As Mark and I are planning a visit to Champagne soon to look at bottling, disgorging and labelling equipment, I am still wondering what method and which equipment I will be using to “cold stabilise” the wines, to ensure that tartrate crystals do not appear. Remember, crystals in a sparkling wine usually mean that as you open the bottle you’ll lose half of it because it’s going to gush.
Previously we looked at electro-dialysis, which, in my opinion, is a proven, efficient method (colleagues around the world agree). The machine is quite simple to use, and as long as it is properly set up, it should function without problem. One downfall to this method, however, is that it requires a lot of water.
Nowadays, more than ever, wineries are dedicated to act responsibly and in a sustainable way. Sustainability involves water conservation. England might not be suffering from an enduring drought as California has lately, but water is still a resource that needs to be used sensibly. Electro-dialysis also requires energy in order to run (i.e. electricity).
More and more, producers are now using CMC (Carboxymethyl Cellulose) for cold stabilisation. It is cellulose gum, which is a natural compound originally found in wood’s cellulose.
If you are conscientious about what you ingest, you might have seen the food additive E466 somewhere on a label. That’s CMC, used as a thickener and emulsifier—possibly in other ways too.
CMC, after bench trials in the lab, gets added to the wine and modifies the structure of the crystals, inhibiting further crystallisation. Thus far, it has proven to be quite efficient, provided that proper testing of both the composition of the wine and the amount of CMC to add was adequately performed.
CMC may well prove an effective, cost efficient, alternative to electro-dialysis for the cold stabilisation of sparkling wine—I am eager to test this as soon as we can.
Jonathan Médard – Winemaker