What volume of water do I add salts to?

[ajdelange]

If your water is like that furnished by most municipalities in the US it won't be necessary to do anything separate to the sparge water. If you have a question about this or even if you don't you would do well to check on the situation WRT your particular water. In order to do this you need to record runoff pH and gravity. If the pH gets above 6 before the gravity gets below, say 4 -5 °P then acidification will be necessary. A meter is required to check runoff pH but if I can convince you to buy a pH meter based on checking sparge water pH I'm happy with that. Given that runoff is much more dilute (WRT barley material) I wonder if the strips might work in this application.

I guess I should mention that I don't brew exclusively with RO water. Sometimes I use my well water (very nominal ~ is that a legitimate phrase?) and sometimes (though not usually) I will increase the alkalinity of the well water in order to emulate a profile. Even in those cases pH has always stayed below 6 for me down to the point where I terminate collection. Your equipment, procedures and water will be different so it is always a good idea to do a check. It is because of checks done over the years that I know I don't have a problem with this.

[mthhurley]

I did my first adjustment batch last weekend and I did it somewhat "wrong" per Brew Strong (figured this out afterwards).

I started with RO water and added Gypsum, CaCl and Epson to get to an IPA'ish profile. However, I dumped it into the water as I was heating it up for the mash. I noticed when draining it to the mash tun to start the mash in a whole lotta white powder at the bottom that did not dissolve. Hopefully I stirred it up enough and got it into the mash where it was handled when the pH dropped.

However I did the same treatment to the sparge water as it was heating, same result, some white leftovers.

So mabrungard, if I did not add any chalk (CaCo3) to my RO water, what was I seeing undissolved in my pots?

[JohnF]

You must not have stirred well enough. I have no problem dissolving reasonable amounts of gypsum and calcium chloride and I dough in with water at around 110F. You do have to stir it in (or wait a long time I guess).

[ajdelange]

I started with RO water and added Gypsum, CaCl and Epson to get to an IPA'ish profile...

So mabrungard, if I did not add any chalk (CaCo3) to my RO water, what was I seeing undissolved in my pots?

Calcium sulfate isn't considered highly soluble though the solubility of ~ 2 grams/L would seem to be pretty high to a brewer. If you added amounts approaching 2 g/L you might expect that it wouldn't all dissolve. If it did all dissolve but the solution was near saturation the extrea sulfate ion from the Epsom salts and extra calcium from the CaCl2 could push the ion product past the solubilty product causing precipitation to occur. Also, some of the forms that can precipitate are less soluble at higher temperature but you would still have to have put a whole lot in to see precipitation even at high temp.

Thus the white stuff is either calcium sulfate which never got dissolved or calcium sulfate which precipitated but I'm troubled by the fact that you would have to add so much to see this. How much of each salt did you add?

[mthhurley]

Thus the white stuff is either calcium sulfate which never got dissolved or calcium sulfate which precipitated but I'm troubled by the fact that you would have to add so much to see this. How much of each salt did you add?

I did the mash with 4.5 gallons of RO water, all these measurements are in grams/gallon. 1.6 grams/gallon of gypsum, 0.7 Epsom, 0.1 CaCl2

[ajdelange]

1.6 grams of gypsum should easily dissolve in a liter of water so you are far from approaching saturation if you put it in a gallon. And those other additions are not sufficient to get you near saturation by common ion effect either. I am, thus, mystified. I have no idea what the precipitate would be unless the RO system failed somehow and passed bicarbonate and, as an explanation, that's a bit of a reach.

[Junket]

Here's how I've been prepping my water, with good results:

I start with Reverse Osmosis water and I formulate recipes for low-efficiency/no-sparge, removing the need to worry about the pH of my sparge water/runoff. I calculate the desired mineral additions in grams per gallon based on a published water profile, recipe, or my past experience. Then I add up the volumes of all mash infusions that occur before mash-out (if any), giving me "Mash Water Volume". Then subtract Mash Water Volume from desired total pre-boil volume (7 to 7.5 gallons for me depending on boil time) to get "Kettle Water Volume". Multiply MWV and KWV by the grams per gallon numbers, and I know the proper salt additions for the batch.

The mash additions are added to the milled grain, not to the water - I figure that this will help to get the salts mixed in and disolved. The kettle additions are added at the beginning of the boil. Any necessary sparge water and dilution water is just straight RO.

I'm hitting perfect mash pH every time - which is my primary goal for water treatment.

But here's the interesting part; my exploration of water treatment has pushed me to refine my process in ways that are "seemingly" only tangentially related to the actual goal of hitting water profiles:

I've finally accepted that there's absolutely no logical reason to ever "miss your gravity", because I'm monitoring gravity and volume during runoff and using Beersmith's dilution tool to determine how much water to add to hit both Pre-boil Volume and Gravity. There's no need to try to hit your gravity AND volume without monitoring and tweaking.

By calculating at a low efficiency, I might be using an extra $3-5 of grain, but I'm always coming up with enough sugar in my extract, and don't need to worry about the possibility of a high pH sparge. Ideally, I get a high enough runoff gravity that I'll need to ADD water to the kettle to LOWER my gravity to the target rather than sparge to get more sugar.

I'm sure I'll continue to tweak my process as I continue to learn, and that I'll look back at my current logic and realize some oversimplifications or overcomplications, but that's what makes experience so important in brewing.