(NBBJ) - The tightest inventory of top varieties of wine available for purchase in bulk in a dozen years and a dwindling supply of those winegrapes could extend the rise in pricing for those fine-wine components into this year, but wineries are hard-pressed to pass those cost increases to consumers who are continuing to look for discounts, according to experts at a major local wine industry seminar this morning. The volume of wine California vintners were trying to sell to other vintners in bulk reached peaks of 15 million to 25 million gallons since 2000, according to presentations by Brian Clements and Marc Cuneo of Novato-based Turrentine Brokerage at the 21st annual Sonoma County Winegrape Commission Dollars & Sense seminar. Yet wineries’ aggressive efforts to reduce inventory since 2008 together with three lighter-than-normal harvests have siphoned the bulk-wine inventory down to 4 million gallons now.