Sonic Introducing Slush-Flavored Hard Seltzers Add this to the list of something I didn't know I wanted until I saw it. Sonic has come out swinging in 2021 with what seems to be their very own line of hard seltzers. What most of us simply thought was a fad just a few years ago has become a billion dollar business. Brewers all over the nation have jumped on the seltzer train to try and get just a sip of the big money the low-carb beverages bring in. According to Food and Wine, the drive-in has taken their more famous slush recipes and brought them to an Oklahoma City-based brewery called COOP Ale Works. Greg Horton ( @winerev) helped begin spreading the word about the new beverages. He tweeted out the packaging that would be out in stores should this idea actually take off.