Not all libraries lend out books, but even those that don\u2019t can deliver spine-tingling experiences that speak volumes about the classics. It\u2019s time to check out library wines.\r\n\r\nLibrary wines are portions of vintages held back by wineries to be re-released years after their debut. They\u2019re named as such because wineries refer to the section of their caves where they store their private stock\u2014usually a few cases from each vintage as libraries. Wineries are holding back more stock for this purpose and, increasingly, opening up their libraries to the public. How and why they do this, and how you can access a bottle or two, varies greatly by producer. Read on for a few examples.\r\n\r\nWhy Buy Library Wines?\r\nThere are several reasons why wine lovers seek library wines:\r\n\u2022The wines have generally reached peak maturity.\r\n\u2022Many collectors stock up on favorites they may have originally missed.\r\n\u2022Most wineries hold back slow-aging, large-format bottles (magnums and up), which are popular as wine-cellar trophies and gifts.\r\n\u2022People often seek vintages for milestone celebrations, and many wineries accommodate those requests.\r\n\u2022Library wines have been stored properly, and their authenticity is guaranteed. \u201cRestaurant owners don\u2019t go to auctions to buy older wines, but if they buy wines that have been aging at the winery, they know they have been well-kept,\u201d says Paolo Domeneghetti, founder of wine importer Domaine Select.\r\n\r\nLate Releases Versus Library Wines\r\nLibrary wine offerings are different from \u201clate releases,\u201d which is the term for when wineries hold back all inventory until the wine is aged and ready to drink, rather than selling futures. Some top Bordeaux producers like Ch\u00e2teau Latour do late releases. Doing so commands a higher premium on the wines.\r\n\r\nCh\u00e2teau Palmer is another Bordeaux producer that selects certain vintages for late release.\r\n\r\n\u201cWe late-release Palmer 10 years after the harvest,\u201d says Jean-Louis Carbonnier, the winery\u2019s director of the Americas. \u201cFor example, in September 2015, we offered 1,000 cases of Palmer 2005 to the n\u00e9gociants [Bordeaux wine merchants]. Selling price to their customers was 275 euros, when their en primeur [first release] selling price was 150 euros,\u201d says Carbonnier.\r\n\r\n\r\nHow to Find Library Wines\r\nRestaurants and wine shops are often the best conduits to find library wines. Tasting rooms and wine clubs are another avenue. Sometimes, however, there\u2019s a pecking order as to who gets the wines.\r\n\r\n\u201cWe offer these older wines first to our loyal wine-club members in December, then we offer the balance to our tasting-room guests during the winter and spring seasons,\u201d says Hagafen\u2019s Weir.\r\n\r\nSuch rewards are commonplace, especially among American wineries. But there are other methods to acquire library wines.\r\n\r\nMany producers sell older wines on their websites. Online wine merchants are also often offered allotments of library wines, which they\u2019ll offer to loyal customers. They can also contact distributors or wineries to find special bottles. Finally, for wine lovers who visit overseas wineries, older vintages are often available for reasonable prices.\r\nWhat the Wineries Say\r\nCh\u00e2teau Palmer, Bordeaux: Like many Bordeaux wineries, Ch\u00e2teau Palmer retains some inventory for later releases, called tranches. Palmer is unusual, however, because it retains half of its estate wine and about 1,000 cases of its earlier-aging Alter Ego for this purpose.\r\n\r\nSilver Oak, Napa Valley: David Duncan, whose father, Ray, founded the winery in 1972 with winemaker Justin Meyer, says it started its library program when it held back about 300 cases of the 1,400 cases produced in 1974. \u201cToday, we hold back between 1,200 and 2,000 cases, depending on the vintage, out of the around 100,000 cases we produce,\u201d he says.\r\n\r\nHagafen, Napa Valley: \u201cWe have a\u2026library program that re-releases our noteworthy red wines after 10 years of aging,\u201d says founder Ernie Weir.\r\n\r\nIt's not just the blockbuster producers offering library wines. Many smaller, funkier, more affordable wineries are holding back bottlings too. Don't be afraid to ask.