News You Can Use
Keep a Cork in it: Stabilizing Sweet Wines for Bottling
If wine is not properly stabilized prior to bottling, microbes can grow and flocculate, as shown in this photo.
Residual sugar (RS) is an essential part of many wine styles, and in the northern varieties it can be especially useful. Depending on the titratable acidity and other characteristics, even “dry” wines may require a little RS to achieve a balanced mouthfeel. Sugar is food for people and microscopic organisms alike and in wine, unless steps are taken to ensure that the product is microbially stable, problems ranging from off-aromas to self-ejecting corks may appear.
Chris Gerling, extension associate in Cornell University’s extension enology lab, gave the Northern Grapes Project Webinar “Keep a Cork in it: Stabilizing Sweet Wines for Bottling,” in May of 2012, and discussed principles of filtration and other chemical & microbiological means of inhibiting or killing spoilage organisms, as well as the various costs and benefits.
Questions and Answers from the post-webinar survey – lots of good, detailed information here.
“Equipment for Small Wineries,” also by Chris Gerling, published in Vol. 3, Issue 2 of Northern Grapes News (p. 6-9). While much of the information in this article doesn’t directly pertain to wine stability, the article has a lot of good information about filters.
Chrislyn A. Particka, PhD
Extension Support Specialist
Department of Horticultural Sciences
630 W. North Street
Geneva, NY 14456