Phosphoric vs Sulfuric/Hydrochloric for liquor acidification

[CharlosCarlies]

Our water is fairly alkaline w/ low/moderate hardness, and we've just been using phosphoric to remove the alkalinity up until now; however, we've been noticing more and more insoluble precipitate in the hot liquor tank with each successive batch (we re-collect our cold liquor back into the hot liquor tank and we're treating all our liquor the same). Is this calcium phosphate or simply calcium/magnesium dropping out from being heated? Whatever it is hasn't seemed to affect the beer yet; however, it is still somewhat concerning and I really would hate to have to occasionally drain off 1200+ gallons of water just to remove something that maybe could have been avoided.

I asked our chemical rep about the possibility of using hydrochloric or sulfuric to avoid this since our water is low in chloride and sulfate anyways. We've been having to augment with gypsum and calcium chloride, so I figured why not kill two birds with one stone? This was his reply:

I received a response on the possibility of food grade Sulfuric and Hydrochloric Acids. We do have both available, and I can provide a quote if necessary. However, these acids are traditionally not used for acidification of brewing liquor. Hydrochloric Acid has the possibility of reacting with water constituents and forming carcinogenic byproducts. Sulfuric Acid has the potential to provide a Sulfur off-flavor to the water.

Does this make any sense? They are normally very knowledgeable, but don't appear very certain in this case.

 

[CharlosCarlies]

And from a safety perspective, I understand hydrochloric/sulfuric can be pretty nasty stuff; however, we have much of the proper safety equipment already and would have no trouble investing in more. From that stand-point, which is worse to deal with?

 

[mchrispen]

With the water in the area, it is more likely a bicarbonate salt. Our calcium levels are so very low that I doubt much calcium phosphate precips.

My water has over 290 ppm Sodium and over 600 ppm bicarbonate, and the faucets are all ganked up with baking soda. And I dredge the white stuff out of my hot tub all the time. You might be able to just vacuum up the precipitate if your tank has a gangway opening, but that would be tricky. Shame that isn't a conical bottom - you could just drop the bottom bit and dispose it.

I think CRS, a UK product is a sulfuric acid solution. AJ or Martin should have a better handle on the specifics.

 

[ajdelange]

Our water is fairly alkaline w/ low/moderate hardness, and we've just been using phosphoric to remove the alkalinity up until now; however, we've been noticing more and more insoluble precipitate in the hot liquor tank with each successive batch (we re-collect our cold liquor back into the hot liquor tank and we're treating all our liquor the same). Is this calcium phosphate or simply calcium/magnesium dropping out from being heated?

I guess you could collect some and drop a little hydrochloric acid on it. If it doesn't fizz then it all probably phosphate. If it does fizz then there is some calcium carbonate in there but it doesn't say there isn't some calcium phosphate (apatite) in there too. If you add a drop at a time of fairly dilute acid and the fizzing stops when there is solid left then that is probably apatite.

Whatever it is hasn't seemed to affect the beer yet; however, it is still somewhat concerning and I really would hate to have to occasionally drain off 1200+ gallons of water just to remove something that maybe could have been avoided.

You should be able to add hydrochloric acid or sulfuric acid when the tank is nearly empty (I'm assuming most of this is at the bottom) or CIP with an acid solution which should dissolve any apatite and then dump that.

I asked our chemical rep about the possibility of using hydrochloric or sulfuric to avoid this since our water is low in chloride and sulfate anyways. We've been having to augment with gypsum and calcium chloride, so I figured why not kill two birds with one stone? This was his reply:

I received a response on the possibility of food grade Sulfuric and Hydrochloric Acids. We do have both available, and I can provide a quote if necessary. However, these acids are traditionally not used for acidification of brewing liquor. Hydrochloric Acid has the possibility of reacting with water constituents and forming carcinogenic byproducts. Sulfuric Acid has the potential to provide a Sulfur off-flavor to the water.

Those acids are traditionally used in adjusting brewing water at least in the UK (http://www.murphyandson.co.uk/datasheets/Data-Sheets2/AMS.pdf) but they have fewer lawyers over there. Yes, chloride can react with organics to produce some nasty things so as a commercial operator you would want to be sure that the water you are adding the acid to is very low in TOC. But how low? Our legal system is famous for making huge awards to plaintiffs on the basis that something might have caused grief even though it cannot be proved that it did cause grief. Wouldn't you need TTB approval as part of your process filing requirements? Would that be enough to protect you? You should probably be seeking legal advice, not chemical.

Sulfate ion is sulfate ion whether it comes from gypsum or is already in the water or is added as acid and yes it is a source of sulfur. Sulfate in the water is responsible for the mercaptan formation in the light strike reaction and for that lovely paper mill smell one encounters during lager fermentation and for junbuket (or at least part of it). I wouldn't consider that a reason not to adjust water chemistry with sulfuric acid.

Does this make any sense? They are normally very knowledgeable, but don't appear very certain in this case.

Given the CYA nature of modern American life, yes.

 

[reuliss]

Phosphoric causes calcium to precipitate. Why not try lactic?


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[ajdelange]

Phosphoric only precipitates calcium if the water is very hard (see the charts in the back of the Water book if you have it). Phophoric is very desirable because it is flavor neutral to a greater extent than any of the other commonly used acids.

 

[And1129]

And from a safety perspective, I understand hydrochloric/sulfuric can be pretty nasty stuff; however, we have much of the proper safety equipment already and would have no trouble investing in more. From that stand-point, which is worse to deal with?

Just considering the concentrated acids themselves, I would probably go with Sufuric acid over the hydrochloric. Both are strong acids which is nice because you will not need to use as much volume to have the same effect as with a weaker acid such as lactic and both are mostly flavor neutral. Concentrated hydrochloric acid is actually a gas that is dissolved into solution with water, so it puts off a lot of nasty HCl vapors when it's opened, used, and poured; especially if in a warm environment. Also concentrated hydrochloric has the potential to react with certain metals to produce hydrogen and chlorine gas, both of which are dangerous, if not handled properly. Sulfuric is still a very strong acid and it is a dense viscous liquid in concentrated form, but it doesn't have a high vapor pressure like HCl does. As always, don't let MSDS info scare you too much, but do do your homework on whichever you will be handling. Also for some beers you may want to raise the sulfate level, and I can't think of a single time where i've necessarily had to adjust my chloride level up, but maybe that's just my water. Good luck in whatever you choose! Acids are fun!

 

[ajdelange]

While I agree that a snootful of HCl gas is most unpleasant I guess I'd vote for concentrated sulfuric as the nastiest based on its affinity for water. Pour a little over some sugar. Now both are rated 3 for health and both are nasty but I can just picture that H2SO4 ripping the water out of me the way it does out of the sugar. Sulfuric acid would be considered more hazardous based on its reactivity rating of 2 as opposed to 1 for HCl. The health and fire hazard ratings are the same.