I am a bit confused about Potassium Carbonate

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Oct 25, 2020
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Ok, so, I know what it does, why I need it, and I do need it (unless there is a better suggestion). I am making a melomel and I am trying with cherry for the first time which is very acidic and after 4 days the PH is now around 2. Long story short, I bought K Carbonate to combat the issue, except, the package says it needs to be refrigerated for a month after application. To my knowledge, the goal is to keep it at around 3.6+ during fermentation, and cold crashing will suspend the fermentation so that doesn't seem logical. Can I just toss in the required amount and let it keep doing its thing or am I supposed to wait til the end of fermentation? I cant find any serious info on what to actually do with potassium carbonate in mead, just a lot of people explaining how it works and why you should use it. I, and I think others, will appreciate the help. :)


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Jun 25, 2020
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I have the same question. There is a lot of discussion on this mead forum about adding Potassium Carbonate, Potassium Bicarbonate, or Calcium Carbonate. I understand that all of them are used to raise the pH, and that the first two also contribute potassium.

My question is why is this even necessary? I have been making fruit wines, and the pH goal for the must is usually around 3.4 to 3.6. Anything over 4.0 will make it much more susceptible to spoilage and will require far higher levels of free SO2 to prevent that. Most of the yeasts that I use are also happier in that pH range.

What is the target starting pH for mead? If the starting pH is in the 3.4 to 3.6 range, why would I want to raise that? The only time that I have needed to use Potassium Bicarbonate with fruit wine was with a cranberry wine that had a starting pH of 2.8.

I found some discussion of these issues in this thread: Potassium Carbonate


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Jun 21, 2014
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New Haven County
The only time I've used it is when following Bray Denard's BOMM recipe. In his thread on the BOMM he says:

Unfortunately, I do not have pH readings. Through extensive use, I've found that this small addition of potassium carbonate prevents the yeast from stalling out. Presumably by acting more as a buffering agent and potassium source rather than raising the pH.