I just wanted to follow up a little more on this issue of using the acid test kit to test the acid levels in my mead.
As a reminder, from my last post the results of the acid test showed that my mead has 0.725% tartaric acid and 4.64ppt sulfuric acid. I calculated the TA (titratable acidity) to be 4.35g/L, based on instructions found online. According to some forums I’ve read online, measuring the titratable acidity using the acid test kit method may not be accurate for mead, since the sugars and other compounds in mead react a lot differently than those found in white and red grapes or fruit wines.
Here are some more details that I discovered about mead and how problematic it is to test the acid:
The issues are related to the unique chemistry of the honey used to create the mead. Instead of tartaric acid, gluconic acid is the dominant acid in mead. Where the issue lies is that in mead there is also a compound called gluconolactone that converts to gluconic acid as the pH level rises. If you think about it, when you’re running an acid titration on a mead, you’re adding a strong base (sodium hydroxide) to your acidic solution, thus increasing the pH of the sample. So, by adding the sodium hydroxide, the gluconolactone in the mead will actually convert to gluconic acid as the pH naturally rises during the process.
You basically end up having to add a lot of “extra” sodium hydroxide to the sample, since acid continued to be created during the process instead of measuring ONLY the acid that was in there prior to the start of titration. Too much base means that you are effectively overestimating the amount of acid in your mead.
If this is correct, that means the actual titratable acidity level in my mead is lower than 0.725%, but how much lower, I’m not sure. I foolishly did not taste the wine this time around, but it still had that “odd” smell it had previously. I’m thinking maybe the acid levels in my mead are actually too low? What I should really do is taste the wine again, maybe add a little acid blend, then taste again a few weeks later?
What do you all think? Am I on the right track thinking this way about using an acid test kit on a mead? Or am I totally off my rocker?
My name is Leigh Erwin, and I am a brand-spankin’ new home winemaker! E. C. Kraus has asked me to share with you my journey from a first-time dabbler to an accomplished home winemaker. From time to time I’ll be checking in with this blog and reporting my experience with you: the good, bad — and the ugly.