When I used a recipe for peanut brittle that worked in a higher altitude in a microwave it burned. Should I use less time or power? How do I know it is the temp. for a nice brittle?
Microwaving is not an ideal method for making caramel or brittle, as the heat generation from the waves is localized. It is too easy to get hot spots and burning while other parts of the mixture are under done.
Instead, you should use a more traditional stove top (hob) method.
I make peanut brittle in the microwave all the time and it comes out perfect.
I live at 2700 ft. my suggestion would be to cut down the cooking time and/or the cooking temperature.
I cook mine 2 minutes, stir; cook 2 more minutes stir, then a final 2 minutes. I don't cook it a straight 6 minutes to avoid hot spots and burning. hope this helps.