Less dilution, more acid - or - more dilution, more salts?

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bae388

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Hi guys,

I'm working on learning as much about mash water chemistry as I can before I dive into creating a water profile for my next batch. I seem to be getting differing opinions on acids vs. salts.

In my case, for the IPA I'm going to be brewing, I have less minerals in my base water than what I need. I would have to add 5.8g gypsum to my mash and 7.4g to my sparge, as well as .7g epsom to my mash and .9g to my sparge to raise the minerals to the desired levels (based on Bru'n Water's Pale Ale profile). However, without diluting, I will need to add 1.8mL of lactic acid to my mash, and 4.2mL to my sparge water.

If I decided to dilute my water with say 25% distilled water, I would have to add 6.3g gypsum to my mash and 8.1g to my sparge, 1.2g epsom to my mash and 1.6g to my sparge, and .5g calcium chloride to my mash and .7g to my sparge to raise the minerals to the desired levels. With diluting, I will only need to add .7mL of lactic acid to my mash, and 3.2mL to my sparge water.

So, if I don't dilute, I end up with 14.8g of salts and 6mL of lactic acid total. With the diluted water, I end up with 18.4g of salts and 3.9mL of lactic acid.

Anyways.... what's better? More acids or more salts? To dilute or not to dilute?

Any help would be appreciated!
 

WoodlandBrew

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Can you provide your water profile? Assuming your water is pretty good to start, and it sounds like it is, I would probably not dilute. Although I would probably skip the MgSO4. Malt has enough magnisium is it. More calcium is better for most water I have seen (again, it depends on what you have)

Also the sparge acid additions seem quite high. The spread sheets don't seem to work well for my grist, and it might be the same for you. It seems to be more reliable to dough in, and then measure pH.
 

mabrungard

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Brewing a hoppy beer is now about the only time I recommend adding magnesium to brewing water. I feel its beneficial to the flavors you want in a hoppy ale. You don't need to add it to other beers. But if added at very low levels, it doesn't detract.

Regarding which to go...more acid or more minerals...it depends. If using lactic, then you are limited in how much acid you can use without taste effects. Bru'n Water allows you to see what the amount of bicarbonate you are neutralizing by looking at the negative bicarbonate reading on the acid addition line of the Water Adjustment sheet. The taste threshold for lactate in beer is about 400 ppm, but some yeasts excrete more lactate than others. I like to keep the lactate to 200 ppm or less. That is equal to the -bicarb value. So, if your water has a lot of alkalinity, you may need to dilute and add the minerals back instead of just neutralizing the excess bicarb. Moving to phosphoric acid avoids that limit since its relatively flavor-free in beer.
 

Kaiser

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If you have to add minerals and lactic acid I suspect that your water is high in bicarbonate. But if its high in bicarbonate what are the metal ions that are elevated?

Check out this water calculator: http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator for your brewing water calculation needs. It also shows the lactic acid additions as an equivalent % acid malt in the grist.

Kai
 
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bae388

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Thank you to all of you for your helpful replies!

Brewing a hoppy beer is now about the only time I recommend adding magnesium to brewing water. I feel its beneficial to the flavors you want in a hoppy ale. You don't need to add it to other beers. But if added at very low levels, it doesn't detract.

Regarding which to go...more acid or more minerals...it depends. If using lactic, then you are limited in how much acid you can use without taste effects. Bru'n Water allows you to see what the amount of bicarbonate you are neutralizing by looking at the negative bicarbonate reading on the acid addition line of the Water Adjustment sheet. The taste threshold for lactate in beer is about 400 ppm, but some yeasts excrete more lactate than others. I like to keep the lactate to 200 ppm or less. That is equal to the -bicarb value. So, if your water has a lot of alkalinity, you may need to dilute and add the minerals back instead of just neutralizing the excess bicarb. Moving to phosphoric acid avoids that limit since its relatively flavor-free in beer.
Does the –bicarb level include the –bicarb level added to the sparge water? If not, and I use the –bicarb listed on the mash adjustment sheet to calculate the total:

Not Diluted:
Mash –bicarb = -76.4 (1.8mL) lactic acid
Sparge –bicarb = 4.2mL (calculated from sparge sheet) / 1.8mL * -76.4 = -178.3
Total –bicarb = -76.4 + -178.3 = -254.7

This –bicarb of -254.7 would be over your recommended 200pm level.

Diluted (25%):
Mash –bicarb = -28.6 (.7mL) lactic acid
Sparge –bicarb = 3.2mL (calculated from sparge sheet) / .7mL * -28.6 = -130.7
Total –bicarb = -28.6 + -130.7 = -159.3

Would this be right? If so, I’ll go with the diluted water for this next batch. Thank you for sharing your recommended max lactate level. I don’t want my beer to taste too minerally (trying to reach the high sulfate level in your Pale Ale profile), but I certainly don’t want to taste the lactic acid.

Also, since I have this opportunity to speak with someone so knowledgeable… when the sparge acid additions are calculated on the spare acidification sheet, which is then transferred over to the adjustment summary sheet, I notice that the salt additions are not figured in to lower the sparge pH… just the acid is. I’m concerned that if I add the recommended acid to my sparge water, which according to the sheet will drop my pH down to 5.85, the additions of the salts will drop the pH even lower. Should I be concerned? I’m purposely staying on the high end of the recommended range of 5.5 – 6.0 to account for the unknown. I don’t have a pH tester so I’m banking on the spreadsheet being accurate.

Thank you again for taking the time to help me! Your spreadsheet is truly amazing!


Can you provide your water profile? Assuming your water is pretty good to start, and it sounds like it is, I would probably not dilute. Although I would probably skip the MgSO4. Malt has enough magnisium is it. More calcium is better for most water I have seen (again, it depends on what you have)

Also the sparge acid additions seem quite high. The spread sheets don't seem to work well for my grist, and it might be the same for you. It seems to be more reliable to dough in, and then measure pH.
Thanks for the advice about the MgSO4 addition. My base water already has 14ppm Mg and the profile calls for 18ppm Mg, so there really is no reason to add. But if I dilute, I will probably just add a little to get closer to the profile.

I guess I have to go out and invest in a pH meter one of these days. I’m currently just trying to shoot for the middle in the acceptable pH ranges of mash and sparge to leave room for error incase Bru’N Water happens to be off a little (due to my own error I'm sure). Obviously, I won't be able to know if I'm off without a pH meter… I am certainly crossing my fingers that it’s pretty accurate.


If you have to add minerals and lactic acid I suspect that your water is high in bicarbonate. But if its high in bicarbonate what are the metal ions that are elevated?

Check out this water calculator: http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator for your brewing water calculation needs. It also shows the lactic acid additions as an equivalent % acid malt in the grist.

Kai
Yes, my base bicarbonate is high.

Calcium (Ca) 59.0
Magnesium (Mg) 14.0
Sodium (Na) 19.0
Potassium (K) 2.0
Iron (Fe) 0.0
Nitrate (NO3) 14.6
Nitrite (NO2) 0.0
Fluoride (F) 0.0
Sulfate (SO4) 36.0
Chloride (Cl) 44.0
Carbonate (CO3) 0.2
Bicarbonate (HCO3) 185.0
Alkalinity 152
pH 7.4
 

WoodlandBrew

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How many ml of %88 lactic is 200ppm in 10 gallons?
200ppm is 200E-6 is 0.02%
88%/0.02% is 0.0227%
10 gallons x 0.0227% is 0.00227 gallons
0.00227 gallons * 3785.41178 is 8.60 ml

So that's the recommended flavor safe threshold?
 
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bae388

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200ppm is 200E-6 is 0.02%
88%/0.02% is 0.0227%
10 gallons x 0.0227% is 0.00227 gallons
0.00227 gallons * 3785.41178 is 8.60 ml

So that's the recommended flavor safe threshold?
If that is the calculation, it's definately good to know... I'll have to add that to a separate sheet on Bru'n to see where my lactic acid limit should be. Do you know if that amount would be the maximum total amount added to the total water (not including boil off, trub, etc...)? Or, would it be the recommended amount for the post boil volume? So, if 10gal is my total water, and 5.9gal is my post boil, which one would I use in the formula?

Thanks!
 

mabrungard

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The 200 ppm value is a SWAG based on the reported taste threshold of 400 ppm for lactate in beer as reported in Malting and Brewing Science. There are several factors that influence my recommendation to provide a factor of safety between that reported taste threshold and the added lactic acid quantity. The first is that different people have differing sensitivity to lactate taste. I assume that 400 ppm is the average taster. There are super-tasters that would have a much lower tolerance. The second reason is that differing yeasts produce lactate or lactic acid in their fermentation. So there would be some lactate in beer without the brewer adding lactic acid.

With regard to the OP's alkalinity, it is similar to the level I had to deal with when I was brewing in Tallahassee. I didn't note a lactic flavor, but maybe I'm not sensitive to it. The best work-around may be to use phosphoric acid or possibly perform a comparison of those acids in successive brews.
 
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bae388

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Martin,

My lactate should be well under 200ppm, so I think I am safe. However, in regards to the calculation of -bicarb in Bru'n, is that for the mash or both the mash and the sparge? I believe I know how to calculate the total -bicarb/lactate (as shown in my earlier post), do you think that is the correct way of doing it? Also, the sparge acidification sheet doesn't figure in the pH drop due to the salt additions in the sparge, only the acid. Should I be concerned? How much should I figure on for the pH drop? I am thinking anywhere from .05-.23 depending on the salt additions.
 

mabrungard

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Oh, I missed the questions in post #6 above.

No, the calculations above are not correct. The bicarbonate neutralization (-bicarb) is in mg/l units. So the volume of water treated enters the calculation. For example, the 76.4 mg/l of neutralization in the first mash example required 1.8 mL to treat X gallons or 1.8/X mL/gallon. I don't know what the mash water volume was, so I inserted X.

The calculation to figure the amount of bicarbonate neutralization in the sparging water is not appropriate in this case. The way it was done above should produce the same 76.4 mg/L neutralization if the volumes of water for the mash and sparge were included in the calculations. But since sparging water is not neutralized to the same degree as mashing water, it is not appropriate to use the calculation above.

A more appropriate way to evaluate the concentration of bicarbonate neutralized is to look at the difference in the starting and ending alkalinity. Say you are at 152 ppm alkalinity as CaCO3 and you want to end up at 25 ppm. That is a reduction of 127 ppm alkalinity. 1 ppm alkalinity (as CaCO3) is equal to 1.22 ppm of bicarbonate neutralized. So the bicarbonate neutralized by the sparge acidification is 127ppm x 1.22 = 155 ppm bicarb (-155 ppm bicarb). Since lactic acid is monoprotic, that means that 155 ppm of lactate is added to the sparging water when neutralizing that much alkalinity.

To figure out the average lactate ion addition to the kettle wort, you would have to do a volume-weighted averaging of the lactate ion additions from the mash and sparge.

You are correct that the mineral additions to sparging water are not considered to further reduce the pH of the sparging water. I suppose that the phytin in the wort could still react with the Ca and Mg to produce more acid, but the concentration of phytin is significantly reduced as the sparging progresses. Therefore, its appropriate to not include that pH reduction in the sparge water calculations. Only use the acid's contributions.

PS: Yes, this response did make my brain hurt!
 
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bae388

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Martin,

Thank you so much for your response! Your posts in this thread and throughout the forums has taught me so much! Your willingness to help does not go unappreciated!
 

Kaiser

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A more appropriate way to evaluate the concentration of bicarbonate neutralized is to look at the difference in the starting and ending alkalinity. Say you are at 152 ppm alkalinity as CaCO3 and you want to end up at 25 ppm. That is a reduction of 127 ppm alkalinity. 1 ppm alkalinity (as CaCO3) is equal to 1.22 ppm of bicarbonate neutralized. So the bicarbonate neutralized by the sparge acidification is 127ppm x 1.22 = 155 ppm bicarb (-155 ppm bicarb). Since lactic acid is monoprotic, that means that 155 ppm of lactate is added to the sparging water when neutralizing that much alkalinity.
This calculation is not quite correct. To neutralize 1 ppm alkalinity you need 0.02 mEq/l acid. And since lactic acid is monoprotic as you said you need 0.002 mmol/l lactic acid. with a molar weight of 90 g/mol you need 1.8 mg/l lactic acid (that's also the amount of lactate you'll get) to neutralize 1 ppm as CaCO3 alkalinity. For 100 ppm alkalinity this would be 180 mg/l lactic acid.

Kai
 
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bae388

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Kai,

Thank you for your response! I updated my spreadsheet.

This leads me to another question....

Using your 1.8 mg/l, I figured out that the total lactate ppm from my mash and my sparge (total water) is 198. Is the lactate boiled off during the boil? If not, would the entirety (or most of it) still exist in my boiled wort? The taste threshhold is 200-400ppm... If my lactate content is 198ppm in 10.17gallons of initial water, I figured I would be fine. However, after mash and boil-off I'm left with about 6 gallons. Anyways, is the taste threshhold based on the initial water or what's left after boil-off? There are so many factors that seem to come into play here, it's sort of overwhelming.
 

Kaiser

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I think it is more practical to express the lactate as lactate per grain weight. With that approach you don't have to worry about boiling (which does not boil off lactate) concentrating your lactate. Furthermore it takes into account that more grain per water usually means higher gravity and with a higher gravity the lactate taste threshold should increase.

There is a general rule of thumb that one should not use more than 5 % acidulated malt. That's why I think its useful to express lactate as equivalent percent of acidulated malt used.

When it comes to the taste threshold of lactate, I haven't seen much data except for a few rules of thumb here and there. But those rules seem to make sense, though.

Kai
 

mabrungard

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Sorry, but no. Lactate per grain weight would not be a good measure. I'm afraid I am not following Kai's logic above. The argument based on a percentage of acid malt is dubious at best.

A little more research might have been wise before commenting on lactic acid taste threshold. I pulled out my copy of Malting and Brewing Science and found a published reference. Fortunately for Kai, he can just Google 'lactic acid taste threshold' and he will be whisked to page 849 in that book via the courtesy of Google.

Additionally, the fermentation by-products of yeast include lactic acid. Some yeast are more prolific than others at producing acidity, so I assume that some have varying degrees of lactic acid production. That is why its important to limit lactic acid additions to create something less than 200 ppm to avoid most people's taste thresholds. That still could leave a person that is sensitive to that taste, disappointed. In the OP's case, I'd seriously consider moving to phosphoric to avoid the effect all together.
 
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bae388

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Thank you both for the help once again.

I will consider using phosphoric acid for my next batch. In fact, i'll probably just dillute it a little more and add more salts. However, I used lactic acid in the batch I just brewed yesterday.

I'm trying to keep this as simple as possible, while keeping the taste threshhold in mind. I found somewhere (probably in these forums), that 400ppm of lactate per gallon is approximately 1.25mL of lactic acid. As Kai said, lactic acid is not boiled out, so the amount of acid I used in my total starting water would be carried over to my fermenter. Thus, if 400ppm of lactate in a 5.5 gallon batch (to my primary) is approximately (1.25mL * 5.5=) 6.875mL, and I used 4.09mL of lactic acid in my total water, I would end up with roughly (4.09mL / 6.875mL * 400ppm) = 238.06ppm. I don't know how accurate this is, but if it gets me in the rough ball park it will work for me. So, I'm a little over your recommended limit Martin, but hopefully it comes out ok.
 

Kaiser

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A little more research might have been wise before commenting on lactic acid taste threshold. I pulled out my copy of Malting and Brewing Science and found a published reference. Fortunately for Kai, he can just Google 'lactic acid taste threshold' and he will be whisked to page 849 in that book via the courtesy of Google.
Thanks for that pointer. I took a look and it only mentions a taste threshold of 400 ppm for lactic acid. No mention of the source or if there is a dependency on beer strength. Given that this book is targeted towards large commercial brewers i assume that this number is for regular strength (12 P) beers. Your limit of 200 ppm for lactate added during brewing makes sense and comes out to about 4% acid malt for a 12 Plato beer brewed with good efficiency.

But nothing here is an argument against reporting the added lactate on a per grist basis.

I think either way will work for brewers as it keeps them away from adding too much lactic acid.

On a side note, I also checked Narziss' Technologie Der Wuerzebereitung and while he does not mention a taste threshold he mentions Sauermalz additions as high as 8%, which I find a bit high.

Kai
 
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