Make your own Calcium Hydroxide? Yeah, right...

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evoo4u

evoo4u

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In the interests of getting my mash pH up to where it should be without using lots of Sodium Bicarbonate, and not being able to source any Calcium Hydroxide, I followed the YouTube guidelines and made my own.

Pretty straightforward, and then searched around for a suitable dish to evaporate the moisture from the resulting goo. I know :super: - that big flat open Corningware dish we were given as a wedding present. Worked a treat. Several hours in a low oven, and I had a sort of baked-on powdery cake of Calcium Hydroxide, which I scraped off and crushed to a powder in the mortar & pestle thingo.

Then sat the dish in the sink with some soapy water to soak off the residue.

(Sometime later...)
Anyway --- I'm not the favourite home brewer in the house ATM, as it very nicely lifted all the glaze off the bottom and about a third the way up the sides of the dish. Not happy - we are not amused...

Don't know if the picture shows it too well, but there's got to be a lesson there somewhere!

Anyway, inspired now to conduct a more thorough search, I found a local (as in Oz) supplier of the ready-made food-grade stuff:
http://www.melbournefooddepot.com/buy/pickling-lime-calcium-hydroxide-food-grade-100g/PS0029

So it's on it's way, the chemistry lab has been dismantled, and I'll stick to making beer!

Corningware dish.jpg
 
I find that these dishes are good for making plastic explosive or nitroglycerine but wouldn't recommend for Calcium Hydroxide.
 
Not sure why you couldn't use chalk; you are trying to get the pH up so you're well below the pKa of carbonate.
 
Just noticed the reference to a 20kg bag of Hydrated Lime is gone. Perhaps as well - it might add a few unwanted trace elements to the brew...

Chalk? Very hard to dissolve I'm told, and if not in solution, won't do much to raise pH.
 
Chalk is soluble in anything with a low enough pH, hence the comment about the pKa.

The carbonate reacts with the acid, the CO2 produced exits the solution leaving calcium hydroxide behind.
 
evoo4u said:
Just noticed the reference to a 20kg bag of Hydrated Lime is gone. Perhaps as well - it might add a few unwanted trace elements to the brew...
Click to expand...
Just like using sea salt might add unwanted trace elements to your food. Hydrated lime is produced from limestone which in turn precipitated out of sea water.


hydrated_lime.png
 
FYI - CaOH and NaOH will both eat glass! They are a fairly extreme way to adjust water pH there are safer options (as above) Chalk works well.
You can buy 100g of food grade on eBay woolies click and collect CaOH
Mark
 
Wondering what your water report is and what you're brewing that would have you using excessive amounts of sodium bicarb to adjust mash pH??
 
timmi9191 said:
Wondering what your water report is and what you're brewing that would have you using excessive amounts of sodium bicarb to adjust mash pH??
Click to expand...
Rain water in a country area. Very soft, but have not had it analysed. I'm making the assumption it has no significant chemical bias in it.

I've had to add 4 to 5 grams Sodium Bicarb to raise the mash pH from 4.7 to 5.2, and unless I'm imagining it, the beers do seem to have a harshness. Now it may be other factors at play here, and maybe that amount of Sodium Bicarb is perfectly OK. But I wanted to try Ca(OH)2 to see if I could detect a (better) difference.

Overall, I'm trying to strike a balance between being anal and 'she'll be right mate'.
 
Yes it is pretty much insoluble (around 0.012g/l from memory), but acid ions in the water react with it reducing their population so the pH goes up.
Mark

missed your second post, I would be having a look at your pH meter and recalibrating it - be very unusual for tank water to be that acid.
M
 
evoo4u said:
I'm on a learning curve here. I understood that chalk really only dissolves in acid, and that would seem to be at odds with raising the pH?
Click to expand...
Another way of explaining this which may or may not help.

Your pH being too low means there is too much acid in the mash, adding the chalk to the mash will correct the excess acidity.
 
timmi9191 said:
What are you measuring pH with?
What size brews you doing? Light or dark beers?
Click to expand...
Hanna 98128, 22.5 litres (no chill cube style), both. Very happy with my porters and stouts, but a tad disappointed with lighter colours. This seems contradictory, as you'd expect the dark ones to be more acid, but I'm going by what the pH meter tells me. Maybe, the darker ones are more forgiving of higher sodium levels?

Mark, thanks for your explanation re chalk. I'll try some chalk next brew, and see how it goes.

Lyrebird_Cycles - good explanation. Thanks.
 
Lyrebird_Cycles said:
Just like using sea salt might add unwanted trace elements to your food. Hydrated lime is produced from limestone which in turn precipitated out of sea water.


hydrated_lime.png
Click to expand...
I'm aware that some agricultural/industrial products can contain impurities over and above what the label might suggest. ie - heavy metals in fertilisers, depending on the source, so I'm a bit wary of using other than "food grade" in stuff I'll be eating.
 
Bribie G said:
I find that these dishes are good for making plastic explosive or nitroglycerine but wouldn't recommend for Calcium Hydroxide.
Click to expand...
Have you looked at using metal its cheaper and no need to wash up.
 

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