... So after all the article does not need to be present all the time.
Somehow in my head there is the believe that in some cases you have_to say the article. That believe must have started on Duolingo I think. If so -- what are the cases that require an article?
Sorry, my question is not well-formed and specific :-(
If you don't use the article you talk about the alcohol in general; if you use the article, you are usually talking about a specific amount of alcohol you are talking about.
I could make you an easier example if we use "vino" (wine). If I say "ieri abbiamo bevuto vino" I am generically saying that yesterday we drank wine (without saying what kind of wine) and that probably wine was the main beverage we had (we didn't drink beer, we drank wine). If I say "ieri abbiamo bevuto IL vino", I probably mean a specific bottle you are aware about (e.g. a good bottle of wine I already talked about, or the one you gave me last week).
It's mostly like the difference between the usage of definite and indefinite article.