What Percentage of Bicarbonates Make it to Final Beer?

[rober695]

Hello,

To preface I have super hard temporary hardness in my water (305 PPM Bicarb). And have to this point not typically bothered with removing by any decarb means or dilluting with RO or Distilled in most of my batches EXCEPT lighter beers. I typically adjust alkalinity just through acid additions to my brewing liquour. The question is here. I recently brewed a Helles without the dillution step to remove minerals and honestly can't taste any level of mineraliness in the beer. It got me wondering....what PPM of Bicarb actually survive the brewing process to the final product? Typically you boil and cool to remove, so does it mostly precipitate out in the boil? What about the mash with all the enzymatic activity...does it precipitate out at all to the grain? Or does 100% of the bicarb actually make it to the beer? Thank you ahead of time guys.

 

[RPh_Guy]

can't taste any level of mineraliness

FYI, bicarbonate has no direct effect on flavor.

does 100% of the bicarb actually make it to the beer?

No, some reacts with acids and is evolved as CO2, and some reacts with calcium and precipitates, particularly during boiling.

Cheers

 

[An Ankoù]

You add acid to the brewing liquor. That'll reduce the HCO3 (bicarb) which will turn into the calcium salt of the acid you used and CO2. All is good, and everything is as it should be. After the acid and the malt and the boil there's no bicarb left.

edit.
Should have read what @RPh_Guy said. The same thing, really.

 

[Silver_Is_Money]

Study this chart. The final pH of beer is typically about 3.9 to 4.5. At about pH 4 the HCO3- (Bicarbonate) ionic species effectively ceases to exist. At about 4.5 pH perhaps only about 0.02% of it remains. And this room temperature chart does not take boiling into account.

 

[cire]

My brewing water is similar, typically 311 ppm bicarbonate. I also treat it with acid to reduce alkalinity to a suitable level and the beers have never had a mineraliness in over half a century of brewing. I've only ever read of such a defect since the advent of the internet.

 

[Silver_Is_Money]

If you ever do attempt to acidify whereby to reduce your Bicarbonate, here are some nominal acid additions for a specific volume of 5 gallons of your 305 ppm Bicarbonate ion water. The target here is a reduction to about 28 ppm of remaining Bicarbonate ion (or to about 23 ppm of remaining Alkalinity as CaCO3). The very same target as regards its nominal pH is ~5.40. Choose only one acid...

7.5 mL : 88% Lactic Acid
8.4 mL : 80% Lactic Acid
78.8 mL : 10% Phosphoric Acid
23.5 mL : 30% Phosphoric Acid
7.0 mL : 75% Phosphoric Acid
5.8 mL : 85% Phosphoric Acid
6.8 grams : Anyhdrous Citric Acid

 

[Silver_Is_Money]

Note: For the AMS (CRS) acid blend follow (duplicate) the suggestion as seen above for 30% Phosphoric Acid.

 

[RPh_Guy]

View attachment 772785
Study this chart. The final pH of beer is typically about 3.9 to 4.5. At about pH 4 the HCO3- (Bicarbonate) ionic species effectively ceases to exist. At about 4.5 pH perhaps only about 0.02% of it remains. And this room temperature chart does not take boiling into account.

The point being that bicarbonate becomes H2CO3 (carbonic acid) at beer pH, which is essentially the same as dissolved CO2 (carbon dioxide gas). And CO2 is of course present in a controlled amount in practically every beer regardless of the starting amount of bicarbonate in the liquor.

If you ever do attempt to acidify whereby to reduce your Bicarbonate, here are some nominal acid additions for a specific volume of 5 gallons of your 305 ppm Bicarbonate ion water. The target here is a reduction to about 28 ppm of remaining Bicarbonate ion (or to about 23 ppm of remaining Alkalinity as CaCO3). The very same target as regards its nominal pH is ~5.40. Choose only one acid...

7.5 mL : 88% Lactic Acid
8.4 mL : 80% Lactic Acid
78.8 mL : 10% Phosphoric Acid
23.5 mL : 30% Phosphoric Acid
7.0 mL : 75% Phosphoric Acid
5.8 mL : 85% Phosphoric Acid
6.8 grams : Anyhdrous Citric Acid

Can you help me understand the point of this? Why would a brewer want to arbitrarily reduce the bicarbonate?

As we know, the amount of acid required to achieve a proper mash pH depends on the malt characteristics and therefore cannot be determined based solely on the water minerals. Even the amount of "residual alkalinity" in the liquor depends on minerals beyond the bicarbonate.

 

[Silver_Is_Money]

Can you help me understand the point of this? Why would a brewer want to arbitrarily reduce the bicarbonate?

As we know, the amount of acid required to achieve a proper mash pH depends on the malt characteristics and therefore cannot be determined based solely on the water minerals. Even the amount of "residual alkalinity" in the liquor depends on minerals beyond the bicarbonate.

It is in line with the thinking behind AJ deLange's "The 0 Effective Alkalinity Method", which is a sticky within this Brew Science forum. I fully agree that when adjusting the mash to a desired pH target this step is redundant and thereby completely unnecessary. But then again, plenty of people do not attempt mash pH adjustment. And for the case of 305 ppm Bicarbonate and no mash pH adjustment it seems appropriate for many common beer styles.

 

[bkozak@precisionfermentat]

Scientific answers are at these links (probably more than you want to know) . . .

https://irp-cdn.multiscreensite.com/d34c7248/files/uploaded/Carbonate Chemistry.pdf
and

https://www.aqion.de/site/100
. . . from which you can get the table below. At normal beer pH's, over 94% of the dissolved CO2 exists carbonic acid and less than 6% as the bicarbonate ion.

%	%
H2CO3	HCO3-	pH
100	0	4.30
90	10	5.35
80	20	5.70
70	30	5.93
60	40	6.12
50	50	6.30
40	60	6.48
30	70	6.67
20	80	6.90
10	90	7.25
0	100	8.30

 

[cire]

Why would a brewer want to arbitrarily reduce the bicarbonate?

I doubt many brewers do this arbitrarily. It became standard procedure in Britain after the abolition of taxing malt to be replaced by taxation on the output from the mash tun, and water treatment was no longer considered tax avoidance. Few British trained brewers would ever consider mashing a pale beer with alkalinity >50ppm.