pH Problem?

[ajdelange]

As suggested earlier the best thing to do is remove as many variables as possible. A potential major one here is temporal variation in the water's alkalinity. This can easily be removed by removing all the alkalinity which is simply done by titrating the water itself to mash pH. A much simpler approach is to realize 0 alkalinity water by using RO water. Add calcium salts in equal amounts to the extent of perhaps 2 mEq/L each of sulfate (96 mg/L) and chloride (70 mg/L). This will give you 3 mEq/L (60 mg/L) calcium total which is plenty. You will adjust the sulfate and chloride levels upon tasting the finished beer adding more or less of each dependent on whether added sulfate/chloride improves it or degrades its flavor.

To hit pH 5.4 with the proposed grist you will need about 3% sauermalz (6 Oz) but this is an estimate based on malts similar to the ones you are using as I don't have data on the actual ones you are using. With the popular brewing spreadsheets you get errors from modeling the malts by their colors which is clearly inadequate but gets you a ballpark number in most cases. In my calculations you get errors from modeling your malts as ones that I or others have measured which is clearly inadequate but gets you a ballpark number in most cases. This is why it is so important to do a test mash.

 

[dmcmillen]

How about distilled water? I don't have a source for RO water where I live. I believe ro water has a ph of 5 - 6 and distilled water 7.0 so how much acid would you suggest. Also, I currently do not have any acidification malt, so I would have to use lactic acid. What's the ratio of acidification malt to lactic acid?

If I read you correctly, you are suggesting to mash with NO minerals, only acid to see if pH hits close to expected 5.4 and then make additions prior to kegging and carbonating. I suppose I can do this but this is a pepper beer with Jalapenos and Anaheim peppers in the boil and secondary so that may be difficult.

 

[ajdelange]

How about distilled water?

Distilled is fine. It has very low mineral content and that is what we seek. We want all (or at least the vast majority) of the minerals in the water you brew with to be under your control.

I believe ro water has a ph of 5 - 6 and distilled water 7.0 so how much acid would you suggest.

As both are low in minerals (very low alkalinity) both are influenced by the small amount of CO2 in the air and will have pH's in the 5's and 6's.

Also, I currently do not have any acidification malt, so I would have to use lactic acid. What's the ratio of acidification malt to lactic acid?

Acidulated malt is malt as well as containing the acid needed to neutralize base malt alkalinity. There is, therefore, no 1 - 1 equivalence. The sauermalz recommendation I gave was based on an estimate of 57 mEq acid needed for base malt neutralization. As the 88%lactic acid sold by most homebrew shops is 11.4N you would need about 57/11.4 mL. But if your actual base malt is more or less alkaline that the one I used for my calculation (Rahr) then you will need more or less acid so it is important to do a test mash.

If I read you correctly, you are suggesting to mash with NO minerals, only acid to see if pH hits close to expected 5.4

No. I said that if you wanted to stick with your water with its possibly varying alkalinity that you can deal with that variable alkalinity by adding acid until pH 5.4 (or whatever mash pH you fancy) is reached. As this can result in potentially widely varying acid cations in your beers I suggested that starting with 0 mineral (or very low mineral) water is a better way to do things and that if you start with 0 mineral water you should add salts in sufficient quantity to result in about 2 mEq/L each of chloride and sulfate.

... and then make additions prior to kegging and carbonating.

Misunderstanding here too. Two mEq/L each SO4-- and Cl- may give you a beer you like (and very probably will) but there is a good chance you can tune the amounts of these ions to get one you like better. To help you to determine whether to add more or less sulfate and chloride I recommended tastintg the beer made with 2 mEq/L of each and then tasting again with small supplements of sulfate and chloride salts. An improvement in flavor when adding an ion suggests that a subsequent brew might benefit from a bit more of it. A degradation in flavor suggests that it might be beneficial to brew with less of that ion next time.

 

[dmcmillen]

Thanks AJ. Got the misread. Were you estimating based on Rahr Pale Ale because that is the base malt I usually use and would prefer to use.

Can you suggest the parameters for a test mash please. Just the base malt, or all the grains and how much to scale down.

I recommended tastintg the beer made with 2 mEq/L of each and then tasting again with small supplements of sulfate and chloride salts.

What quantity of the beer would you suggest to use? A glass or 12oz would require extremely small additions. Also, pre or post carbonated beer?

Lastly, I'm sure you can tell I'm not a chemist. I am college educated in the sciences. Many people like to use mEq/L which I understand to be milli-equivalent/L or one thousandth of an equivalent weight and the equivalent weight of a substance is the amount of a substance that displaces so much oxygen or hydrogen. First of all, I don't know what that is for say SO4 or Cl nor do I know how to convert to a more useful measurement like mg/L or even ppm. I'm sure you've been trained in and have been doing this for a long time so that you can probably make the conversion in your head, but a layman like myself could use a little help or direction here.

 

[ajdelange]

Were you estimating based on Rahr Pale Ale because that is the base malt I usually use and would prefer to use.

I used Rahr because you said that you used it and I have some data on it. The fact that it isn't the same batch or season as the actual you are using says that there will be an error in the estimate but the fact that it at least comes from the same maltster under the same label says that the error will be smaller than if I used some other pale malt's data.

Can you suggest the parameters for a test mash please. Just the base malt, or all the grains and how much to scale down.

As the goal is to estimate the pH of the actual mash you will achieve the test mash composition should be as exactly the same as that of the full mash but the total amount of grain mashed should be small i.e. a pound or less. Use water treated the same way as the water you will brew with and in the same proportion. Heat it to the strike temperature you plan for and try to hold the mash at something close to the temperature you will hold after strike for 10 or 15 minutes. Then withdraw some of the liquid, cool it to room temperature and measure the pH.

What quantity of the beer would you suggest to use? A glass or 12oz would require extremely small additions.

Most guys seem to make solutions of gypsum and calcium chloride and add drops of them to a glass of beer.

Also, pre or post carbonated beer?

It should be as close to the finished product as you can get it. Clearly stirring in drops of salt solutions is going to disturb the carbonation some so stir gently.

Lastly, I'm sure you can tell I'm not a chemist. I am college educated in the sciences. Many people like to use mEq/L which I understand to be milli-equivalent/L or one thousandth of an equivalent weight and the equivalent weight of a substance is the amount of a substance that displaces so much oxygen or hydrogen.

The concept of equivalence is base on how much of something reacts with something else. Because it is necessary to specify precisely what is reacting with what IUPAC is apparently moving away from this but for this restricted application it is just makes things so simple that I can't resist using it. Here a mEq is simply a mmol of electric charge. If one must add 2 mmol of an acid to neutralize a base malt's alkalinity and each molecule of that acid contributes 2 protons to the process we say we have added 4 mEq of protons as each proton has unit charge. The malt has 4 mEq of excess negative charge at its natural pH relative negative charge at the desired pH. We say it has a 'proton deficit' of 4 mEq. When supplied by the acid, these 4 mEq bring the base malt to the desired pH.

First of all, I don't know what that is for say SO4 or Cl nor do I know how to convert to a more useful measurement like mg/L or even ppm.

Simply take the molecular weight of the substance (e.g CaSO4.2H0 where it is 172) and divide by the charge on the ion in question to get the equivalent weight. CaSO4.2H20 yields 2 mEq of charge for each mmol so its equivalent weight is 172/2 = 86. Each mmol of CaSO4.2H2O yiels 2 mEq of Ca++, 2 mEq of SO4-- and 2 mmol H2O (water isn't charged). So 2 mEq of Ca++ comes from 1 mmol of CaSO4.H2O which weighs 172 mg.

 

[dmcmillen]

but the total amount of grain mashed should be small i.e. a pound or less.

Do you think the .69 gals of underlet volume on my mash tun will be a problem with the test mash?

 

[ajdelange]

If you include it in your calculation of grist to water ratio, use that ratio in the test mash and then make sure that the underlet water is thoroughly mixed in during the actual brewing then the composition of the test and actual mashes should be the same.

 

[dmcmillen]

Been out of town and just getting back to this brew. I'm trying to figure out how to do a small test mash with my equipment. My mash tun is a keggle which takes at least several lbs of grain to even get to the temp probe. A 1 pound (or so) mash would just be some grain scattered over the false bottom. I've got a 9 gallon kettle that I'll have to see if my false bottom with fit in. But even that would be the same diameter as the keggle. Otherwise would appreciate any suggestions.

 

[ajdelange]

Been out of town and just getting back to this brew. I'm trying to figure out how to do a small test mash with my equipment.

You don't do it with your equipment. You do it with smaller containers. A stainless steel beaker in a water bath is ideal but a metal pitcher, saucepan or tin in a larger pot of warm water on the stove top is probably what most brewers use.

 

[dmcmillen]

Thanks AJ. That's the conclusion I came to. Am looking for SS containers that I can use. Just hadn't thought through.