Hitting mash pH but excessive acid affecting taste

[Andre3000]

Recently, I'd been blaming tartness on 1272, but I'm beginning to realize I've been duped! I believe it's the bicarbonate (145 ppm) and hence, the amount of lactic acid I'm forced to add to reach a reasonable mash pH.

For example, a 4.5 gallon batch at 1.05 OG full volume BIAB: mash volume of 5.86 gal, I calculated 7 mL lactic 88% required to bring me to 5.35 pH. In reality, it always seems like the calculated value is undershooting the actual and in this example, I added another 1.5 mL to hit that 5.35 pH.

This is resulting in an easy 2 ml per gallon of final 88% lactic acid / gallon of beer, especially when I brew lighter beers. I've read conflicting info, but it seems like this is on the high end of the acceptable taste threshold for lactic acid additions.

Rather than sparge, I feel like the simplest thing here is to try to find some strong phosphoric acid and continue with full volume mashes since it will not impart a taste. But it can be hard to find. So alternatively, if I do a thicker mash and do not sparge, what's the ideal preboil top up water chemistry without adding more acid to hit my gravity as it pertains to the final product taste?

So many questions . Thanks in advance.

 

[ScrewyBrewer]

You could always dilute your water 50/50 with distilled or reverse osmosis water and halve your mineral content. Assuming a taste threshold for 88% lactic acid is 1.5 ml per gallon is a good rule of thumb.

 

[thehaze]

You can also switch to Phosphoric Acid. I know I did, and it was a much better decision. I use Phosphoric Acid at the 75% strength.

 

[Silver_Is_Money]

You can also switch to Phosphoric Acid. I know I did, and it was a much better decision. I use Phosphoric Acid at the 75% strength.

Is 75% an available concentration, or do you dilute 85% Phosphoric Acid to achieve 75%?

BTW, at around 72%-73% concentration, Phosphoric Acid can fairly reliably (as in 'for most all practical purposes') use off the shelf (or software derived) data for 88% Lactic Acid straight up on a mL for mL (1:1) basis.

 

[madscientist451]

Sorry this isn't the answer the OP is looking for, but....
If you are experiencing flavor problems and you suspect its the water, the easiest thing is to change the water instead of trying to manipulate it. If you need 6 gallons of water for 4.5 gallon batch and pay retail of $1/gallon for spring or distilled water at your local store, that raises your cost by about $ .13 per 12oz of beer. And as a previous post indicated, you can cut that in half if you only use 3 gallons of purchased water.
Is it worth putting in an R/O system for that?
I've also read that pre-boiling your brewing water may help.
Life's too short to make beer you don't really like.

 

[ajdelange]

You have several options many of which have been suggested. Your reported bicarbonate level of 145 suggests and alkalinity (and note that it is the alkalinity we are really interested in here) of about 2.4 mEq/L. That's not terrible but it is more than we would like for sure so getting rid of some of it (or all of it) would be nice. The rule of thumb says that you can dump all but about 1 mEq/L by simply heating the water to boiling for a few minutes. Just be sure that you calcium level is greater than 2.4 mEq/L (48 mg/L) by enough that after 1.4 mEq/L (28 mg/L) have been removed the remaining calcium is at the level you want.

A stiffer mash (less water) means less acid required to hit mash pH so you will get the benefit of proper mash pH but the story doesn't end there. If you then sparge with water that you haven't acidified kettle pH will be too high. So a possibility is to mash with your tap water (acidified) and then sparge with RO or DI water.

Or brew with RO water entirely. This will, of course, solve your problem with excess acid addition but also takes away any concerns about seasonal variations in your water supply.

Vintners' suppliers often offer 10% phosphoric acid. While it takes a larger addition to kill the same amount of alkalinity the nice thing about 10% (in addition to it not being so corrosive) is that its strength is about 1 N WRT mash pH.

 

[schematix]

Or brew with RO water entirely.

^^^ Best water advice there is.

 

[ajdelange]

Yes, when all is said and done, it really is.

 

[Andre3000]

You have several options many of which have been suggested. Your reported bicarbonate level of 145 suggests and alkalinity (and note that it is the alkalinity we are really interested in here) of about 2.4 mEq/L. That's not terrible but it is more than we would like for sure so getting rid of some of it (or all of it) would be nice. The rule of thumb says that you can dump all but about 1 mEq/L by simply heating the water to boiling for a few minutes. Just be sure that you calcium level is greater than 2.4 mEq/L (48 mg/L) by enough that after 1.4 mEq/L (28 mg/L) have been removed the remaining calcium is at the level you want.

A stiffer mash (less water) means less acid required to hit mash pH so you will get the benefit of proper mash pH but the story doesn't end there. If you then sparge with water that you haven't acidified kettle pH will be too high. So a possibility is to mash with your tap water (acidified) and then sparge with RO or DI water.

Or brew with RO water entirely. This will, of course, solve your problem with excess acid addition but also takes away any concerns about seasonal variations in your water supply.

Vintners' suppliers often offer 10% phosphoric acid. While it takes a larger addition to kill the same amount of alkalinity the nice thing about 10% (in addition to it not being so corrosive) is that its strength is about 1 N WRT mash pH.

I have access to the 10% phosphoric stuff locally. What do you mean 1 N with respect to mash pH?

What I'm understanding is if I simply top up without sparge, my preboil mash pH will be too low. What's the significance of this on the final product?

You guys may be right. I may have to bite the bullet on an RO system. Le sigh.

 

[schematix]

You can get a good enough RO system for about $100. A simple system with 2 pre-filters and the membrane is all you need for a tankless system. No need to make RODI water or have a tank unless with additional polishing filters unless you're going to put it under your kitchen sink as well.

 

[thehaze]

Is 75% an available concentration, or do you dilute 85% Phosphoric Acid to achieve 75%?

BTW, at around 72%-73% concentration, Phosphoric Acid can fairly reliably (as in 'for most all practical purposes') use off the shelf (or software derived) data for 88% Lactic Acid straight up on a mL for mL (1:1) basis.

It's stored bought and it's supposed to be 75% strength.

 

[RPh_Guy]

You could always dilute your water 50/50 with distilled or reverse osmosis water and halve your mineral content. Assuming a taste threshold for 88% lactic acid is 1.5 ml per gallon is a good rule of thumb.

~1.1mL of 88% lactic acid per 4L comes to 300ppm, by my calculation. Did you use a different taste threshold?

 

[ajdelange]

I have access to the 10% phosphoric stuff locally. What do you mean 1 N with respect to mash pH?

Lactic and phosphoric acids are 'weak' acids which means that the number of protons they can donate depends on mash pH. Each milliliter of 10% phosphoric acid will deliver 1.05 mEq of protons to a mash in bringing it to pH 5.4 so we say it is 1.05 N. 75% phosphoric is 12.2 N and 85% 14.8 N. 88% lactic is 11.45 N but your software doesn't know that and thinks its 11.77 N. So use that value when determining how much 10% (or other strength) phosphoric acid converts to x mL of lactic.

What I'm understanding is if I simply top up without sparge, my preboil mash pH will be too low. What's the significance of this on the final product?

What I was trying to say was that if you mash with treated tap water and then sparge with untreated tap water ketttle pH will be too high. So sparge with water that has been treated (resulting in perceptible acid in the flavor unless phosphoric is used) or is low in alkalinity (RO water). The consequence of high kettle pH is beer that is not as good as beer with proper kettle pH. I can't be, alas, more specific than that.

You guys may be right. I may have to bite the bullet on an RO system. Le sigh.

You may sigh at the prospect now but believe me when I say you will not be sighing after brewing with it a few times.

 

[Andre3000]

I did manage to find some 25% phosphoric acid for a reasonable price. I may go down that road first. Though I am definitely curious on the potential improvement brewing with RO could have on my beers.

Thanks for all the feedback everyone.

 

[ScrewyBrewer]

~1.1mL of 88% lactic acid per 4L comes to 300ppm, by my calculation. Did you use a different taste threshold?

My earlier reference to 1.5ml lactic acid per gallon is based on what little information I could fnd, from a reputable source.

I recently brewed a Kolsch using 12 gallons of RO water treated with 11 ml of 88% lactic acid, 2g calcium chloride and 3g epsom salt. The grains were 20lbs German Pilsner and 1lb Vienna malt. When tasting the treated water before adding in the grains it tasted tart. The mash pH sample taken 20 minutes into the mash and cooled to room temperature was 5.18. The finished beer didn't have a hint of tartness or any trace of lactic at all.

 

[Andre3000]

My earlier reference to 1.5ml lactic acid per gallon is based on what little information I could fnd, from a reputable source.

I recently brewed a Kolsch using 12 gallons of RO water treated with 11 ml of 88% lactic acid, 2g calcium chloride and 3g epsom salt. The grains were 20lbs German Pilsner and 1lb Vienna malt. When tasting the treated water before adding in the grains it tasted tart. The mash pH sample taken 20 minutes into the mash and cooled to room temperature was 5.18. The finished beer didn't have a hint of tartness or any trace of lactic at all.

What was your target OG? For a 12 gallon batch, these numbers seem quite ideal relative to what I find I'm having to add to adjust correctly.

 

[RPh_Guy]

After looking around a bit I suppose 400ppm (~1.5mL 88% per gal) is more widely accepted, though it greatly depends on the taster. I'm cursed with highly sensitive taste.
Some tasters in Kai's experiment were detecting as low as 200ppm.

It's the volume of finished beer that matters, not the amount of water treated because boiling concentrates the acid. So 1.5mL is safe per gallon of finished beer.

 

[ScrewyBrewer]

What was your target OG? For a 12 gallon batch, these numbers seem quite ideal relative to what I find I'm having to add to adjust correctly.

The OG was 1.052 and the FG was 1.009. I mashed 12 gallons of treated water in with the grains for a 13.25 pre-boil and an 11.75 gallon post boil volume.