A Brewing Water Chemistry Primer

ajdelange · Nov 20, 2010

funkswing said:
There's your problem right there. DOn't use 100% RO water with just a small dose of CaCl2. The mineral profile for your beer is going to be waaaaaay off (not enough minerals) from what it should be (and way off from any beer that is brewed).

A couple of comments on this.

1. Several beers, notably the Bohemian Pilsners are brewed with water that is very soft. "Very" is, of course, subject to interpretation.

2. Malt contains quite a bit of mineral - certainly enough to supply co-factor needs for enzymes if not enough to lower pH into the optimum regions.

3. When measuring a malt's extract a Congress Mash using distilled water is employed. Efficiency is calculated relative to the extract obtained from the Congress Mash. As no efficiency tops 100% it's clear that we cannot obtain in our own brewing efficiency as good as is obtained with distilled water. Conclusion: using very soft water doesn't have much of a detrimental effect on mash efficiency.
4. Most RO systems have rejections in the 90's. Thus if water has a nominal alkalinity of 100, hardness of 100, chloride of 7... the permeate could be expected to have (assuming 98%) alkalinity of 2, hardness of 2, chloride of 0.14 etc.

5. I am finding that the softer the water I brew with the better the beer turns out. I haven't formally gone public with this finding because I want to continue this line of experimentation further and I am a lager lout. IOW I don't brew many ales other than Kölsch and Weizen. It seems to work for them but I really don't know how traditional British ales would be perceived if I cut way back on the sulfate in them.

funkswing · Nov 20, 2010

AJ - I like the info, but no one is talking about mash eff. here. And regardless, mash eff. has little to do with the taste of the beer (unless you are at extremes), which is the point of the water chemistry primer: to improve the taste of your beer.

I am finding that the softer the water I brew with

This is a relative statement, with the relative part left out. What is "softer"? What is the water profile of said "softer" water? This is also subjective you lager-loving, fool.

"Very" is, of course, subject to interpretation.

The only interpretation needed is a water profile analysis sheet.
Very soft water still has more mineral than RO water does (but I guess that RO water has a bit of a range of mineral content based on the eff. of the RO process).

I wouldn't brew any beer with 100% RO water. But you could if you dosed it with the right amount of salts/minerals (but this seems unnecessary)

ajdelange · Nov 20, 2010

The sticky doesn't say "for lager add CaCl2 to the softest water you can get" because I'm not ready to conclude that does make the best lager at this point though it looks as if I might come to that conclusion eventually.

I have been using RO water with a bit of tap water (pretty nominal stuff) and reducing the tap water over time. The beers just seem to be getting smoother and smoother and richer in flavor but I have not done 100% RO water yet. I do add enough CaCl2 to get to about 25 ppm or so whatever the dilution.

What "soft" means here seems to depend on the mood my RO system is in. I'm almost serious but I really think it has to do with temperature. My feed water seldom exhibits TDS above 160 and the permeate usually runs 3-4 but can read as low as 0 (I don't believe it - it's instrument noise/quantization) or as high as 5 i.e. pretty soft.

bgough · Dec 6, 2010

If I take a mash PH reading, and it is too high, ho0w much lactic acid would I need to add in order to get it into range? Is there a formula or equation?

remilard · Dec 6, 2010

bgough said:
If I take a mash PH reading, and it is too high, ho0w much lactic acid would I need to add in order to get it into range? Is there a formula or equation?

Depends on a number of factors and can't be predicted exactly.

With acid malt, 1% of the grist is supposed to reduce pH by a 0.1 and it's reasonably close to that in my brewery.

On the brewing network forum AJ started from there and the fact that the lactic acid content of acid malt is known and calculated that 0.875 ml of 88% lactic acid solution (what hombrew shops carry) should decrease pH by 0.1 approximately for 10 lbs of grain.

Since this is all very approximate, it may be worth measuring out the amount that should give you half of your desired pH shift, wait a few minutes, measure pH and then add part, all or more than all of the other half based on how much shift you got out of the first addition.

On brewday I would rather measure out 4 oz of acid malt than a fractional ml of acid so I just use the malt. Buying the acid is quite a bit cheaper but I am using maybe 10 lbs of acid malt a year and in most cases I can predict when I need it so I am replacing base malt with it anyway (in the case that I measure and then add it, a few ounces in 5 gallons doesn't materially affect the gravity). So, at the end of the day, I don't see the downside of the acid malt.

HoozierDaddy · Dec 9, 2010

Yooper said:
By Ajdelange

For British beers: Add 1 tsp gypsum as well as 1 tsp calcium chloride

For very minerally beers (Export, Burton ale): Double the calcium chloride and the gypsum.

This would be for each 5 gallons treated right? So if I want to treat 10 gallons at once for an english pale I'd add a grand total of 4 tsp calcium chloride and 2 tsp gypsum?

ajdelange · Dec 9, 2010

Correct

SC_Ryan · Dec 29, 2010

So the difference between RO and distilled (for brewing purposes) is just that distilled has fewer minerals?

ajdelange · Dec 29, 2010

In essence, yes. RO water will contain ions at a level 95-99% lower than the feed water. Distilled or otherwise deionized water will have ion content even less than that - down to 10^-7 moles/L H+ and 10^-7 moles/L OH- for the really pure (18 Meg-ohm) DI water.

ajdelange · Jan 9, 2011

Was that measured with a meter or strips? What temp?

RonRock · Jan 25, 2011

Is there a guideline as to the upper limits of sauermalz and lactic acid one would want to add?

ajdelange · Jan 25, 2011

3% sauermalz is subtly beneficial to flavor without any suggestion of sourness whatsoever and I believe Weyermann has on its website a recipe for a Berliner Weiße that calls for 8% (IIRC) so clearly there is some sour perception there. I guess I would not go above 4% without trepidation. As always, your best answer will come from experimentation.

jeffmeh · Jan 25, 2011

First, let me say that the instructions in the original post are very clear. The only ambiguity I saw was,

"For British beers: Add 1 tsp gypsum as well as 1 tsp calcium chloride"

This was clarified later in the thread, and, if I understand it correctly, this is in addition to the baseline that already adds 1 tsp calcium chloride, so it would total 2 tsp calcium chloride and 1 tsp gyspsum. It may make sense to edit the original post to make this completely clear.

The other piece of info I picked up later in the thread is that for 1 tsp we are assuming 5 g. Perhaps the original post should be converted to grams.

Thanks so much for this.

Hermit · Jan 25, 2011

jeffmeh said:
First, let me say that the instructions in the original post are very clear. The only ambiguity I saw was,

"For British beers: Add 1 tsp gypsum as well as 1 tsp calcium chloride"

This was clarified later in the thread, and, if I understand it correctly, this is in addition to the baseline that already adds 1 tsp calcium chloride, so it would total 2 tsp calcium chloride and 1 tsp gyspsum. It may make sense to edit the original post to make this completely clear.

The other piece of info I picked up later in the thread is that for 1 tsp we are assuming 5 g. Perhaps the original post should be converted to grams.

Thanks so much for this.

I'm pretty sure it is one of each. Calcium chloride for the baseline PLUS one of gypsum if you wish to accentuate hope bitterness. Yooper posted the sticky from her account so AJ can't do a direct edit.

Yooper · Jan 25, 2011

Hermit said:
I'm pretty sure it is one of each. Calcium chloride for the baseline PLUS one of gypsum if you wish to accentuate hope bitterness. Yooper posted the sticky from her account so AJ can't do a direct edit.

No, but if AJ wants me to edit the post, I'll certainly be willing! I am LOVING this water chemistry primer.

I also appreciate that it's not called "Water Chemistry for Dummies"! This is still quite a bit over my head, but the light is going on mroe and more for me and my last beers, brewed a couple of weeks ago, are definitely "shining" more than before.

One question- I saw a question about the max % of sauermaltz recommended before flavor changes occurred. I also saw the question about lactic acid. I have never used lactic acid to adjust mash pH but one of my friends does. At what point do you get a flavor from the lactic acid?

CPooley4 · Jan 25, 2011

I'd certainly like clarification on those questions if possible. My assumption was that for British/Pales we were to add 1 tsp of each (gypsum and cal chl). Also, I've been assuming a tsp of gypsum = 4 grams while a tsp of cal chl = 3.4 grams. Those figures were given in Palmer's book so that's what I've been using personally and what I've given as information in my brew chart. If we're supposed to be assuming something different I'd love to know so that both myself and anyone using my brew chart have the best available info.

Thanks.

cp

Hermit · Jan 25, 2011

CPooley4 said:
I'd certainly like clarification on those questions if possible. My assumption was that for British/Pales we were to add 1 tsp of each (gypsum and cal chl). Also, I've been assuming a tsp of gypsum = 4 grams while a tsp of cal chl = 3.4 grams. Those figures were given in Palmer's book so that's what I've been using personally and what I've given as information in my brew chart. If we're supposed to be assuming something different I'd love to know so that both myself and anyone using my brew chart have the best available info.

Thanks.

cp

I'm pretty sure AJ has said that the amounts aren't super critical. Think about it. This is just a starting point and doesn't take grain bill into account. In the end, this is cooking and everything is done 'to taste' so to speak. This is where science and art start to merge. You can always just take a teaspoon and measure one out on your scale.

CPooley4 · Jan 25, 2011

I get that and agree. However, if his assumptions are easily available I'd like to have the correct assumptions is all.

By the way, I wish I was from an alternate universe sometimes myself

ajdelange · Jan 25, 2011

The intention was that it would be 1 tsp (5 grams) calcium chloride as the base line. If you wished to emphasize hops (as you would in many British styles) you would add 1 tsp of gypsum in addition to that original tsp of CaCl2.2H2O for a total of 1 tsp of each. But it then goes on to say for minerally beers (such as Burton ales) that you should double the salts (2 tsp of each).

CPooley4 · Jan 25, 2011

Thanks AJ, really appreciate it.

Are you then assuming 5 grams per tsp of Gypsum as well?

funkswing · Jan 25, 2011

5 grams Gypsum is more like 1 TBL, not 1 tsp. But I wouldn't measure like that, its well worth the $10 on ebay for Digi's.

OK, I weighed it out:

1 tsp gypsum = 3 g
1 TBL " " = 9 g

CPooley4 · Jan 25, 2011

I've gotten 4 grams when measuring on my digi scale for gypsum. Probably depends upon whether you're doing a rounded tsp or straight tsp. Still good to know what AJ's assumptions are for his water profile recommendations so we can all adjust accordingly with the EZ Calc or whatever program you're using.

ajdelange · Jan 25, 2011

Calcium chloride is in nice little spheres which pack together pretty uniformly. Gypsum, by contrast, is fluffy so you will have variation according as to how tightly it is packed and how "level" the teaspoon is. Just sticking a teaspoon into the jar and dumping it onto the balance without much regard for leveling (but you certainly couldn't call it heaping) I got 6 grams. A carefully leveled teaspoonful from the same jar came in at 3.6 grams.

It really is better to weigh it out.

kjbatt · Jan 25, 2011

Ajdelange,

Thanks for the response. I was able to calibrate my ph meter so, thankfully, I didn't mess that up! I guess I misunderstood the add 1 and double for hoppy beers...

I brew my IPA frequently so i will try again and scale back on my additions.

CPooley4 · Jan 25, 2011

Thanks aj. So for your water recommendations is it safe to say you are assuming 5 grams for gypsum?

Also, are you considering apa and ipa in the British category or minerally beers category for you recommendations?

DeafSmith · Jan 26, 2011

Looks like Kai has a new addition on his web site (at least I haven't seen it before) - an easy to visualize model of pH buffers:

http://braukaiser.com/wiki/index.php/A_simple_Model_for_pH_Buffers

Lots of other interesting info. over there, too.

SpanishCastleAle · Jan 31, 2011

I'm just now getting to 'post-fermentation' with some of my beers since acquiring a pH meter and using this primer (although I haven't tasted any of them yet, a con of having a pipeline I guess). I've noticed that my post-fermentation pH is a little lower than expected. With a pre-fermentation pH of 5.45-ish I'm getting 4.2-ish after fermentation (using sauermalz in mash). There is a comment in one of Kai's pH articles about really soft water not having enough buffering ability so the yeast take the pH too low. I am using a high % of RO (80% up to 95% for yesterday's Boh Pils) because it seems I have to in order to get good pH without using a ton of sauermalz.

Is this anything to be concerned about (and is it normal)? Using mostly RO and sauermalz it seems I'm trying to decrease the buffering ability (so the sauermalz and roast/crystal malts can reduce pH enough) but then post-boil it appears that I may need more buffering ability. Would adding a very small amount of CaCO3 at the end of the boil help? Would it counter any sourness perception?

Lastly, is the ability to reduce pH during fermentation yeast strain dependant? Do certain strains do this better than others?

ajdelange · Jan 31, 2011

SpanishCastleAle said:
I'm just now getting to 'post-fermentation' with some of my beers since acquiring a pH meter and using this primer (although I haven't tasted any of them yet, a con of having a pipeline I guess). I've noticed that my post-fermentation pH is a little lower than expected. With a pre-fermentation pH of 5.45-ish I'm getting 4.2-ish after fermentation (using sauermalz in mash)...
Is this anything to be concerned about (and is it normal)?

Entirely normal and the sign of a healthy ferment. Most finished beer comes in between 4.2 and 4.8 with the lagers generally in the upper part of that range and the ales generally in the lower. Some ales and, of course, sour beers, will have pH less than 4.2. Lagers above 4.8 doubtless exist but I'd be concerned if pH got that high in one of mine.

SpanishCastleAle said:
Using mostly RO and sauermalz it seems I'm trying to decrease the buffering ability (so the sauermalz and roast/crystal malts can reduce pH enough) but then post-boil it appears that I may need more buffering ability. Would adding a very small amount of CaCO3 at the end of the boil help? Would it counter any sourness perception?

Yes, the object in using low mineral water is to get rid of carbonate thus lowering the buffering capacity (alkalinity) of the water so that the lactic in the sauermalz can effect a pH shift but no, you don't need to replace that as your beer pH is falling in the right place. Now if it is a lager that is coming in at 4.2 we might scratch our heads a bit but there are those that would add acid to your kettle to get knockout pH down to 5 - 5.2. I'm not advocating that for now - wait until you taste the beers. Acid in the kettle might be something to try at a later date when fine tuning recipe/procedure.

SpanishCastleAle said:
Lastly, is the ability to reduce pH during fermentation yeast strain dependant? Do certain strains do this better than others?

Yes. That is, I assume, why lagers tend to come in at pH higher than ales.

ajdelange · Jan 31, 2011

Last brew day I took mash pH vs temperature measurements to try to verify the commonly published shift amounts. In a sample from the protein rest I found a shift of -0.0057 pH/°C and from mashout, -0.0052. Averaging those would give -0.0055. I'm not advertising this number as any more than what it is - the number I got using RO water with Weyermann's floor malted Pils with some carafoam and sauermalz in one brew on one day.

Anyway calling room temperature 21°C and assuming mash temperature of 65°C (149°F) the shift would be 0.242 which is a little lower than the 0.3 that is commonlu thown out so that 5.47 would map to 5.23.

jeffmeh · Jan 31, 2011

-TH- said:
Is that 5.47 at room temp? Then the pH at mash temp would be what - say 5.3 ish?

That's a good question. I was assuming that I would be taking a reading at room temp and expecting 5.47. Is that correct?

A Brewing Water Chemistry Primer

Help Support Homebrew Talk:

Supporting Member

Well-Known Member

Supporting Member

Well-Known Member

Well-Known Member

Supporting Member

Supporting Member

Well-Known Member

Supporting Member

Supporting Member

Always Ready

Supporting Member

Well-Known Member

fuddle

Ale's What Cures You!

Well-Known Member

fuddle

Well-Known Member

Supporting Member

Well-Known Member

Well-Known Member

Well-Known Member

Supporting Member

Member

Well-Known Member

Supporting Member

Well-Known Member

Supporting Member

Supporting Member

Well-Known Member

Similar threads