulk pH storage solution 3 months after it has been opened, more consistent pH results may aid in less acid use.

Best of luck!

- Kevin W.

[Viridian]

pH adjustment post ferment, and post dry hop is not a common practice at all. You will see better hop utilization at the slightly higher pH as well. What research have you come across that says the 4.2-4.4 pH is the best target? I think that applying blanket parameter across all styles wont yield any better beers, except for the ones that should have that pH. Ive been a member of the MBAA for a while, and I haven't seen a TQ article on this yet.

Hop utilization being alpha acid isomerization that you're referring to -- right? That's entirely different when compared to extraction of aroma oils from the hop charge.

There are countless white papers around the internet (wiley library is a good start) that reference common pH ranges of certain beer styles, and their benefits. Aside from helping with colloidal stability and microbial mitigation, the pH affects the flavor perception of the beer.

[Viridian]

Aloha,

I have a couple options for you:

- Have you thought about doing an acid rest? In the 95-110 range... this can aid in reducing your mash pH to help lower everything throughout the process.

- I am also a proponent of lactic acid over phosphoric, it has a much cleaner flavor, you can use an 88% solution and most likely use less.

- Have you calibrated your pH meter recently? Lower end models aren't very reliable and need constant re-calibration. The probe storage solution should be changed out every week and you should replace the bulk pH storage solution 3 months after it has been opened, more consistent pH results may aid in less acid use.

Best of luck!

- Kevin W.

The acid rest is a good idea - I appreciate that - something that I hadn't thought about. That would certainly reduce the total amount of acid needed for the entire batch. With you being a proponent for lactic acid - how much have you been able to get away with using without a negative affect on flavor? I think the trouble is that NEIPAs are so delicate due to 90% of flavor being driven from aroma oils.

Regarding the pH meter - I'm covered there. I have an Anaheim Scientific 771 - I calibrate it every two weeks, replace the storage solution often and probably need to replace the bulk solution more often. That being said - I'm fairly confident that my pH readings are on.

[Gambrinus64]

The acid rest is a good idea - I appreciate that - something that I hadn't thought about. That would certainly reduce the total amount of acid needed for the entire batch. With you being a proponent for lactic acid - how much have you been able to get away with using without a negative affect on flavor? I think the trouble is that NEIPAs are so delicate due to 90% of flavor being driven from aroma oils.

Regarding the pH meter - I'm covered there. I have an Anaheim Scientific 771 - I calibrate it every two weeks, replace the storage solution often and probably need to replace the bulk solution more often. That being said - I'm fairly confident that my pH readings are on.

I understand that cost is a prohibitive factor in regards to your brewery size... but odds are that pH meter isn't as accurate as you would think. Something like this https://www.thermofisher.com/order/c...170816174029:s is much more accurate but still requires constant calibration, we calibrate ours daily. I know someone else said it before but I also do not like the idea of adjusting pH post fermentation; however, I have used lactic to add an acidic kick to some firkins I have made and the flavor is always very clean. You will have a more consistent and quality product if adjustments are made to process/ingredients to obtain the pH you want rather than just adjusting it artificially at the end.

Have you thought about possibly reducing your hop charge post ferm 3.5lbs/bbls is HUGE and I would imagine you have ventured into the area of diminishing returns. This could be a big cost savings to you as well.

Good luck!

-Kevin W.

[Viridian]

I understand that cost is a prohibitive factor in regards to your brewery size... but odds are that pH meter isn't as accurate as you would think. Something like this https://www.thermofisher.com/order/c...170816174029:s is much more accurate but still requires constant calibration, we calibrate ours daily. I know someone else said it before but I also do not like the idea of adjusting pH post fermentation; however, I have used lactic to add an acidic kick to some firkins I have made and the flavor is always very clean. You will have a more consistent and quality product if adjustments are made to process/ingredients to obtain the pH you want rather than just adjusting it artificially at the end.

Have you thought about possibly reducing your hop charge post ferm 3.5lbs/bbls is HUGE and I would imagine you have ventured into the area of diminishing returns. This could be a big cost savings to you as well.

Good luck!

-Kevin W.

Unfortunately a "real" pH meter like that is not something that will be purchased until I am fully capitalized early next year. I agree that my likely path forward is to aim to have my casting wort have a pH of 4.5 or so - which should result in ferment bringing it down to 4.0, and then dry hops raising it to ~4.3. We will see. The problem is, short of performing an acid rest, I would need to use a substantial amount of lactic acid 88% to achieve a casting wort of 4.5 or so. This begs the question - how much lactic is too much? I would anticipate needing 21mL of lactic acid 88% in 4.5gallon batch to achieve this, resulting in about 1230PPM of lactic acid 88% in the batch.

Regarding the hops - yes 3.5lbs/BBL is huge, in fact its a shit load of hops. However, with NEIPAs, extracting aroma oils in massive amounts is what gives you a beer that tastes and smells like a basket of fruit

[Fishweir]

I with Kevin on this. I think you are beyond the point where you would perceive a difference. If you did a double blind taste test with 2lb/BBL and 3.5lb/BBL, I bet you wouldn't notice. That's a huge dry hop. Again, I don't make and have never made a NEIPA, but from what I know and have tasted in the style, the difference isn't in hopping technique but in water (high sulfate), use of flour/lactose (in some cases), and the use of oats/wheat with high mast temp.

I feel like if you lower your DH lb/bbl you it would help your pH problem out. Brew a 5 gallon batch that way, and see what happens!

[Viridian]

I with Kevin on this. I think you are beyond the point where you would perceive a difference. If you did a double blind taste test with 2lb/BBL and 3.5lb/BBL, I bet you wouldn't notice. That's a huge dry hop. Again, I don't make and have never made a NEIPA, but from what I know and have tasted in the style, the difference isn't in hopping technique but in water (high sulfate), use of flour/lactose (in some cases), and the use of oats/wheat with high mast temp.

I feel like if you lower your DH lb/bbl you it would help your pH problem out. Brew a 5 gallon batch that way, and see what happens!

It would only marginally help the pH (by about 0.1 or so) - I used to use only 2lb/BBL. High chloride, not sulfate - sulfate would bring out bitterness perception which is not desired for style.

Thanks for suggestions!