Have you ever found shards in your wine? My first experience with crystals aka “wine diamonds” (of course there’s a bougie name for them) came a few years ago, when I saw something unexpected at the bottom of my glass.
This was before I knew much of anything about enology, and as I fished the flecks out of the wine, I figured that I had chosen a bad bottle, or maybe some fault had occurred during production or storage to cause the strange see-through corn flakes to appear. Earlier this week, I found the little buggers (circled lovingly in red) in my not-so-cheap Gewürztraminer, and before running back to the merchant to complain, I decided to figure out what was what.
As it turns out, there is some debate about what crystals indicate in terms of quality— but there is no debate about what they are: KC4H5O6: potassium bitartrate. It’s basically cream of tartar, and cold temperatures (like those found in a refrigerator) cause potassium and tartaric acid (which both naturally occur in grapes) to link up and precipitate into these glass-like shards.
Totally harmless, natural, no problem to find them in your wine. The debate revolves around whether the steps some vintners take to eliminate the risk of crystals forming— namely cold stabilizing— has a deleterious effect on the wine itself. There’s another camp that insists that crystals only form in really nice wines, because a certain combination of components is required for them to exist at all.
Cold stabilizing is done solely to prevent crystals, and usually involves taking the wine down to near freezing (most people agree that below 40ºF is the standard) and then keeping it there for a few weeks. You’ll hear arguments that doing this can stunt, mute, or otherwise freak out the flavors and aromas in the wine. I’ll let you know what happens when my teeny batch of Chardonnay is done fermenting: I’ll cold-stabilize one bottle FOR SCIENCE!
Sigh. Real Genius (source of the above gif) is one of the few movies that just brings me right back to the unbridled optimism of growing up in the 80s. Potent nostalgia. Killer soundtrack too.
So, you can avoid crystals by not storing your wine in the fridge- storing it in a chiller is more gentle and keeps it closer to the ideal drinking temperature. If you do find diamonds in your vino, it’s probably best to decant the bottle and leave them behind: although they are harmless, they can have a bitter taste and a downright bizarre texture that ruins the experience.
I’ll be back with the bargain wine of the week tomorrow! Cheers, friends.