foam up

verb3

1. •
   To become foamy, create a foam; to rise with a foamy surface or covered with something resembling foam

   • When the first rain hits […] that big pipe carries a lot of water that blasts the algae and sediment, which then foams up. — 2010
2. •
   To cause to become foamy; to cover with foam.

   • As I routinely foamed up his grand lattes, he’d share details about his homicide cases (not to mention his rocky marriage, which was still bordering on divorce). — 2006
3. •
   (figurative) To take place, arise, erupt, develop.

   • A tide of Republican scandal foamed up last week and engulfed Germany's greatest post-War soldier, Hans von Seeckt, “The Man with the Iron Monocle.” — 1926