Otdfbt

A friend of mine cooks pasta in a modified electric water boiler which has been modified to keep going even after the water placed in it boils.

What are some advantages and disadvantages of this method over placing the boiled water in a pot and cooking it there over a gas stove?

Thanks.

Advantages:

• You can make pasta in your water boiler.

Disadvantages:

• Hard to clean.




• Waste of energy, a water boiler is on or off, it will
  expend full energy keeping the water boiling.




• Incredibly dangerous, a big fire hazard. Because it's modified to ignore the internal temperature sensor it will keep heating and
  heating even if all the water is vaporized. Once this is the case, it
  will start getting so hot it will melt the boiler and the metal of
  the heating element at which point your stovetop may catch fire.

Story about faulty kettle.

Advantages:

• you free up one burner in your stovetop, and one pot

Disadvantages:

• you might damage your equipment in the long term (starch might get in places where it shouldn't, and metallic parts will get damaged by the salt)


• you can't boil clean water in that boiler anymore (I doubt it will be easy to clean)


• if it doesn't have a temperature control, it will spill over - and you can't just "turn the heat down"

Others:

• you still need to keep an eye on it to check if it's cooked, as with any other method

It depends on the nature of your electric water boiler. I assume you are using a kettle-like device, but I may be wrong. If this is the case, then your pasta will be sitting atop and within the metal coils. You risk burning and deforming the pasta with this approach.

If you're in a bind and don't have access to a stove, I would recommend boiling water in the kettle, pouring it into a pot with the pasta, and replacing with the water with newly boiled water as it cools.

Even if you somehow took care of the safety issue that others have mentioned, for example by staying with it the entire time making sure there's always enough water in it, there's a practical issue that stems from this point (taken from Pieter's answer):

Waste of energy, a water boiler is on or off, it will expend full energy keeping the water boiling.

This is an important issue that's gotten overshadowed by the safety issue. While the energy waste is one thing, it's not just keeping the water boiling (like you would when boiling water on a stove) but it's on full throttle all the time meaning it will produce a lot of steam.

Let's say you start cooking your pasta when the water is already at boiling temperature and it needs to be going 10 more minutes. Assuming a water cooker with a power rating of 2000 watt (which is common in the EU) that means you're adding 2000*10*60=1,200,000 Joules to the boiling water. Taking into account the heat of vaporisation for water that means you're putting in enough energy to turn 1,200,000 /2257=532 grams of water into steam (assuming all the energy goes into heating the boiling water and no other heat losses).

When starting on this answer I'd expected it to be a bit more, but consider that half a litre is still significant if it coats stuff in your kitchen.

In the US this is probably less of a problem as the average water cooker there runs at 1500 watt or so.