boil down

As an allusion to the technique of reduction or decreasing liquid content of food by boiling much of its water off.

boil down

1. (transitive and intransitive) Used other than with a figurative or idiomatic meaning: see boil,‎ down.

   He boiled the soup down so it wouldn't be so weak.

2. (intransitive) To become reduced (to the most central elements or ingredients: to the essence, core, or implication for action).

   So what this boils down to is that you still owe me that fifty bucks.

   • 2013, Daniel Taylor, Andros Townsend calms England's nerves in taming of Montenegro (in The Guardian, 11 October 2013)

     For England, everything now boils down to what happens against Poland on Tuesday.

3. (transitive) To reduce (to the most central elements or ingredients: to the essence, core, or implication for action).

   My dissertation is 342 pages long, and I'm required to boil it down to a one-page abstract?!

• Usually followed by to, as in some of the examples above.
• What usually get boiled down are problems, arguments, statements, etc.

• (become reduced): come down to