[nateo]

After reading Dr. England's mead presentation, where he talks about using potassium hydroxide to raise the pH during fermentation, it made me wonder why he didn't use calcium hydroxide. It's a lot easier to get a hold of than KOH. Does anyone know why he recommends KOH over CaOH?

[nateo]

I emailed Curt about this (pretty sure the Even-speed method was his). I don't think he'd mind me reposting the exchange:

Me: Mr. Stock,
I came across your Even-Speed-Mead technique on the AHA forum. I was
wondering if you had tested using calcium hydroxide instead of
potassium hydroxide. If so, was there some sort of negative flavor
from the calcium? What do you think the threshold for too much calcium
is?

Curt:
Calcium would help with pH adjustment, but as a vitamin for the yeast, potassium is better choice.  300ppm of potassium is ideal.

Not sure if there would be a flavor issue or not.  Good question though.

I have used calcium carbonate for pH adjustment.  Too much carbonate can affect the flavor and make an environment that accentuates harsher compounds.

When adding any thing to meads I like to keep the amount as low as possible.  Unless it's fruit or honey!

[positiverpr]

i was just thinking of the same question. i'm gonna make a mead this weekend and i'll titrate the lime per ph and try to post results down the road. i figure that this has been done before but i'm not finding anything on it. we should ask martin. hey martin?(said in fred flintstone voice calling for kazoo)

[thcipriani]

If you're looking for KOH check out essentials depot – they have food grade they'll ship you.

Be sure to add the KOH to water and not the other way around. You'll do 112.22g in 1L distilled water for a 2N solution.

I did it in a PP nalgene – you'll want something heat-safe it's an exothermal reaction. I think I remember reading you want to avoid storage in glass, too. Goggle and glove up!

[nateo]

In case anyone else wants to try using calcium hydroxide, I'd say use with caution. I ended up using a bit too much and the mead ended up seriously insipid/flat from low acidity. It had a pretty strong "mineral" fault. My wife said it tasted like a pepto bismol chew tab.

FWIW I ended up adding about 0.75g/L over the course of fermentation to keep the pH in the proper range. This is equivalent to adding about 400ppm of Ca.

[positiverpr]

i used some over the first week of fermentation of a mead 2 weeks ago and it did ok. after 2 days without any caoh the ph was 2.8 so i added 0.5g with my other nutrients. ph came up to 3.2. after 2 days the ph was back down to 3.1 so i added another 0.5g and had ph of 3.4-3.5 the next day. you gotta go very light on the lime. i pick up no mineral character.

[nateo]

I ordered some caustic potash so I'll try that on the next batch.

[nateo]

Be sure to add the KOH to water and not the other way around. You'll do 112.22g in 1L distilled water for a 2N solution.

I did it in a PP nalgene – you'll want something heat-safe it's an exothermal reaction. I think I remember reading you want to avoid storage in glass, too. Goggle and glove up!

Thanks for the heads up! I diluted it in a plastic pitcher. It got warm, but not nearly as hot as I expected. I added about half, stirred, then added the rest. I'm storing it in an old 2L soda bottle.

The stuff I got was in flake form. I'm sure it would've burned pretty badly if I had gotten it on my skin. I always wear gloves and goggles when handling acids and bases. But it was actually easier to handle than the lime, which is powdered and gets airborne really easily. 

[Brewdogz]

Nice thread guys.  Good information and experiences.

One thing about adjusting for pH - as the fermentation progresses the yeast will adapt to the lowering pH, to a point anyway.  Doing what positiverpr did is a good technique for keeping pH in the right range.

Thanks for sharing that info.

Curt

[nateo]

i used some over the first week of fermentation of a mead 2 weeks ago and it did ok. after 2 days without any caoh the ph was 2.8 so i added 0.5g with my other nutrients. ph came up to 3.2. after 2 days the ph was back down to 3.1 so i added another 0.5g and had ph of 3.4-3.5 the next day. you gotta go very light on the lime. i pick up no mineral character.

How big was your batch size?

[nateo]

So, in an effort to save my highly alkaline mead, I added the juice of 3 grapefruits. It's actually tasting pretty good now. The acidity is pretty balanced, and I think it'll turn out drinkable. The chalky-ness is not apparent anymore. It's still a little bit minerally, but you have to look for it.