Makes a Sauce Thicker Through Boiling or Simmering

This page is the CodyCross answer for the clue below from Beach Bliss, Group 2051, Puzzle 4 (Beachcombing).

Question is: Makes a Sauce Thicker Through Boiling or Simmering

and the answer is: REDUCES

Word Meaning:

REDUCES — third-person singular simple present indicative of reduce

Definitions from Wiktionary.