The fifth incarnation of one of Bottle Logic Brewing’s most sought-after beers is being sold this weekend, along with an extremely popular variant.

First up is Fundamental Observation 2019, a 13.55 percent ABV “liquid brownie batter” stout that has aged in a combination of barrels that previously held Buffalo Trace, Four Roses, Heaven Hill, Knob Creek and Woodford Reserve bourbon. According to the Anaheim, Calif.-based brewery, each individual barrel had multiple additions of Madagascar vanilla beans over the course of a year.

In addition, Bottle Logic will be selling Number Crunch 2019, an imperial stout brewed with vanilla and 300 pounds of Valrhona and Tanzania cacao nibs before being aged in bourbon barrels. According to a post on Bottle Logic’s Eventbrite page, this “ode to the chocolate bar” uses Fundamental Observation as its base, which is one of the reasons it is being released on the same day.

Both beers are members of Bottle Logic’s Stasis Project Series, which “celebrates the barrel as a fifth ingredient” and includes other notables such as Space Trace (13.6 percent ABV), Ground State (12.89 percent ABV) and The Lost Colony (12.5 percent ABV.)

According to Bottle Logic, the newest batches of Fundamental Observation and Number Crunch will be packaged in 500ml bottles ($23.95 and $24.95) and will have a six and three bottle per person purchase limit respectively. Interested parties will have the chance to order tickets redeemable for bottles on July 14 via Eventbrite and bottle pickups will start July 20 with no proxies allowed.