I talked about five of my meads yesterday, and how I might decide if they were ready to bottle. I looked at clarity and specific gravity (SG) because I didn’t want the mead throwing off sediment or fermenting in the bottle. I tasted, probably the most important test of any wine or mead, and I checked the acidity.
Mead’s peculiar chemistry makes it difficult to measure the titratable acidity (TA). I explain this in more detail here, but the short version is that the common tests, like titration, overstate the TA. That made me think that such tests had no value, but I’ve since changed my mind. Measured TA’s don’t give you a precise value, but they do give you some information. That’s why I reported TA values for all five meads yesterday.
Using titratable acidity values in making mead
What do those values tell us? I began to get an idea about that when I was thinking about my cherry mead. As I said back then, you can use the TA values as upper limits. If you want to make a mead with the acid profile of a white wine, for example, you look up the range of acid values common in white wine then aim for the high end of the range. A good book on winemaking basics will give you that information. I like Daniel Pambianchi’s Techniques in Home Winemaking, he covers the basics really well and has special sections on ice wine, port, and sparkling wine. He says that the TA in white wines will normally range from 5 – 7.5 g/L. Adjusting a mead to 7.5 g/L puts the actual TA somewhere below that. Tasting the adjusted mead, after about a month or so to allow any acid additions to integrate with the mead, will reveal if the acidity is too low. If it is, then a series of add (no more than 0.5 g/L) – wait – taste cycles will nudge it right into the sweet spot.
Trying to improve a good approach
This is a good approach, but I’d like to get better information on the lower limit of a mead’s TA. Since the measurement error stems from the gluconolactone that exists in equilibrium with gluconic acid and that equilibrium depends on temperature and pH, maybe careful measurement of TA, pH, and temperature would yield some information on how much gluconolactone got caught up in the measurement. We might be able to use that to get a lower limit on, or even pin down, the actual TA. I don’t know how to do that yet, but I’ll see if I can find out. Another way to tackle this problem is to find out how much gluconolactone typically exists in honey. Putting limits on gluconolactone concentration will allow us to put limits on the actual TA. Those are my ideas anyway, if anyone can shed some light on them, or has another idea, please leave a comment and let us all know.
Did you ever make any progress with this? I’m really curious; I’ve looked at a ton of sites and am going to shoot for a 0.75% and see what I get.