Water chemistry help

[Jtvann]

I am wanting to get into water chemistry. I have recently purchased a countertop RO system. I think I understand all of the chemistry behind calculations of salts and minerals.

I’m not sure on when to add the various additions. If I’m mashing in with 4.5 gallons of water, should I add 100% of my minerals and salts to the mash water while I’m heating it to strike temp?

Assuming RO water, I don’t need to worry about lowering the pH for sparging.

My question was really whether to add 100% to the strike water, or do I vary it in amounts between the strike and sparge water.

 

[Rob2010SS]

Short answer to your question is you would add it to both your strike and sparge water. Highly recommend using Bru'n Water (which can be found if you just google it). You enter your grain bill and your starting water chemistry and it will tell you how much of each salt/mineral to add to both sparge and mash water.

You won't need to worry about pH of sparge water but you will still need to add the minerals/salts.

I have heard of people adding back about 30% of the minerals after the mash is complete and they've lautered to the boil kettle. I have not done this but I've heard of others doing it. The thought is that you lose about 30% of the minerals added to the grains in the mash. No idea if that's accurate or not. I would simply stick to adding it to the mash water before doughing in and to the sparge water.

 

[Jtvann]

Thanks for the reply. I’ve downloaded both bru’n water and EZ water calculator. Trying to play a little bit with either of them.

I do actually have a chemistry degree. The chemistry behind all this is pretty easy. Figuring out how to use the programs will take me more time.

 

[micraftbeer]

I concur. One thing you can run into if you try to put the salts for your mash + sparge into just your strike water is solubility of the salts. You want them to mix into the water and not be a residue sitting at the bottom.

Adding the minerals post-mash seems strange. Salts can affect flavor all on their own and of course mouthfeel. But they're largely intended to be there for the proper chemistry during your mash. So who cares if it gets sucked up and stuck with your spent grains?

 

[Rob2010SS]

I concur. One thing you can run into if you try to put the salts for your mash + sparge into just your strike water is solubility of the salts. You want them to mix into the water and not be a residue sitting at the bottom.

Adding the minerals post-mash seems strange. Salts can affect flavor all on their own and of course mouthfeel. But they're largely intended to be there for the proper chemistry during your mash. So who cares if it gets sucked up and stuck with your spent grains?

Completely agree with you @micraftbeer , I thought this was strange myself. It was a group of brewers in Sweden actually. Other than them, I've never heard of anyone else doing that.

 

[GPP33]

Adding the minerals post-mash seems strange. Salts can affect flavor all on their own and of course mouthfeel. But they're largely intended to be there for the proper chemistry during your mash. So who cares if it gets sucked up and stuck with your spent grains?

The minerals are dissolved in the water so they'll be soaked up at the same rate as the water, you need to add more minerals when you add fresh water but that's already dissolved in the sparge water. I agree that adding even more seems strange. Maybe they didn't add it to the sparge water?

 

[Jtvann]

Ok ... so I’ve got a few replies here looking into helping me. Someone please plug my numbers in and see if I’m working this right.

I’ve purchased a RO system. I’m going to assume zero TDS, but that’s a total assumption. Even if I have say 10, I’m going to treat it as zero, cause I’m not going to send water off to test that small of an amount. I’ve also purchased a decent pH meter, but neither it nor the RO system is here yet. So the toys are coming and I’m hoping to figure out the hypotheticals beforehand. For now I’m assuming pH 7, but figure in reality it will be lower.

I plugged my numbers into bru’n water ... and this is what I’d like reviewed to see if I did it right. I’m building an IPA, using the preprogrammed numbers from the pale ale profile.

My recipe is:
10lbs 2 row
1.5 lbs Munich 10L
.5 lbs Crystal 60L
.5 lbs Carapils

I’m aiming for a 6 gallon batch, using 4.7g strike water and 4.5 sparge.

Targeting
Calcium - 140
Magnesium - 18
Sodium - 25
Sulfate - 300
Chloride - 55
Bicarbonate - 110

Using the following for mash / sparge
Gypsum -8.5g / 8.1g
Calcium Chloride - 1.4g / 1.4g
Epsom Salt - 1.9g / 1.8g

Supposedly this gives me the following

Calcium - 139
Mg - 10
Na - 0
Sulfate - 307
Cl - 51

Am I on the right track with given assumptions in how I used the program. I’m well aware that I’m making quite a few assumptions that will change when the real numbers are tested.

 

[ESBrewer]

The logic behind minerals may sound easy but in fact it is quite complicated and everything just can't be totally controlled by calculations made on computer. There are a lot of interactions between ions depending on the exact additions and the mash conditions. As Rob2010SS mentioned, quite a bit of minerals (especially Ca2+) will be lost during the mash and depending on the water, some may be lost already when heating the strike water if there is a lot of alkalinity. So it all comes to recipe, you may want to see what works best in practice and stick to that. Ions are certainly important in the wort during the boil as well as in the final beer product. They affect the taste directly, they affect the chemical properties of the wort and beer and they also interact with several biological compounds found in the malt. But it is not easy to calculate exactly how much ions there will be in the beer because certain ions (especially Ca2+) tend to sediment in the strike water, in the mash tun, during the boil and even later in the process. Fortunately, calcium is not so critical for the taste in the final product (I think), but it is important in many steps during the process and may affect the outcome depending on how much calcium is present post mash.

I have noticed that several breweries actually add solid salts to mash tun while mixing the grains and strike water. They also calculate the salt additions per kg grains rather than liters of beer/water, although these values are connected in a certain recipe. In my first couple of batches I mixed everything with strike & sparge water, but in the latest batch (that tastes & looks the best for many reasons) I only put salts in the tun and it works great. But in sparge water, you generally want to remove the residual alkalinity. Notice that the acid you use for adjusting sparge pH may react with the ions in the wort causing them to drop (e.g. as calcium phosphate when adding phosphoric acid). This may further reduce the concentration of ions in the post mash wort. Salt additions do not have that much effect in the sparge water anymore (and especially so if you added a bit more in the actual mash/strike water). So it is definitely possible to put salts in the mash tun or strike water only. When you mix the hot mash carefully, salts will definitily dissolve (given that they are soluble under those conditions).

 

[mabrungard]

I see that you've elected not to include any alkalinity in your mashing water. With the large dose of calcium salts, its undoubtedly driving the mash pH well below 5.4. That can diminish the hop expression and bittering a bit. Using baking soda in the mashing water can help quite a bit in avoiding an excessive pH drop. The little bit of sodium that it adds, is inconsequential to flavor.

 

[Jtvann]

That was a very informative reply. I’m hoping to get a baseline of where to start with my very first attempt at water chemistry, rather than just using tap water.

Hoping someone can help with plugging in numbers above to see if I’m on the right track.

 

[Jtvann]

I was wondering if it was needed. It’s hard to say what I’m actually going to add with as many assumptions as I’m making. I think right now I’m just trying to wrap my head around the bru’n water program itself.

I assumed the ph would be a neutral 7 with RO water, so that’s what I plugged in. I’m actuality, I’m thinking it will be lower.

As is, assuming 7, the mash pH came out to be an estimated 5.22.

 

[Jtvann]

Now I’m even more confused. I changed the pH value from 7 to 5.5 just to see how much baking soda would be needed and the mash pH didn’t change at all.

 

[micraftbeer]

So it all comes to recipe, you may want to see what works best in practice and stick to that. Ions are certainly important in the wort during the boil as well as in the final beer product.

I echo this point. You obviously have to start somewhere, so your calculators are the best bet there. But it is about the end product. I brew with distilled water because our city water is quite variable to my taste buds, and not always to my liking. I ran a mainly simplified approach for a long time, using either a "malt forward" or "hop forward" profile, depending on the beer.

One day I was doing a mash experiment, trying to see what effect my standard salt additions made to mash pH. I had a simple 2-row & white wheat grist. I found the salts made minimal effect to the mash pH, which wasn't all that revealing. But when I tasted those beers, there was a significant difference. The wine grape/apple sweetness I had in my American Wheat Ales that I hated was totally there in my mash with my "malt forward" profile.

Friends/neighbors thought the Wheat Ales were good, but there was some mineral aspect that tweaked my taste buds. So now my default profile is the "hop forward" profile unless I'm trying to do something very region-specific like a Dusseldorf Alt or Kolsch.

A long-winded answer, but I'd say start with a good water salt calculator for your additions, but don't get too hung up if you like or dislike the taste of the resulting beer that maybe others put forward as the "ideal".

 

[Jtvann]

lol, I’m totally on board with everything everybody is saying. I’ve got a degree in chemistry and understand how all these jobs are working together and against each other.

What I don’t have is an understanding on how the bru’n water program works. I’d like to not have to pop out pencil and paper with a calculator and go back to inorganic chemistry.

I’d like some feedback on what I’m doing right or wrong with the actual program so that I can take that “first” step to begin experimenting with.

I mean throwing in 500g of gypsum is a start, albeit a dumb one. I’m trying to be lazy and use these much talked about water calculators, and they’re not making much sense.

 

[Jtvann]

So does the program run an algorithm and tell you how much of each mineral to add or do you have to manually adjust each up and down to get to the final results you’re looking for?

 

[micraftbeer]

I've never used Bru'n water, although I frequently hear it referenced. Do you have BeerSmith? It's got a built-in calculator. You pick a water profile which is a list of about 5 mineral concentrations, and that's your "target". You then enter your base water, which is easy for RO/Distilled. Plug in 0 for all ion concentration. You hit a button that says something like "best match target" and it spits out how many grams of the basic water salts to add.

 

[micraftbeer]

Targeting
Calcium - 140
Magnesium - 18
Sodium - 25
Sulfate - 300
Chloride - 55
Bicarbonate - 110

Can you confirm these numbers are what you're after? I was going to plug it in to BeerSmith to see if it comes out with similar to what you have above, but I'm thinking maybe your Calcium & Magnesium are flip-flopped?

 

[Jtvann]

Yeah, that’s what I’m shooting for. I found what you said is true. Bru’n water gives a ton more info specific to water than BeerSmith, but BeerSmith does the calculation for you.

The minerals I listed was my best guess first stab at minerals to use ... which has a near 90% probability of being wrong.

I’ve now downloaded BeerSmith to use in conjunction with bru’n water.

 

[micraftbeer]

OK, so different calculators probably get results through different combinations, but BeerSmith spits out the following for your 4.7 gal Strike water:

Gypsum 6.8g
Epsom 3.9g
Calcium Chloride 2.0g
Baking Soda 1.9g
Chalk 1.0g

and it says it will result in:
Calcium - 142
Magnesium - 21
Sodium - 29
Sulfate - 299
Chloride - 54
Bicarbonate - 109

And when I plug in your additions you note above, BeerSmith spits out different resulting water profile. So I'd pick a water profile tool and stick with it, working from there rather than trying to figure out why they're different.

 

[Yooper]

You definitely don't want chalk. So cross that off.

Are you absolutely certain you want 300 ppm of sulfate, and that much calcium? It's a LOT of both.

It depends on what you're making, but I find APAs and IPAs with 150 ppm of sulfate (or thereabouts) much more pleasing than most with 300 ppm of sulfate. I would go with less than 100 ppm of calcium. A mash pH of 5.3-5.5 is great, and for IPAs I usually go with 5.35 or so.

 

[Jtvann]

I’d like to try 300. I’ve seen it referenced a few times as good for IPAs. I might not like it. Will experiment with it and see.

 

[Murphys_Law]

You definitely don't want chalk. So cross that off.

Are you absolutely certain you want 300 ppm of sulfate, and that much calcium? It's a LOT of both.

It depends on what you're making, but I find APAs and IPAs with 150 ppm of sulfate (or thereabouts) much more pleasing than most with 300 ppm of sulfate. I would go with less than 100 ppm of calcium. A mash pH of 5.3-5.5 is great, and for IPAs I usually go with 5.35 or so.

I really wish BeerSmith would just delete the chalk addition altogether!

 

[cabron99]

Why is this the first water conversation I've come close to understanding? Thank you, gentlemen!!
Pat

 

[Yooper]

Why is this the first water conversation I've come close to understanding? Thank you, gentlemen!!
Pat

Ahem- “gentlemen”?

 

[Jtvann]

So how many times throughout the mash should I test pH? What volume sample is normally pulled?

I’m assuming once at about 15 mins in, once everything has had chance to equalize. More towards the end of runnings to make sure pH is staying above 6?

 

[Rob2010SS]

Once about 15 mins in and that is it. Any more than that isn't worth it. But from what I've been told, even at 15 mins in, your pH is set and there's not really much you can do with it. The check is really only to show your calculations were right.

 

[Horseflesh]

Look into making a calcium chloride solution. It's easier to use than chalk for dosing Ca. There's a sticky in the brew science forum.

Bru'n Water does not run a calculation to determine dosing... You do have to fiddle with the numbers yourself. It goes quickly after the first time.

 

[micraftbeer]

Why all the hating on the chalk? I've only used it a couple times when trying to match a particular brewing city's water profile.

 

[micraftbeer]

So how many times throughout the mash should I test pH? What volume sample is normally pulled?

Testing mash pH has a lot of opinions out there. I researched it recently while doing some pH meter reviews, trying to discern fact from folklore. This will probably create an explosive response, as I've seen lots of opinions out there on this stuff, but here we go...

1. pH Is not constant with temperature, it varies quite a bit. And there is no universal pH correction factor based on temperature, it is dependent on the chemical make-up of the sample you're testing.

2. If you look at 99% of the expert advice on recommended mash pH, they omit the temperature value that should go hand-in-hand with the pH value they're telling you is best. The one reference I found that provided pH recommendation with temperature was in John Palmer's How to Brew book, where he provided nomographs in a section on water adjustment. In that graph, he lays out target mash pH based on beer color, and notes that it is mash pH measured at room temperature.

3. Most of the pH meters on the market need your sample to be 120F or lower otherwise you damage the measuring element.

4. You want to perform your pH meter calibration in solutions at the same temperature as you'll be measuring your samples. Otherwise you introduce additional error.

5. In pH measurement world, "room temperature" is 77F. Automatic Temperature Correction adjusts for your pH meter's accuracy drift as a function of temperature. It can't "correct" your sample pH to 77F because of #1, above.

6. As a practical matter, as soon as you pull out your wort sample to measure pH, it's going to start cooling down because it's no longer sitting in a ~150F environment. Since your sample pH will be changing with temperature (#1), your pH meter was probably calibrated in solutions at room temperature (#4), and your ATC meter is doing pH adjustments as a function of temperature (#5), your best bet is to just let everything stabilize at 77F and do your reading there. Otherwise you've got a massive moving target.

So your best bet is to take your sample and let things stabilize to 77F before reading it. Yes, that means you won't really be able to make adjustments to pH on the fly, but it gives you data so you can figure out if you want to adjust the next time you do the same mash.

Alternatively, Hanna Instruments makes a pH meter that is capable up to 200F. It's not cheap, but sticking that into your mash you don't have the moving target thing going on. You'd just want to rig something up so that when you do your calibration, you get the calibration solutions up to that same 150F nominal mash temperature.

 

[Jwin]

All well said.
I do three measurements
One ~10 minutes in(I underlet and do 12g no sparge batches, so mashing in takes 10-15 by itself). Another measurement after all the wort is in the kettle.
Another post boil.
Most of this is for nothing more than to document and to have in the event that I need it down the road. I only actively use the first measurement.
The biggest thing is using the data to correct your next Brew day. It's just another part of dialing in the process IMO.
It's also a good indicator/heads up of something went wrong and otherwise unnoticed. (Forget the two pounds of midnight wheat?)