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Post by jerryla on Jun 10, 2007 13:19:17 GMT -5
Does any one know what is the desirable PH in fermented and dried beans and the PH in roasted beans.
I am trying to figth acidity in my chocolate and it seems to be good information to have.
Thanks
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Post by Sebastian on Jun 10, 2007 19:22:29 GMT -5
That's going to be a tough one for you to consistently measure, given the fat content of your beans is roughly 50% (pH is a measure of the - [H+] in water - so if roughly 65% of your component isn't water soluble (the fat + the insoluable fibers), it's going to be tough to get a meaningful, repeatable measurement). You could do an ether extraction i suppose and measure it in the resulting effluent.. or perhaps do a volatile acidity measurement under heat and capture/quantify the volitales, but you're gonna need some pretty sophisticated equipment to do that..
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Post by jerryla on Jun 11, 2007 10:32:55 GMT -5
Sebastian,
Thanks for your response.
The places where I buy my beans most of the times offer me a technical data sheet with PH numbers on it.
I just want to know what is the desirable range. I am not planning on getting this info myself.
Thanks
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Post by Sebastian on Jun 13, 2007 20:27:40 GMT -5
No idea - i've never bought beans on, nor even tested one for, pH...
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Post by sugaralchemy on Jun 19, 2007 1:00:37 GMT -5
I too have been curious, but there's no way I've been able to find to reliably and usefully test the pH of beans, and moreover, upon further evaluation, it doesn't really make much sense to do so. The issues are multi-pronged.
First you have the problems around most of the mass of the cacao being insoluble in water nor does cacao come in the form of an aqueous mixture. That doesn't bode well for easily measuring pH. Basically, without water, you don't have pH.
Second, the pH of the cacao isn't precisely correlated with taste. While lower pH tends to taste more 'sour' the correlation isn't exact. Different acids have different sourness characters, different properties when conched, roasted, etc. So the level of acidity is not as important as the type. Most common would be lactic or acetic, but the levels and ratios are determined largely from the fermentation process.
Third, the acidity isn't hugely relevant to the functional aspect of the chocolate. pH is critical to preserving many beverages. pH dramatically affects the functionality of hydrocolloids (food gums and thickeners.) pH is critical in products that rely on yeast and other microorganism activity. But none of those things apply to cacao as purchased for making chocolate.
So why would you measure pH or buy cacao based on pH? I'm not sure there are many highly useful reasons. Assuming a decent methodology is employed, it would roughly correlate with sourness, which might be nice if you were eating the cacao as purchased. But you will be roasting it, which will change some acids, and then further conching.
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Post by sugaralchemy on Jun 19, 2007 1:20:58 GMT -5
I guess I'm kind of replying backwards...
As for controlling pH. Try a longer roast. It can help bring down the acidity. Also consider a longer conch.
Commercially, alkalized chocolate sometimes is found. They neutralize all acidity with the use of a strong base, traditionally potassium carbonate or sodium carbonate.
In your own chocolate, a small amount of base added while refining can help control acidity. Because of the low water content, they don't act instantly but very slowly through refining. A small amount of baking soda will neutralize acidity, but don't overdo it or you'll develop off-tastes. Calcium carbonate isn't as potent and is much slower acting, but much more neutral tasting and a great source of calcium. There are many other possibilities. Anything dry, edible and with an alkaline pH is fair game.
Whether this is something you really want to bother to do, or whether it is really artisan, I can't say. But I can say that it does work, and it has even been used in commercial chocolates.
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Post by Alan on Jun 19, 2007 10:43:16 GMT -5
From what I understand based on my readings, 5.2-5.5 pH is the generally accepted "good" range for dried and fermented cacao. However, cacao such as Malaysian cacao, that has historically been too acidic, has ranged down to 4.7 pH.
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Post by sugaralchemy on Jun 19, 2007 11:09:33 GMT -5
Yes, so we have a 'good' range for pH. But then how do we trust the supplier to reliably measure it? This isn't like fruit juice, just insert a pH tester into the liquid and get clear, undeniable results. A clear methodology is required, and this methodology could be manipulated one way or another and is generally subject to error.
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Post by Alan on Jun 19, 2007 11:14:16 GMT -5
Yes, so we have a 'good' range for pH. But then how do we trust the supplier to reliably measure it? This isn't like fruit juice, just insert a pH tester into the liquid and get clear, undeniable results. A clear methodology is required, and this methodology could be manipulated one way or another and is generally subject to error. I agree. Better to go by flavor than by pH. Every cacao will be in "balance" with a slightly different tartness anyway, and that isn't even taking into account where the acid is coming from, i.e. volatile or non-volatile, (examples: acetic acid (volatile) and lactic acid(non-volatile)) and therefore to what extent it can be effected during roasting and conching.
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Post by seneca on Jul 5, 2007 18:57:14 GMT -5
Just agreeing with that as well...metrics are certainly important, but pH is one of the more problematic--talk to your friendly local winemaker about that. Better to focus on things like brix and ethanol, in my opinion.
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Post by seneca on Jul 5, 2007 18:58:44 GMT -5
Also, if acidity is getting in your way flavor-wise, I've had good success in conching at a slightly higher temp with a highly acidic batch of seed.
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