For people who want to try making plasma from grapes in a microwave, here are the steps that work for me every time (I’ve done it for friends and highschoolers about 20 times)

1. Cut a large grape (1.5cm diameter) partially in half, leaving just a sliver of skin connecting the two halves.

2. Dry the cut sides by dabbing with a paper towel.

3. Place the grape halves cut side down on a Pyrex dish. Keep the turntable in the microwave (important, since microwaves have hotspots). Place the dish with the grape so that the grape orbits inside the microwave.

4. Microwave on high for 30s.

If you don’t hear a hum and see sparks within 10 seconds, you may have too large a grape. In that case you can try splitting the grape into two quarters, connected by a thin sliver of skin. Don’t forget to dry all the cut sides!