Chemistry for ultradummies question.
Given the following rule:
HCO3 + H3O+ → CO2 + 2H2O
Is there any reason why a lot of bicarbonates in your water would be bad provided you add a sufficient amount of acid?
Depends what acid you use.
Stolen from the internet (don’t judge me if this is not exact):
NaHCO3(aq) + HC3H5O3(aq) → NaC3H5O3(aq) + H2O(l) + CO2(g)
sodium hydrogen carbonate + lactic acid → sodium lactate + water + carbon dioxide
When lactic acid and baking soda react, sodium lactate salt, water, and carbon dioxide gas are formed.
In many cases phosphoric acid is preferred because lactates have more flavor than phosphates, and the malt in the mash supposedly contributes far more phosphate than the acid reaction.
depends how much bicarb . my well water requires crap tons of acid to drop the PH of the mash, and I was picking up flavor from it at that levels.
That’s basically rephrasing my question. Wouldn’t calcium carbonate be the primary source of the carb? And wouldn’t the reaction simply produce Ca, CO2 and H2O? So where does the flavor come from?
It comes from the acid you use. You’re not just adding a bottle of H3O ions. See my post.
Still don’t understand. Lactic acid is just H, C and O. And you start from sodium bicarbonate. But isn’t calcium bicarbonate the main ingredient?
Don’t confuse (and yet I do all the time) permanent hardness (largely from carbonate) with temporary hardness (largely from bicarbonate). Bicarbonate concentrations are relatively easy to manipulate with moderate amounts of acid, which may also cause insoluble salts to form and precipitate. If you are pre-treating your water to remove alkalinity through boiling or slaked lime, you are mostly converting bicarbonate into an insoluble carbonate salt… and removing calcium.
What is interesting is that one of the salts that often precipitates is calcium carbonate (chalk). It is not that soluble… which is also why many folks no longer recommend it’s use in a brewery.
[quote]Is there any reason why a lot of bicarbonates in your water would be bad provided you add a sufficient amount of acid?
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Narvin answered your question however… large amounts of bicarbonate or alkalinity will require larger amounts of acid to achieve the mash pH goal. Phosphoric acid has a much higher noticeable flavor threshold than Lactic acid so you can perhaps use more phosphoric (and thus a more alkaline liquor) without a flavor impact than the same scenario with lactic acid.
Aha, so calcium carbonate reacts with lactic acid to form calcium lactate, which has an unpleasant flavor?
Yes, but lactic can form sodium lactate, magnesium lactate, potassium lactate as well. All of these ions along with calcium are available in the mash. I would not necessarily call the flavors unpleasant, rather just flavors. Some people feel that lactic acid is a more appropriate alternative to acid malt in brewing a German beer for example, as the flavor contribution (if any) would be similar.
I’ve followed Kai’s guidance of no more than …5ml / lb grist, and don’t pick up any flavors. But with my well water , I had to far exceed that. Never tried phosphoric .
Ok thanks! Would anybody happen to know what happens if the acid is phosphoric?
I’d try Citric Acid, personally. If I remember correctly, Calcium Citrate is insoluble, and will precipitate out of solution. Plus it’s available at the LHBS in the wine-making section.
That said it might be better for adjusting strike water then the actual mash where you have any number more compounds floating around.
Calcium phosphate, another insoluble will precipitate. This maybe a concern with liquor with a high expected value of calcium - phosphoric acid will reduce calcium ion.
For a while some people were very concerned about phosphoric acid and what it would do to calcium levels in the mash because of this. If you are using just very small doses (ie. the alkalinity of the liquor is very low), then I suspect it makes little difference. If you are using a burtonized profile and have massive amounts of calcium, then phosphate formation will likely impact the calcium levels.
Back to your question at hand. Hardwick in “Handbook of Brewing” references 50 ppm of carbonate and bicarbonate as required for “good brewing liquor” and if I recall, Martin references <60 ppm alkalinity as CaCO3. This effectively neutralizes the buffering capacity of the liquor in the mash, and dramatically reduces the volume of acid necessary to achieve a desired mash pH. I believe one can properly acidify liquor around 120-140 ppm alkalinity without really bumping into flavor contributions from either acid, but you would need to experiment to decide.
I am really hoping Martin steps in and checks my work - I can be expressing this incorrectly.
I use phosphoric since, at the levels I need to acidify for pale beers, lactic is at my threshold to smell and taste (1mL/gallon of hot liquor).
See I just don’t like mineral acids. Intellectually I’m sure Food-grade citric acid and Food-grade Phosphoric are made via similar industrial processes, but still I’d just prefer something I don’t use as a sanitizer.
Maybe it’s because back in the day I had to work with ClF3 (https://en.wikipedia.org/wiki/Chlorine_trifluoride), and that gave me a more then healthy fear of inorganic compounds. Then again, once I thought launching 1oz blocks of cesium into lakes was fun. Also, I don’t think there is such a thing as over healthy fear of ClF3.
Calcium citrate is plenty soluble in water at the temperatures and concentrations we’re talking about (0.85g/L at room temp). It’s superior solubility is the main reason why it is preferred over calcium carbonate for calcium supplementation.
Citrate has an even sharper flavor than lactate in my opinion. I don’t feel that it has a place in beer, except possibly in a fruit beer that falls a bit flat in flavor (and even then, I’m not so sure),
What’s your water profile look like?
+1
I detect a basic misunderstanding of ionic chemistry. The reactants above do react, but their products remain calcium and lactate ions until their concentrations exceed their solubility limit and they precipitate from solution as calcium lactate. At the concentrations we typically employ, precipitation is not likely.
I also noted a mention that lactate is just H, C, and O. While that is true, that fact is that they are combined into a molecule and are not ions by themselves. The lactate molecule can be an ion. How atoms are assembled into a molecule has profound consequences…take C and N, when they are combined into a CN form (cyanide), they are deadly. They weren’t when they were just C and N.
Citric acid is a chelator in the presence of divalent metals. There are water softening systems that employ citric acid. The Ca does precipitate as calcium citrate and generally can’t create scale on surfaces. However, a small portion of the calcium and citrate remain in solution as ions.
In those cases where brewers use phosphoric acid, high Ca content can cause a precipitation reaction creating calcium phosphate. It can reduce the calcium content of the brewing liquor, but that is not a problem since this reaction does not occur unless the calcium content of the water is already high. Since beer and yeast do not benefit from excessive Ca content in the water, loosing some Ca is not a problem. The concern with using phosphoric acid is a ‘red-herring’ and is not a concern.
My question was more of a theoretical nature. I myself use demi-water for pale beers and dilute my 180 ppm bicarbonate tap water for dark beers, thanks to what I have learned on this forum and by using Bru’nwater. But what I see homebrewers do in Belgium and the Netherlands is simply add lactic acid to their tap water (which typically has 150-250 ppm bicarbonate), and quite high amounts at that. For example, in one APA recipe that won a first price I noticed the addition of 8,50 ml lactic acid in a 14 liter batch. This should be have a negative impact on the beer, right? I was then wondering what exactly causes the off-flavor, and if I understand this thread correctly the flavor “provider” is lactate, which has a flavor threshold of around 400 ppm.