why does celery spark in the microwave?

Answer 1

I am guessing carrot's logic also would work for celery:

If you often cook mixed vegetables from frozen in a microwave, on a microwaveable plate you may notice that carrots produce sparks during cooking and, on closer examination, they display small burns. Why is this? several factors make frozen carrots susceptible to the effect described (although other vegetables also do this).

Firstly, dense vegetables such as carrots have a higher amount of minerals in them - iron, magnesium and selenium - than other food items and sometimes create an arcing effect in a microwave. This tends to happen more in glass dishes. Sparks result as the microwaves reflect or bounce off the metal. the "arcing" does not harm the food, but it does prevent it from heating thoroughly because reflected microwaves will not cook. Also, extensive arcing can damage your oven's magnetron tube. If arcing occurs,turn off the microwave oven and finish cooking the food on the range top.
Arcing may occur in other vegetables, and most often appears in green peppers and green beans.

Secondly, while microwaves are extremely good at heating liquid water, ice is almost totally transparent to them, so it is actually quite difficult to get ice to melt in a domestic microwave oven. The "defrost" option on a microwave oven relies on intermittent heating of a small amount of liquid water present on the food, and heat conduction from these areas into frozen material. By putting frozen material into the microwave oven with continuous energy input, no time is given for thermal conductivity effects, and therefore a colossal heating effect occurs on a very localised surface area. These areas, typically at the extreme point of the carrot, will dry out rapidly and then char, essentially forming small carbon points.

Thirdly, carrots are relatively large objects (compared to, say frozen peas) and because microwaves are essentially varying high voltage fields, a large alternating electrical potential exists between the highly conductive charred sections.

Finally, carrots are generally given quite angular cuts, giving sharp points which will yield the highest field gradients. The combination of a large alternating field across a good electrical conductor with sharp points causes electrical breakdown of the air and the sparks which accompany this. Depending upon the precise conditions, it is equally possible for charring to be a secondary effect, rather than a cause. In this case, the discharge may originate from uncharred points, with charring only occurring as a huge current passes through a relatively small point.

Answer 2

It does? I have no idea but I am going to have to put celery in the microwave just to see it!

Chemical reaction I would assume?

Answer 3

I have never seen that happen and I have been using a microwave for over 30 years already.

Answer 4

why would u put celery in the microwave in the first place?

Answer 5

Never happened to me until today and I was reheating corn kernels cut from fresh. Corn that we boiled two days earlier. I saw a spark and a kernel caught fire and there was a burn mark on it after. The corn was on a plate and heated for only about 15 seconds.

Answer 6

Celery contains a high content of water. It is the water that makes it spark.

Answer 7

I would more agree with the cause being Mercury and heavy metal contamination in garden soils from imported vegetables, Food imported from unknown origins is always a poor choice for ones family.

Answer 8

I would think that perhaps it contains some metallic trace elements. I'm going to have to try this too. If this is true, then maybe cilantro will do the same thing. Cilantro is supposed to absorb metallic trace elements.

Answer 9

LOL....I've never tried to cook or warm up celery.

Answer 10

must have been grown in a metal soiled garden didt know that it sparks??? sure it wasnt wrapped in foil?