Just got the latest Avery Brewing newsletter (sign up here) an hour ago. Big news on the next Barrel-Aged Series beer:

“Sui Generis, which is #2 in our new Barrel-Aged Series, will debut at the Avery Tap Room on Wednesday, September 23rd from 3-8 PM. Due to extremely limited quantities of this brew (<150 cases will be produced), 12oz. single bottles will be sold only at the Avery Tap Room, between 3 PM and 8 PM on September 23rd. This free event will feature President/Brewmaster Adam Avery on hand in the barrel-aging room signing a limited number of bottles and answering questions on Sui Generis and other upcoming installments in the Barrel-Aged Series. Those who attend will have the opportunity to see firsthand the beers that will be coming next in our Barrel Aged Series. Since we have such limited quantities of this brew, it will not be on tap at the Release Party. Those attending will have the opportunity to purchase up to 6 bottles of Sui Generis and purchase pints or tasters of other Avery brews pouring from our 12 taps. Tasting Notes:
Sui Generis is a complex ale, aged and artfully blended from several types of oak barrels, and displays a delightful lactic sourness complimented by hints of brett, oak, and acetic. Intricate yet bold, deeply complex yet surprisingly refreshing, Sui Generis was crafted in the tradition of perennial Tap Room favorites De Vogelbekdieren and Voltron.

The first beer in the series was Avery Brabant which you might still be able to find at the store.