I just tasted a wine that has much silkier tannins than I've ever tasted before. Is there a way to quantify the 'silkiness' of tannins in that wine vs another? Is it the average length of the tannin molecule? Would I need a gas chromatography mass spectrometer or some kind of fancy piece of equipment?
How can I measure tannins?
Measuring Tannins in wine is a complicated process and needs a lot of chemical analysis in a laboratory. It can be done, but not within reach of your average person. Here is a snippet from a pdf on the subject:
Wine total tannin: Tannins are a sub-class of phenolics that can precipitate proteins. They contribute to wine texture, particularly astringency. When grapes are crushed, the tannins present in grape skin and seeds begin to be extracted into the grape must. Those from skins tend to be more easily extracted than those from seeds. Once extracted, the grape tannins begin to chemically rearrange, turning into wine tannins, which can be significantly different in structure from the original grape tannins. Wine tannin concentration is reported in g/L in epicatechin equivalents.
A method to measure tannins in wine is called the MCP (methyl cellulose precipitable) tannin assay it is a simple and robust means of measuring the total grape or wine tannin in red grape homogenate extracts, red wine, and other aqueous solutions.
You can find the convoluted procedures here. It's really not as easy as they make it out to be.
Otherwise, it's a pretty subjective exercise. Each person perceives tannins differently. So, outside of a lab it's nearly impossible to quantify it.
