My first home brew ever is currently underway.
I am brewing a porter and pitched my yeast about 12 hours ago. Fermentation is very active already and that’s great!
BUT I’m concerned about some white dime sized clumps floating up top… are these normal or are they signs of contamination?
It’s most likely your yeast working away. I wouldn’t worry if it smells OK.
Without seeing it, it’s hard to tell, but yeast will sometimes look like white “clumps” floating before it foams up into a nice krausen.
Normally it should smell yeasty/bready/malty as it ferments. If it smells foul, you might have a problem, although some strains can smell a little funky normally.