Foam starts to appear once you profusely foment (stir up) a soapy hot water bucket(2nd meaning ).
Science students can easily remember it as it sounds similar to fermentation.. and stirring is an important part of fermentation process.
f[oment] => moment. In dynamic kinetics, moment incite wheel to rotate.
when a dog "foams at" the mouth it is "agitated"
foment rhymes with torment... when you torment someone, you stir anger up anger in the person.
sounds like ferment....when you ferment something you apply warmth to it(by keeping it in a cloth or closed vessel)
foment sounds like ferment
a batsman comes into form(sounds like foam) when he is INSPIRED by some one
STIRRING UP a soapy hot water bucket PROMOTES/INCITE the growth of FOAM.
stop stirring up eggs for a moment(foment) and add flour
sounds like tournments where players usually stir up and get instigated
extract the word "Foam" and think of the Foam used in fire extinguishers to put out a fire->Foment means to instigate,cause to burn,...