Induction Cook Top: Boiling Water

[tomakat]

Ok, first of all, I'm not a cook. Second of all, this is the first time that I've used an induction cooktop. A couple of days ago I had a big stainless steel pot with about 1/2 full of water and I was expecting to be WOW'ed as to how fast the water would come to a boil. I first set the temp to 220F and I waited I think for almost 7 minutes and only a few bubbles were showing up at the bottom. I thought it was going to come to a boil in a couple of minutes. If I need to set the temp higher, what should it be? I was afraid if I turn the temp too high, I might damage my pot?

[LarrytheBear]

Just read where one person uses the "sear" option to boil water. (Outlaw Pilots blog)

[SarahW]

My induction burner "defaults" to 450 degrees when I turn it on, so when I want to boil water that's where I leave it. Your stainless steel pot should be able to handle 500 degrees without a problem.

[jrd48]

Is the pot certified for induction cooking? If a magnet won't stick to the bottom then it won't work.

[PushedAround]

Induction will heat the product inside the pot, not the pot itself, so don't worry about damaging the pot, you won't. The temperature options are for cooking and simmering. If you want to boil water, set it to high, or what ever the max setting is. Once the water starts to boil you can back it down. My unit will bring 2 quarts of water to a boil in about 3 minutes.

[LDMcL]

Originally Posted by PushedAround

Induction will heat the product inside the pot, not the pot itself,

PushedAround:

Sorry: Induction heating uses the magnetic properties of the pot to create heat which transfers to the pot's contents, cooking the food. Otherwise your hand will heat up if you passed it over the induction cooktop.

Its microwaves that cause the water molecules in food to vibrate, creating heat that cooks the food and the heat is transferred to the cooking container.

[PushedAround]

Originally Posted by LDMcL

PushedAround:

Sorry: Induction heating uses the magnetic properties of the pot to create heat which transfers to the pot's contents, cooking the food.

Thanks. That's basically what I meant to say in that the stove top does not get hot, but that the magnetic induction causes the pot to directly heat the product.

[Todd157k]

umm.. at the risk of sounding stuuuupid.. what altitude were you at? Water boils differently depending on the altitude.

[tomakat]

Originally Posted by Todd157k

umm.. at the risk of sounding stuuuupid.. what altitude were you at? Water boils differently depending on the altitude.

I could see the ocean from my campsite.

[tomakat]

Originally Posted by SarahW

My induction burner "defaults" to 450 degrees when I turn it on, so when I want to boil water that's where I leave it. Your stainless steel pot should be able to handle 500 degrees without a problem.

Next time I'll turn it up way high. I thought when I set it to the temp of boiling water 220F (at sea level), that it would reach that temp quickly through induction.

[docj]

Originally Posted by tomakat

Next time I'll turn it up way high. I thought when I set it to the temp of boiling water 220F (at sea level), that it would reach that temp quickly through induction.

Some induction burners, including ours, have both "power" and "temperature" settings. When I want to do something like boil water or heat a stew to cooking temperature I use the "power" settings so I can put as much power as I want into the food.

After it starts to simmer I can either turn down the power or switch to temperature control. Ours controls power down to 10% of maximum and I rarely switch to temperature mode.

But you do have to realize that induction isn't "magic". If you had several quarts of cold water in the pot you still have to provide just as much energy into the water to bring it to a boil as you would if you had it on the stove. That does take time.

In fact, if you had ~4 quarts (~4 L) of water at 10 degrees C and wanted to raise it to boiling (100 C) then you have to supply 4.184 joules (1 Cal) per gram of water x 90 degrees. 4 L of water is 4,000 grams.

Therefore, you roughly need to supply 1.5 million joules to bring the water to a boil. If your induction burner is rated at 1500 watts it can supply 1500 joules per second to the water (assuming 100% efficiency). That means it will take ~1000 seconds = 16 minutes to bring the water to a boil.

So seeing small bubbles after 7 minutes is just about right.

[cwsqbm]

Reading the instructions to my induction cook top, the temperature setting determines the wattage used. 220F would get 800W, while 425F is 1200W and Sear is 1300W.

I did a comparison test at home with a stop watch verse my gas stove and a measured amount of tap water, using the same pot. It was basically a tie.

[docj]

Originally Posted by cwsqbm

Reading the instructions to my induction cook top, the temperature setting determines the wattage used. 220F would get 800W, while 425F is 1200W and Sear is 1300W.

I did a comparison test at home with a stop watch verse my gas stove and a measured amount of tap water, using the same pot. It was basically a tie.

Our MH has a high-end residential propane cooktop with 9,500 BTU/hr = 2,800 W output. Assuming a 60% efficiency of burner heat to contents of pot that yields ~1650 watts.

So the heating capability of the burner is only slightly greater than our 1,500 W induction burner and a "tie" between the two is just what would be expected.

Induction burners have lots of advantages and don't heat up the kitchen as much as other cooking technologies. But they're not magic; physics is still physics.

[jrd48]

All you people do realize that the OP did say "stainless steel pot"? Stainless is non magnetic and won't work with induction cooktops without having a ferrous insert laminated to the bottom of the pot. That's why I asked if the pot was induction certified.