I bought an 1800 watt induction cooktop and 2 1000 watt bucket heaters that unfortunately were not able to boil 6.5 gallons of H2O in 90 minutes, although it appeared to get close and perhaps 0.5-1.0 gallons evaporated over the time.

I've read that brewers using induction cooktops sometimes add Reflextic or other insulation material to help the boil out, but in the pictures they all use lids.

Given that I'm using the bucket heaters, I can not seal the lid on.

Pardon the ignorance, but would insulation help the boil materially, if the lid was off?

Edit --

Well, I bought the Reflectix and adjusted it for my kettle:

enter image description here

It seemed to help the kettle heat up faster -- but the water never began to boil without me placing a lid on it, at which point it began to boil.

  • I've used 2100W induction with a blanket around the pot and got it to boil, but it still took a long time. You're 3800W should be plenty, unless: a. the pot is not thick enough/compatible with induction b. something is shutting of below boil temp (see homebrew.stackexchange.com/questions/13337/…)
    – Pepi
    Dec 12, 2014 at 9:03
  • Keep in mind that you don't want a lid when boiling - a long, vigorous & lidless boil gets the DMS out of your beer.
    – Pepi
    Dec 12, 2014 at 13:28
  • @Pepi did you use a lid until it started to boil? My kettle is induction compatible as I was able to boil a small quantity of water with the induction cooktop. My setup didn't boil after 1 hour and 45 minutes and then I decided to add a lid and it started boiling. After taking the lid off it kept boiling, but at a very, very small rate. Dec 13, 2014 at 4:52
  • I think I did. It was a while ago, and since then I used gas every time.
    – Pepi
    Dec 13, 2014 at 9:43
  • @Pepi I determined that the bucket heaters are turning themself off approximately at boiling temperature. If I turn off the bucket heaters, there is no observable effects on the boil (i.e., the boil doesn't decrease in intensity). I bought a third bucket heater, which should be a total of 4800 watts. Dec 15, 2014 at 22:27

1 Answer 1


Anything you can do to retain heat in a system improves performance so the answer is yes. That being said though heat does rise and a lid would have a much more dramatic impact on heat loss.

You can add a loose lid while trying to achieve boil. Once at boiling it takes less energy to maintain it than it did to get to the BP. So hopefully you have enough wattage to maintain a boil with the lid off after.

Just be sure to keep checking it so you don't get a surprise boil over when you aren't paying attention.

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