3/4 of a cup is the recommended amount for 750mL of water (in a 1L flask)
Originally Posted by maskednegator
Not true. You can put it in at any time, but you should account for the change in gravity when planning your hop additions, as gravity affects the IBUs drawn from hops.
Maybe so, but unless you're hopping with something above 6%AA, it won't result in a significant enough IBU difference to be discernible. Saisons traditionally use low AA hops, so personally, I'd say it's pretty safe to add sugar at any time. If in doubt, 10-5 minutes is plenty of time, of course.