If I was making hard seltzer at scale, I’d consider two options:
-
Cut some Everclear 97% and some flavorant into water, and throw 30psi of CO2 on for it a few days (expensive)
-
Ferment some dextrose, rack it off the yeast cake, add some flavorant, and throw 30psi of CO2 on it for a few days (cheap)
My hombrew club hated me.
What you are doing probally does not sound as romantic as what they are doing. 🤣
The way they’re produced en masse is that high alcohol “beer” is brewed for maximum sugar content and minimal flavors, and then it’s aged, filtered, and in some cases concentrated for shipment.
Usually this neutral malt alcohol base is used on site at around 14% but if it is to be shipped it’s usually concentrated to liquor levels for economy of scale.
When it’s time to make a seltzer it’s not “brewed” as such, but simply blended with industrial scale batching equipment. Basically a big tank of water with a pipe loop that runs the contents of the tank in circulation, and has ports for adding flavoring and the alcohol base.
Once the batch is at the right flavor and ABV it can be held in storage or sent to canning/bottling, with compressed CO2 injected into the liquid line just before the point where it goes into the can or bottle.
