I made a Pale Ale in which I made a yeast slurry in a pint of warm (+/- 95 degrees F) water before pitching into the wort. Today I made a Porter in which I pitched dry yeast directly into the cooled wort and stirred it up. Could I have done both beers either way? How does making a yeast slurry differ from throwing the yeast on top of the wort and stirring it in?
i didn't say it wouldn't work if you don't rehydrate. rehydrating dry yeast is just good common sense. it prevents the dry dormant yeast from being shocked when it hits the sugar. brewing better beer is about improving your techniques and practices on the margins. if you rehydrate your dry yeast before pitching it will ferment healthier and faster.