I applaud you for your patience in aging your bottled wines that long! Would you be surprised to know that in the US most bottles of wine are consumed within 72 hours of purchase? Well, perhaps they just don’t have the love and appreciation for a finely-aged wine that you do. I would also add it’s probably a little different when it’s your own. I always tend to curate my own library a little differently than something I pick up at the grocery store on the way home from work.
What you’re experiencing is the precipitation over time of all sorts of complex tannins and colored compounds. They came from the grape skins and seeds and have ended up in your nice bottles instead of at the bottom of a barrel where they should be. Sure, most red wines will throw some sediment over time. Red wines just have so many “guts” (tannins, anthocyanins, tartrate crystals) that naturally form larger molecules and will settle at the bottom of or against the sides of our containers.
So how to get away from having that thick coating on the inside of the bottle? Take it out before it gets in there. To follow are the top Wiz-approved ways to reduce post-bottling fall out (and the dismay that comes with it):
• Try using a fermentation enzyme during your red fermentations: By using a fermentation enzyme you’ll liberate a lot of colored compounds without having to do as much physical maceration. I find reds made with enzymes fall brighter and cleaner much faster.
• Make sure you’re racking enough: After pressing my skins and separating the liquid wine from the solids, I let the wine settle out for about 48 hours. Then I do my first rack off of the “peanut butter” (my technical term for the heaviest lees at the bottom), taking a small amount of the light fluffy lees with me into the vessel where I’ll do my malolactic fermentation. Then, after malolactic fermentation is done, I make sure to rack at least twice more during a wine’s lifetime before bottling in order to ensure proper settling. If you can see cloudiness in your wine before bottling, those little particles will eventually deposit themselves on your bottles during long-term aging.
• Age for longer in barrel before bottling: Is it possible you’re bottling too early? You want your wine to be brilliantly clear before you bottle it. I know that you aren’t filtering it, but you want to make sure you’re giving your wine enough time for the tiny particles to settle of course but also to allow a lot of the precipitate formation to happen and settle out before you rack and bottle. I like to see 18 months minimum for a barrel-aged red.
• Try protein fining of some kind: I know that you say you don’t fine or filter your wine but if this is a constant problem you’d like to fix I do recommend using casein, albumen, or some similar product. An easy “recipe” is to dissolve 1–3 egg whites (add a pinch of salt) in about 1⁄2 cup of water and gently stir into your barrel. In 2–3 weeks it should be settled enough to rack off. You would do this after any fermentation is complete. I like to do it around 9–10 months of age. By that time the wine has had enough time to settle out, get rid of its primary carbon dioxide gassiness, and has already dropped quite a bit of sediment.