Ca(OH)2 Slaked Lime Calcium Hydroxide - Awful Flavor?

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Tonight I got water ready for a porter to be brewed tomorrow, and was taste testing my additions. I did only small amounts in a cup of water just to see how they worked. They were a little concentrated but not terribly so. Most dissolved in the water and weren't very noticeable.

When I got to the Slaked lime however, it was, well, nasty. And it wouldn't dissolve. Is this normal? I am skipping adding it this brew session until I figure out what the deal is with it. I know people add it, EZ Water has a spot for it, and I wasn't planning on much - 2 grams for a 5 gallon batch.

This is what I bought, should I actually go ahead and use it? https://www.amazon.com/gp/product/B074B8F2BP/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
 

Gnomebrewer

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It's difficult to dissolve in high pH water, and will quickly raise the pH as it dissolves, thus becoming progressively harder to dissolve. I'm sure some brewers use it, but I don't think it's very common (at the homebrew level). It's nasty stuff if you get it on your skin, and worse in your eyes.

It should dissolve more readily in wort, because wort is acidic, so maybe sprinkle it in at the same time as adding grain. Personally, I only use baking soda on the rare occasion some bicarbonate is needed. Unless your water is already high in Sodium, it's the easiest route to take.
 
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Thanks, I am leaning that way as well, use baking soda if needed. Having this slaked lime be able to dissolve in something more acidic makes a lot of sense now that you mention it.

Aside from the unappealing taste, the more I'm reading the less I want to have any accidents with it, as you pointed out. I'm reasonably cautious and know my way around a lab, but LOL instead of that making me feel safe it actually makes me more concerned because I know things can and do happen.

I'm realizing I need to learn more about additions and recommended pH targets , so it's not really such a bad thing to skip this. It would have been my first time using it anyhow.

Thanks again.
 

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Whereas Baking Soda raises water only to about pH 8.4, even the addition of very small quantities of Calcium Hydroxide will push water rapidly into the pH 11.5 -12 range. That degree of causticity would assuredly make it taste awful, as well as being potentially hazardous to taste it.

Via loosely extrapolating (OK, rapidly winging it) from some sparse data:
Solubility in water at 65 degrees C is likely going to be about 0.85 grams/L
Solubility in water at 25 degrees C is likely going to be about 1.60 grams/L

I was unaware of the solubility additionally being sensitive to the pH. Thanks for that info @Gnomebrewer!

The potential for highly insoluble Calcium Carbonate contamination seems highly likely with Ca(OH)2. And as CO2 dissolves into water with Ca(OH)2 in it the resultant reaction forms the same highly insoluble CaCO3. Even the humidity and CO2 in the air can turn nominally 'dry' Ca(OH)2 into CaCO3.

I'm going to speculate that much to most of your insolubility issue was due to the presence of calcium carbonate. The very small quantities of Ca(OH)2 used to raise the pH a tad in acidic beer should be flavor neutral.
 
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Thank you both for the replies. I had a gram of Ca(OH)2 in about a quart of water, attempting to dissolve it before I added it. I microwaved it briefly as well, 30 seconds or so, perhaps to 100 degrees, but it didn't dissolve. The pH part of that however makes a lot of sense.

Yeah... I tasted it, but just a small sip that I spat out. Won't be doing that again. I know better.

Sounds like it isn't a flawed substance but almost certainly a flawed way of gauging its flavor contribution.

Thanks again, it clears things up.
 

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Thank you both for the replies. I had a gram of Ca(OH)2 in about a quart of water, attempting to dissolve it before I added it. I microwaved it briefly as well, 30 seconds or so, perhaps to 100 degrees, but it didn't dissolve.
The solubility of Ca(OH)2 in DI water is officially listed at 0.66 g/L at 100 degrees C. That would be ~0.625 g/Qt. It's little wonder that you couldn't get 1 gram of it to dissolve in 1 quart of water after heating it. Sans for any extant (as well as likely) CaCO3 contamination, it should have dissolved relatively easily at room temperature, as Ca(OH)2's solubility is on the order of 1.51 g/Qt. at room temperature.
 

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2.96 grams of Ca(OH)2 adds 200 mg/L (ppm) of Alkalinity (as CaCO3) to 20 Liters of water. That would generally be be considered sufficient for mashing a Russian Imperial Stout.
 

Silver_Is_Money

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2.96 grams of Ca(OH)2 would also add 80.1 mg/L (ppm) of Calcium to 20 Liters of water.
 

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Would I be right to think that I can use Ca(OH)2 as one of the means of raising Calcium in my brew water. As mentioned above it is on the brewers friend as an option. I find that it is quite difficult to get near the Calcium targets for some beers with the Calcium carbonate ( chalk ) and gypsum ( CaSO4 ) as the chalk isn't very soluble and the Gypsum starts to skew the sulphate level.
 

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Would I be right to think that I can use Ca(OH)2 as one of the means of raising Calcium in my brew water. As mentioned above it is on the brewers friend as an option. I find that it is quite difficult to get near the Calcium targets for some beers with the Calcium carbonate ( chalk ) and gypsum ( CaSO4 ) as the chalk isn't very soluble and the Gypsum starts to skew the sulphate level.
Yes, but all things are best in moderation. Alkalinity will rapidly rise to become a problem, and some speculate that both the powerfully basic OH- ion and the very high pH that Ca(OH)2 induces can potentially do damage to malts. I hope that someone with more knowledge of the potential negatives will chime in to provide specifics here.
 

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Would I be right to think that I can use Ca(OH)2 as one of the means of raising Calcium in my brew water. As mentioned above it is on the brewers friend as an option. I find that it is quite difficult to get near the Calcium targets for some beers with the Calcium carbonate ( chalk ) and gypsum ( CaSO4 ) as the chalk isn't very soluble and the Gypsum starts to skew the sulphate level.
You also have to remember that if you add it for the purpose of adding Calcium, it will also raise pH. If the pH increase means you need to add acid, you might as well just add the resultant salt from the acid-base reaction. Eg if you add Phosphoric acid to counter the Calcium hydroxide, you're effectively only adding Calcium phosphate.
 

DuncB

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Thank you.

Actually my main hope for it was making a water profile close to a perrier water for the kegerator.

I used chalk to raise the calcium as per the website on the first couple of kegs.

.

and also the spreadsheet it links to


Trouble was I found the chalk used on my first workthrough never dissolved as I could still see it in the bottom of the keg when I next refilled.
Hence thinking that the Ca(OH)2 would be better from my calculation on brewers friend and on the spreadsheet.

My home water profile
Paremata water.JPG


and the brewers friend suggestion

perrier target.JPG


Open to another way of getting close to this though.
 
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