Hack Your Stove In The Name Of Homebrewing


[Tim] is a homebrewer. Temperature profiling during the mashing process is apparently even more critical than the temperature curve of a solder reflow oven. His stove just wasn’t giving him the level of control he needed, so [Tim] added a PID temperature controller to his stove. Electric stoves generally use an “infinite switch” to control their burners. Infinite switches are little more than a resistor and a bimetallic strip in a single package. Not very good for accurate temperature control. The tricky part of this hack was to make it reversible and to have little visual impact on the stove. A stove top with wires hanging out would not only be dangerous electrically, it would also create a hazardous situation between [Tim] and his wife.

[Tim’s] brewpot only fit on the stove’s largest burner, so that was the only one that needed PID control. To keep things simple, he kept the commercial PID controller outside the stove’s enclosure. Inside the stove, [Tim] added a solid state relay. The relay is mounted to a metal plate, which screws to the back of the stove. The relay control lines run to an audio jack on the left side of the stove. Everything can be bypassed with a switch hidden on the right side of the stove. In normal operation, the switch is in “bypass” mode, and the stove works as it always has. When mashing time comes along, [Tim] flips the switch and plugs the jack into his PID controller. The temperature sensor goes into the brewpot itself, so no stove modification was needed there.

The end result is a very clean install that both [Tim] and his wife can enjoy.  Save a few bottles for us, [Tim]!

10 thoughts on “Hack Your Stove In The Name Of Homebrewing

  1. I’ve hooked my PID box into whole bunch of things for controlling liquid temperature (in my case, for sous vide). My current setup, which btw would work quite well for mash, is a deep fryer with an external control box. The deep fryer is relatively small (you might have slightly more room in a 6 qt crockput, but not by much), but it does have a basket for easy removal of the food, was just $25, and, oh yeah, has 1300W of heating power. Bringing the water up to temp takes just a few minutes, and once the controller is tuned it literally just blinks the heater on every so often to hold temp. I really want to try this on an induction plate as it would be awesome to have an all-in-one temperature controlled portable stove with an external thermometer. Imagine how much easier sugar based stuff would be to cook….

    1. My golden ears and high developed palate beg to differ, good sir, and they do not take kindly to your insinuated slights.

      Ha, ha, yeah not really really.

      Brew one batch under ‘tightly controlled’ conditions (hey, put the lid that pot, dude) and pronounce it ‘amazing’.

      Brew a bunch under different conditions and blind taste them?

      Nah, too much work.

      1. Timing is more important than the exact temperature of the mash as long as it’s within the optimal range, because the chemical reactions that convert the starches to fermentable sugars proceed at certain rates and the final result will depend on the time spent at different temperatures, so having precise control over the temperature certainly helps in getting it right, but it’s not the be-all-end-all.

        In that sense, the old traditional method of pouring in well-measured amounts of boiling water to an insulated pot is superior to any electric stove because it’s instantaneous and precise.

      2. Been brewing for several years, more important than temperatures/times is sanitation, sanitation, sanitation. If it is an ale you are making, it is very forgiving when it comes to times/temps. If it is a lager, it becomes a little trickier. Those attempting lagers though are usually more experienced so a controllable mash-in temperature and cool down time are crucial.

    2. Maybe it does. Have you homebrewed?

      I haven’t, but at least I recognize that in order to discover whether a variable is significant or not, you often have to eliminate it. Which in turn may help you discover other variables.

      And even should [Tim] find that temperature control isn’t so important, as a bonus he’s all set up for some stovetop sous-vide. That I’ve done. And while I find some claims regarding it are exaggerated, it’s definitely worthwhile. The beef ribs I’ll be serving tomorrow, if you could sample them, would convince even you.

      I like the clean install. The hack itself is well done, regardless of the use.

  2. ^^ Time is only more important than temperature if you [i]need[/i] a full bodied beer otherwise the wort will be very fermentable (thus dry) but yeast strain along with fermentation temperature affects flavor and body and IMHO trumps both mash time and temp if you’re within a respectable range.

    I mash in a square chest cooler and lose about 1-2*F over the course of a 60- 75 minute mash and if I may be so pompous, I make consistently delicious beer and I usually hit my OG/ FG numbers on the dot. Never even tried sous vide or yogurt but this would probably be better suited for something you need prolonged, precise temperature control.

    That being said- anything in the name of better beer. This is a cool hack even if it is not the easiest mashing solution for Joe Homebrewer.

  3. Get one of those PIC “hot plates” like you see on TV.
    Better than hacking into your stove!
    They have two models, one is the simpler one, and the other is a bit better, more control etc… Still may want to hack into it to get better control. But no matter what, beats down the oven/stove.

  4. While controlling mash temperature is important. It’s biggest impact comes in brewing the same beer twice. You can brew wonderful and award winning beers in a well insulated container with no active temperature control. As long as you’re not swinging wildly or losing more than 3-4*F it’s going to be hard to discern any differences.

    Far more important is fermentation temperature control. That doesn’t by any means imply that active mash temperature control is a wasted effort. It’s not and I plan to implement it once I find a suitable stainless mashtun. All the big boys do it, and if you have the ability to so should you.

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