Electric Burners

[SeanD]

I have an electric two-burner hot plate that will fit beautifully under a steam pan I can use as a finisher. It also means I can finish in the sugarhouse which would be nice. It's the flat coil type like a stove top.

Is that type of heat okay or will the electric burners scorch the syrup on the bottom?

Sean

[RileySugarbush]

Sean, It probably won't really scorch it but what will happen is it will boil locally at the points where the pan touches the coils. If you can hear that little hiss, that is boiling even if you don't see bubbles. Boiling means niter.

So, as a finisher it is OK since you will be filtering again. As a bottler, not as good unless you are using it to hold temperature of already hot syrup. For that, a water jacket works better, or even a gas burner since the heat is better distributed.

[Kev]

what if you put a heavy alluminum plate over the coils(the same size as the bottom of the pan) and then the canner on top of that. would that spread the heat out more and reduce niter ?

[SeanD]

Thanks, John. I think I'll just use it to finish in the SH and continue to bottle in the house.

I think the plate idea is a good thought, but I don't think this little rig can put out enough BTUs to get heat through another surface and into the pan.

Sean

[PerryW]

Also, electricity is an expensive way to make steam. You could buy a gallon of syrup for less than the electricity required to evaporate 39 gallons of water.

[RileySugarbush]

what if you put a heavy alluminum plate over the coils(the same size as the bottom of the pan) and then the canner on top of that. would that spread the heat out more and reduce niter ?

That would help avoid the hot spots but add a lot of resistance to heat flow. It might not transfer heat well at all. Every contact surface in the heat path adds insulation. In that case: Heating element, electrical insulation in coil, coil surface to plate, plate to pan.


That is a lot of steps.

If you look at a good stainless frying pan or pot you will see that there is a thick aluminum plate boded to the bottom. That is the same as your idea but without the additional contact surface since it is in intimate contact with the stainless.

[Kev]

That would help avoid the hot spots but add a lot of resistance to heat flow. It might not transfer heat well at all. Every contact surface in the heat path adds insulation. In that case: Heating element, electrical insulation in coil, coil surface to plate, plate to pan.


That is a lot of steps.

If you look at a good stainless frying pan or pot you will see that there is a thick aluminum plate boded to the bottom. That is the same as your idea but without the additional contact surface since it is in intimate contact with the stainless.

Stainless has a heat transfer coefficiency of 16.0 Aluminum has a coefficiency of 221~250. (depending on the temp it is tested at)
the higher the number the better it works at transfering heat.
the aluminum will pull heat from the burner and transfer it to the stainless better(and more uniformly) than the stainless pulls heat from the burner.
that is the point of the aluminum in your example
that poor tranfer rate of stainless is why the stainless pan you boil syrup in is not all that hot at the top of the sides compared to a few inches above the arch. only a part of the reason is the sap pulling heat out of the pan

[Kev]

that is not to say the better the contact between the stainless and the aluminum the more effective the transfer. you are 100 percent right in that

[RileySugarbush]

Adding something that is pretty good in series with two bad things doesn't help the total. The key here is that it is in series.

Stupid analogy alert:

The aluminum plate is like adding a short 2 foot diameter culvert between two 50 foot long garden hoses and expecting more flow. the culvert doesn't make matters much worse, but it certainly doesn't help. The flow still needs to go through the two hoses. ( not a perfect analogy of course )

End analogy.

Your aluminum plate spreads the concentrated heat out over a wide area at a lower temperature and that is good for reducing local hot spots. Unless it was bonded to the stainless pan, it is likely the overall heat transfer will go down a bit. If it did go up some, (and that is possible since a larger area is hot, but not as hot as the coil), I think it would be a very small amount.

[CBOYER]

I have used some years ago a small 4 rounds range in my garage (low cost electricity in Qc), whit aluminium pans to boil, but i finish last 2-3 degres in home kitchen on propane burner, under hood.
On electric spiral elements you could see in pots where it touchs. very hazardous to finish on it, could burn easily.