Ask Wine Wizard

Ring Around The Carboy


Sheril Wiseman — Sedro-Woolley, Washington asks,

I have made several batches of plum wine but this last batch has this yellow ring that has settled around the top of the wine in the carboy. It is ready to bottle but I don’t want anyone possibly getting sick. Have you heard of this and is there any way to fix it?

The short story — and the good news — is that no one will get sick from this batch because no human pathogen can survive in wine. Alcohol and acidity will kill off any bacteria or yeast that could survive in the human ecosystem and make you or your friends and family sick. For example, bacteria like E. coli, one of the most common bacteria implicated in food poisoning, need an environment where the pH is closer to that of the human body, around 7.0. Wine, with much lower pH (higher acid) of around 3.5 and with an alcohol content of 10% or more to boot, is a very hostile environment for the kinds of bacteria and viruses that can make people sick. This is why folks who drank more wine and less water (pH of 7.0) during the Middle Ages were not only doing something enjoyable, they were doing something smart for their health. “Rings around the carboy” happen frequently in winemaking, especially in fruit wines. I’ve had it happen to me at Bonny Doon Vineyard while making a
Response by Alison Crowe.