Power Control Resolution?

edited January 2021 in Usage


I'm finally kicking off my journey after spending nearly 8 years lurking whilst I life got in the way.

From all the reading I've done it's very clear that the energy input vs take off rate is critical for the quality of the distillate. The question I have is what resolution do I really need for the boiler. At present I'm planning to re-purpose my brewing boiler, which has 3 switchable elements (2kW, 1kW and 500W). I'm planning to cut into the wiring and use a SCR for power control, but I'm yet to decide if I put all three elements on controllers or if I can leave the smaller elements as-is for beer.

Could I control with on/off on 500w &1kW elements and a 2kW on variable? It will be feeding an Ace of Hearts

I could be fancy and just replace the existing controller with my own P&ID but I'd rather spend the time using the gear. I'm more likely to upgrade to a dedicated boiler down the track.


  • My opinion, every element on a controller. This way you will also prevent scorching with an element when on at 100% power. But, I would turf all (depending on a single large element surface area) and rather opt for a single controlled element if possible for your kettle size. My presumption is that your kettle is small.

    I am fortunate that we have designed our elements which result in a watt density of 6 W/cm2, this compared to Camco which are at about 18 W/cm2.

  • Not knowing what your electrical supply situation is makes the answer a little harder.

    Assuming you have enough power available to feed you 3.5 kW from one circuit, I would build a box with one SCR to control power to all three in parallel.

    Forget about PID (unless you’re planning to brew as well) as you don’t need temperature control. If you’re putting in a PID, make sure that you also have to option to switch to power control like some of the ones from Auber do.

  • The boiler is from my home brew gear, called a brewzilla. The elements are under the base like a cheap urn. Power isn’t a problem, I have 20A 240v. (Well 415V 63A from my welding outlet

  • edited January 2021

    Your three elements provide the following combinations in on/off.

    • 500W
    • 1000W
    • 1500W
    • 2000W
    • 2500W
    • 3000W
    • 3500W

    That’s fairly granular.

    Is variable SCR control better? Yes, however I’m not sure that’s possible with a Brewzilla - this is an all-in-one kind of mash setup.

  • edited January 2021

    It’s got a good amount of power steps, however I’m thinking power density for scorching. If the system is currently fed by one plug, it’s fairly easy and inexpensive to put a SD kit in front.

    Just looked up a brewzilla... not sure if the elements can be plugged in separately from the controller and I’d be worried messing it up with an scr in front of it

  • Yeah that's the first thing I thought of when I looked at what a Brewzilla was. You could probably rewire the whole thing, but that's some serious re-work.

  • Rewire is not a problem, I was half way through designing my own but the brewzilla was cheaper than the parts to build haha.

    I’ll prob run the SCR with basic PWM with a dial for distilling, and just run an ESP microcontroller as the brains. Then I can use it for the mash too.

    I’m getting excited, got sugar for the cleaning run and all the grain waiting for an AG bourbon. Want to run it!

  • pez
    edited February 2021

    Just to close this out I ended up using an ezyboil Auber controller and SCR. All three elements in parallel, but can be individually disabled with the original switches.

    Running my Ace I was getting good stable throughout down to 20% on power mode.

    Excuse the dodgy fan base, the printer died half way through and I haven’t fixed it yet.


    600 x 800 - 67K
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