The most common and most likely answer to this crossword clue is the 6 letter word STOUTS
I've seen this crossword clue in The Guardian
S
T
O
U
T
S
More clues leading to the result STOUTS
Buddy explains!

The straight part
We know that "Drinks in barrels" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case drinks in barrels = stouts.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does STOUTS mean?
STOUTS noun- A dark and strong malt brew made with toasted grain.
- An obese person.
- A large clothing size.
- Gnat.
- Gadfly.