Thanks Dr Tim! I guess I might try bleaching the blue ones (they're like $1.50 a pop) but I definitely won't try to autoclave them. I might try a couple of the black ones just for the hell of it. They're cheap - if they melt it's not a big deal.
2016: First year. Homemade evaporator out of little woodburning stove with steam tray pans. 6 taps on buckets. 1.1 galls syrup
2017: Same little homemade evaporator, but souped up. Still 2 steam tray pans. 15 taps on buckets. 4.5 galls syrup.