Where does “brasa” come from?

brasa (Proto-West Germanic) comes from Proto-Germanic brasō, from Proto-Indo-European bʰres‑ — to burst; break; crack; crackle.

Ancestry of “brasa”, step by step

Step	Language	Word	Meaning
1	Proto-Germanic	brasō	gleed, crackling coal; fire, pyre
2	Proto-Indo-European	bʰres‑	to burst; break; crack; crackle

brasa — Etymology, Origin & Word History | Etymology Explorer