Slight variation in color is not uncommon or indicative of a problem; the perceived color may change for the lighter for a variety of reasons. However, any sudden or significant change in color for the lighter is a problem. This spoilage phenomenon is rare and associated primarily with botrytis bunch rot, a vineyard disease. ProVina does not purchase grapes with any detectable bunch rot.
If your must suddenly changes and you detect the aroma of sauerkraut and/or salsa, this could mean that your wine is being degraded by enzymes associated with vineyard disease. Please contact ProVina by e-mail at email@example.com or phone at (877) 922-3122 for further assistance.