If I’m cooking something in the microwave and punch in 30 seconds on the timer, then decide it’s not done and immediately do another 30 second run, is that the same as if I had originally cooked it for 60 seconds?
Timewise, it’s been microwaved for equal periods. But I’m wondering if there is something about microwave cooking that makes the 60 second run more effective (cooking more) than the two 30 second runs. Does the food lose momentum, in effect, during the couple seconds that it takes to reset the timer?
Depends on what you are cooking. If you are heating a frozen dinner, probably not; but starting and stopping popcorn will screw it up, resulting in more unpopped kernels.
For 30+30 with frozen food I’d say it’s essentially the same. But for food which can have some hard-to-unfreeze spots, sometimes letting it sit for longer or putting it on a lower power level will help the heat redistribute properly, so 2min + 2min > 4 min in those situations (30 + 30 would still essentially be the same since it isn’t even enough to unfreeze anything.)
Many frozen foods have instructions to heat in this manner. Often they will say to heat the item for (say) 4 minutes on 50% power. Your microwave does not have a 50% power setting (the unit that generates the microwaves is either fully on or fully off…no in between). Instead the microwave cycles on and off allowing your food to cook a bit from the heat already put in allowing for better heat distribution (if you’ve ever tried thawing meat in a microwave on full power you’ll see the edges cook while the center is still frozen).
That said heating for 30 seconds then immediatley setting it to go another 30 seconds is probably indistinguishable from just running it for 60 seconds.
Maybe yours doesn’t, but mine does. Most inexpensive microwave ovens do work as you say, however, there are ones which do have true partial power levels. These work by varying the power fed to the magnetron.
A 50% (medium) setting simply turns the microwave source on and off at timed intervals. You can hear the machine going through this heat, wait, heat, wait cycle. If you are cooking something that melts and bubbles, like cheese, you can see it cycling.