Aluminum vs Stainless

[AnOldUR]

No not that!

Just an observation after doing some experimenting with an electric burner.


I use a 60 qt stainless pot as on MLT and a 50 aluminum pot for the boil. With gas it's been faster getting the aluminum pot to a boil than the stainless. I was very disappointed when I could only get about 6 gallons to a good boil on an electric burner with the aluminum pot. Tried the stainless pot. Kept adding water a gallon at a time. It had no problem bringing it to a boil again each time. Got up to 12 gallons with a strong boil and decided to stop the experiment.

Both pots were wrapped equally with insulation and brought to a boil with the lid on and then taken off to hold the boil. The aluminum would get 8 or more to a boil, but as soon as the lid was removed the temperature would begin to drop below boiling (200 or so.) The stainless is fairly thin walled and the aluminum thick. Both are the same diameter (equal surface area.)

So, why the dramatic different results using a gas burner vs an electric burner?

 

[CidahMastah]

Was this boil going on outside?

I would assume that the heat conductance of the aluminum played against itself, if outside. It has been cold in NY, so same for NJ. Perhaps so much so that the aluminum pots superior heat conductance worked against it (cooling off too quickly). The stubborn stainless held onto the heat longer, thus, made for a better boiler.

If the boil was done inside, you have me stumped. The insulation thing sort of speaks against my theory though.... However, in theory your would need more insulation for the pot with higher heat conductance.

With the gas on the stainless - it takes longer to heat because the stainless doesn't conduct heat as well. Lots of the gas heat would be expelled to the sides as opposed to absorbed into the metal directly. Electric heat would provide for a more in contact/steady more absorb-able even transfer of heat into the stainless.

 

[AnOldUR]

It was done inside with both the gas and electric.

But I think you're on the right track. It seems like the heat goes right into the liquid with the electric heat and can get through the stainless faster rather than wasting energy heating up the thick aluminum.

Just guessing.

 

[Egbert]

Is the BTU capacity of the gas and electric heat sources the same?

 

[AnOldUR]

Don't know the BTU rating of either. The gas stove was at 18000, but I did some mods (opened up for more gas and air flow) so not sure anymore. The electric burner is around 4000W.

But I don't think it's a BTU issue. More the way the heat is being distributed. I just put a 10 gallon aluminum pot with a thinner wall on the electric burner with 9 gallons in it and it had no problem bringing it to a vigorous boil. Dumped that same water into the 12-1/2 gallon aluminum pot and it wouldn't do it. So now I'm thinking it may have more to do with wall thickness than material.

Anyone want to buy a 50qt aluminum pot with a stainless valve and thermometer? :cross: