Ask Wine Wizard

Dealing With Persistant Sediment

TroubleShooting

Wil Malski — Grand Haven, Michigan asks,
Q

I’ve been growing my own grapes for 5 years but have been making wines for over 10 years. I’ve made some really good reds over the years but no matter what I do I always end up with some sediment in the bottles. I’ve tried fining with egg whites, bentonite, and isinglass. I’ve tried fine filtering with my Buon Vino Super Jet. And I always do 7+ rackings over the course of 14 months. I wait at least a couple months after the last racking to make sure there’s no sediment on the bottom of the carboy before bottling. But no matter how clean the wine in the carboy was some sediment always precipitates after I bottle it. It doesn’t impact the flavor and is only noticeable when the last glass is poured but I don’t feel proud giving it to friends. What do I need to do to prevent this from happening?

A
AGoodness, you’ve got a persistent sediment source in your wines that’s for sure. You’ve removed the gross particles by racking and filtration.You’ve cleared out proteins by using bentonite. You’ve taken out excess tannins with proteins like egg whites and isinglass. Also you’ve provided plenty of time for settling before bottling and have sterile-filtered right before bottling, excluding any spoilage microbes which might start some kind of post-bottling fermentation and sedimentation. What this tells me is that the source of your sediment(s) is/are smaller than the 0.45-micron size of a bacteria cell, and that it’s something happening on the molecular level in your wine. Let me run through some things that might help, depending on what is causing your post-bottling instability: -Don’t make any last-minute blends: I’m guessing your sediment is coming from unstable color compounds, potassium bitartrate crystals, or a mix of the two. Both are small enough to pass through a sterile filter and affect your wine down the road. Are you making blends right before bottling? Even if you have two different batches of racked, fined, and filtered
Response by Alison Crowe.