I’m having a problem perfecting my French Meringue Discs.  I’m using Rose’s recipe, but increasing the size to 15 oz egg whites and 14 oz each of the sugars to make 3 large discs.  The baking time is much longer than her recipe states:  my best effort so far was at 200 degrees for 4.5 hours.  But on most of the meringues that I’ve made, I’ve had some melted sugar seeping out of the discs.  Why would this be?  I’ve tried to incorporate the powdered sugar thoroughly, so that there are no lumps of sugar in the meringue before I bake it.  I live in the Pacific Northwest, so it is somewhat humid (80% humidity the last time I baked them).  Could that the the problem, or does anyone else have any other ideas?

I would say your high humidity is definitely a problem.

I made meringues last night and have the same problem you are having, so, looked up “How Baking Works” by Paula Figoni.  She says that the reason the sugar seeps out is due to undissolved sugar crystals which attract moisture and then create beads of syrup.  She advises using superfine or finer sugar (which, of course, Rose uses) and sifting to avoid any lumps.  It’s also quite humid here in Scotland just now so it might just be that we have similar weather conditions.  I actually made Swiss meringue where the sugar is dissolved in the egg whites before beating, so suspect that the humidity is the problem.