Now that its shipment of crushed, dried-up insects has arrived, Bittermilk is nearly ready to start testing the fourth product in its popular line of mixers.

Bittermilk is using cochineal, the same natural coloring agent found in Peychaud's and Campari, to lend a red hue to its Sazerac salute. Although the mixer doesn't yet have an official name, co-owner Joe Raya says he and MariElena Raya plan to release bottles in time for the Charleston Wine + Food Festival in March.

The Rayas last fall launched Bittermilk from a small Charleston warehouse, with hopes of restoring dignity and quality to the just-add-spirit format. The first three releases - a smoked honey whiskey sour, a Tom Collins and a bourbon barrel-aged Old Fashioned - have performed phenomenally well. In December, the company sold 10,000 bottles.

"We had our 3-year-old putting stickers on tops of bottles," Raya says of the intensified assembly process.

Raya earlier this month drove back from Bardstown, Ky., with 31 bourbon barrels so Bittermilk can produce more Old Fashioneds.

Although the Rayas initially projected a cola-based mixer would take the title of Bittermilk No. 4, customer feedback inspired the classic cocktail tribute. To replicate the absinthe in a Sazerac, which originated in antebellum New Orleans, the Rayas are fine-tuning the mixer with fennel, star anise, licorice and wormwood, among other botanicals. The compound will be aged in rye barrels, since Sazerac is typically made with rye, although purists will sometimes substitute Cognac for some or all of the whiskey.

After a round of testing, the Sazerac will likely go into barrels as the month comes to a close.

"We're really excited about it, because it's paying tribute to the way these drinks used to be made," Raya says.