ArticleCork Variability, MLF Question, pH Testing, and Aceto ProblemsWritten by Alison CroweA concerned reader asks the Wizard why commercially-purchased wines might have their corks raised. She also answers questions on metabisulfite use before malolactic fermentation, when to re-test for pH, and dealing with Acetobacter issues.Already a member? Log InYou'll Also Like Article MEMBERS ONLY Fermentation Troubles, Natural Fining, and Get Your Swirl On Some home winemakers cool down must ferments by freezing gallon water jugs and tossing them (closed tightly) into fermenting totes, bins or trash cans of must during a punchdown. Article MEMBERS ONLY Alternative Sweeteners, Pomace Compost, and Stuck Fermentations If you add some kind of sweetener that is fermentable (table sugar, grape concentrate, maple syrup, honey, etc.) you risk an uncontrolled re-fermentation in the bottle, which is never fun.