Yes, SOURDOUGHS is a Scrabble word!

Letter values in Scrabble US: S 1, O 1, U 1, R 1, D 2, O 1, U 1, G 2, H 4, S 1.

Is it a valid word?

SOURDOUGHS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a leaven of dough in which fermentation is active; used by pioneers for making bread
a settler or prospector (especially in western United States or northwest Canada and Alaska)