You’ve undoubtedly heard of Napa’s so-called “cult” wines—expensive, limited-production wines that are only sold to mailing-list customers, some of whom wait years for the chance to get off a waiting list and become buyers. These highly-allocated wines regularly garner three-digit scores from critics (always carry three-digit prices) and are considered trophies of a kind among certain wine circles.

But what if I told you that there was a class of Napa wines even rarer than these cult wines? Wines that represented the pinnacle of Napa winemaking—so unique that they sometimes are made once and never again?

These are the wines of Premiere Napa Valley.

Every year, in order to raise funds for the Napa Valley Vintners Association, a private auction takes place for the wine trade. Each auction lot is a single wine from an individual winery, made in quantities of anywhere from 60 to 240 bottles. In order to be included in the auction, these wines must be different and more special than what the winery normally produces.

Napa Valley producers take different approaches to crafting these auction lots, sometimes highlighting a grape variety they don’t often make, but most commonly making a unique blend or selecting their very best barrel from their top-tier wine to offer at the auction. In short, these wines often represent the apogee of a winery’s efforts in a given vintage.

For the past 15 years, I have been attending the Premiere Napa Valley auction, and it has become something of a personal sport for me to attempt to taste every single one of the auction lots. Regular readers will be familiar with my coverage of the event.

I like to say that some people run marathons for fun. I don’t like running. Instead, I taste the Premiere Napa Valley auction lots each year.

This annual tasting regimen gives me the opportunity to both get a clear sense of the vintage quality in Napa, as well as to taste the very best of what roughly 200 producers are capable of making that year. It’s hugely educational and lots of fun.

The people who bid on and buy these auction lots are a mix of retailers and private trade groups, as well as occasionally winemakers themselves. The retailers often make the wines they purchase available for sale to collectors, but quite often in ways that fly under the radar.

But the sub rosa status of these wines is changing. Both the retailers and Napa Valley Vintners are increasingly focused on making sure that consumers can get their hands on these wines if they want to.