Any checking is probably done by audit and rather than by lab tests. This means they would check your recipe, purchasing records, brewing notes, and measurements to make sure they add up. There could be errors, but that's a lot of lies to pull off on purpose. I doubt the benefit would make it worthwhile.
- Sent by my R2 unit
Actually, they use lab testing to check ABV accuracy. And the TTB auditors know nothing
about brewing. And when I say nothing I mean NOTHING
. Both I have had to deal with have been retirement aged woman who had never worked in the brewing business before. Regardless, your recipe can add up but
if your efficiency is off thats a different story.
On the whole the TTB uses the ingredient lists and volumes of racked, BBT volume, shipped and dumped volumes to simply check to see if you are paying you taxes. As said before, they don't require recipe approval unless it is special ingredients - but you do have to report amount of malt, hops and sugar used per batch. The ABV thing is just a little something extra but they only fuss at you and make sure you show you are trying to fix it. If you aren't paying taxes though, then you are in trouble.