When to add salts and other questions

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brewmeister13

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On my first all grain I missed my target PH by quite a lot. I was shooting for 5.4 and was at 5.8 prior to adding some extra lactic acid. When I looked in my HLT I noticed that a lot of the salts had precipitated out of the water. I was thinking that next time I should just add them directly to the Mash. Here are the specifics of the brew:

9lbs Maris Otter
10oz Vienna
10oz Munich
4oz Crystal 60
1oz Acid Malt

3.6g gypsum
1.2g Epsom Salt
1.3g baking soda
3.6g Calcium Chloride
added to 6 gal RO water to achieve

80ppm CA
5.2ppm Mg
15.2ppm NA
109.1ppm Sulfate
76.5ppm Chloride
40.3ppm Bicarbonate

My other question is, even without the salt additions Bru'nWater predicts a mash PH of 5.5, but mine was 5.8. What am I doing wrong? I took a sample of liquid shortly after doughing in and cooled it to 25C. The meter had just been calibrated that morning too.
 
That’s a ton of salts. The baking soda doesn’t add anything and the Epsom salt is a negative.

I don’t think anything is precipitating out, you’re well within the solubility of the water. It’s probably the gypsum, it’s hard to dissolve.

Using gypsum is a matter of taste, many find it makes the hop flavor harsh. Try it in a glass of beer and see if you like the taste before you use it in a batch.

In general, I think it’s better to add salts in small amounts, increasing it gradually in subsequent batches until you find the sweet spot. I make a pale similar to yours and I use 1g CaCl to increase calcium from 36 to 54. I get pH 5.4-5.5 with moderately hard water.

How are you measuring pH? 5.8 seems unbelievably high for RO with your recipe.

With 100% RO you need some calcium. As for how much, the jury’s still out on that. 50ppm is a common figure, but many have had success with less.
 
Unfortunately the popular spreadsheets don't keep track of treated water pH, CaCO3 saturation etc. When you add sodium bicarbonate in the amount you did to RO water to which you have added gypsum and calcium chloride the pH goes up to 8.3, the water is saturated WRT CaCO3 (especially at higher temperature) and precipitation of chalk becomes possible. That is probably what you saw. Gypsum isn't all that soluble in hot water either but you should not have approached its solubility limit.

Your plan should not be to add the salts to the mash as it is better to add them to the water as it results in more rapid, uniform dispersal, but rather to skip the bicarbonate. Just as it raises the pH of the water, so it raises the pH of the mash and is doubtless responsible for the higher that expected pH. Adding bicarbonate and sauermalz together is like pushing and pulling on something at the same time.

Next time just use the calcium chloride (and some sulfate too if you like but I always recommend starting without it because lots of people don't like it - test its effect in a glass of the finished beer) and a couple of % sauermalz. See the Primer in the Stickies.
 
It’s probably the gypsum, it’s hard to dissolve.

Using gypsum is a matter of taste, many find it makes the hop flavor harsh. Try it in a glass of beer and see if you like the taste before you use it in a batch.

How are you measuring pH? 5.8 seems unbelievably high for RO with your recipe.

I didn't realize gypsum was difficult to dissolve, that's why I stayed away from chalk. Is there anything to do to help it dissolve? I already add it the day before brewing, sometimes a few days, to a gallon of water.

I measure the pH with test strips, just kidding. I use a Milwaukee pH meter that is brand new. I had calibrated it that morning with both 7ph and 4ph.

Unfortunately the popular spreadsheets don't keep track of treated water pH, CaCO3 saturation etc. When you add sodium bicarbonate in the amount you did to RO water to which you have added gypsum and calcium chloride the pH goes up to 8.3, the water is saturated WRT CaCO3 (especially at higher temperature) and precipitation of chalk becomes possible. That is probably what you saw. Gypsum isn't all that soluble in hot water either but you should not have approached its solubility limit.

Your plan should not be to add the salts to the mash as it is better to add them to the water as it results in more rapid, uniform dispersal, but rather to skip the bicarbonate. Just as it raises the pH of the water, so it raises the pH of the mash and is doubtless responsible for the higher that expected pH. Adding bicarbonate and sauermalz together is like pushing and pulling on something at the same time.

Next time just use the calcium chloride (and some sulfate too if you like but I always recommend starting without it because lots of people don't like it - test its effect in a glass of the finished beer) and a couple of % sauermalz. See the Primer in the Stickies.

Thanks for the awesome advice. I'll skid the bicarbonates from now on and focus on the pH. Are bicarbonates only helpful if the grain bill is heavy on roasted malts and the pH would otherwise be too low?
 
I didn't realize gypsum was difficult to dissolve, that's why I stayed away from chalk. Is there anything to do to help it dissolve?
.

It's not that difficult. Solubility is something like 2.4 grams per liter at room temperature - a bit less at warmer temperature. It does take some stirring to get it into solution but if the water is clear after adding it and stirring at the level of 4 grams per 6 gallons it should not precipitate out. I think that was chalk precipitating in your case - calcium from the gypsum and CaCl2 with carbonate from the bicarbonate.


Are bicarbonates only helpful if the grain bill is heavy on roasted malts and the pH would otherwise be too low?

Exactly right but some caramel malts pack a lot of acid too. If you do a brew heavy in them you might need some bicarb. Mash pH should be your guide.
 
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