Since boiling wort is actusally at 215 to 220 degrees, 5 mins is probably enough. You try it first.
Next time, I'd just keep the wort boiling longer.
So far, I've had more experience thinking than I've had brewing....you don't think they are mutually exclusive, do you?
57 batches so far,
33 wine, mostly Loquat, peach, plum, prickly pear
22 beers and ciders
1 Tequila, from a prickly pear wine experiment that didn't work. I call it "Prickly Heat"