Heatstick boils too hard -- solutions?

[wascostreet]

I built a 1500 watt 120v heatstick to help get my electric stove up to a more vigorous boil as well as make step mashing easier. I used it for my last batch and all was well until I really got into the boil stage. Problem was, with the heatstick in the kettle, the boil was too hard! It increased my boil-off rate about 20% but the real problem was that the boil was so vigorous that wort splattered all over the stove and countertop (3.5 gal boils in a 5.5 gal kettle).

Right now the heatstick is all-or-nothing -- just plug it in and let it go or unplug it to turn it off. Is there any way to vary the output so I can dial in a vigorous but non-splattery boil? I've read about solid-state-relays on these pages but the threads I found while searching were geared toward mash tun and sparge water heating, not adjusting the boil rate. I watch the kettle so I don't need a temp controller, just an output dial for the heatstick. I don't really understand how to do that safely.

PS -- one odd thing I noticed that I can't explain is that with the stove on high, my insulator wrap on the kettle and the heatstick off, my probe thermometer read 212 degrees at boil. But with the heatstick on, the probe dropped to 211 degrees but the boil was clearly more vigorous just based on the amount of steam coming off the wort. Any reason for that? Something about current induction in the boil playing with the probe sensor perhaps? I can't figure that one out.

 

[bad coffee]

PWM FTW.
https://www.homebrewtalk.com/f51/pwm-boil-kettle-control-159193/

 

[lackey2000]

I'm no expert but these three ideas came to mind:

Leave the stick on, turn down the stove?

Add a 120v switch to easily turn the stick off when biol gets too high?

Johnson a419 controller?

Good luck.

 

[wascostreet]

Ok, so I read through the PWM thread and lin and I'm not sure I need anything quite so high-powered since I'm only using 120V at this time. What about just using a kitchen range surface element controller? Those seem to be a sort of timer which would work, but what I really want is to reduce the output of the heat stick element. I still don't see that a PWM+SSR setup would do that -- thatt seems to be just a really fancypants timer for a big element.

Is there a guide anywhere in layman's terms I can look up? I'm pretty handy but I'm no electrical engineer.

...currently reading the wikipedia article...

 

[wascostreet]

Ok, so I think I understand a bit more here -- a PWM is used to tell an SSR when to switch on and off since a PWM is intended for modulating lower amperages (like activating a relay). So it is a timer in a way but the purpose is to vary the pulses only so much as they affect the overall output from the element -- short pulses create the effect of less heat generated since the element is only on for a lower overall percentage of that time. I gather that pulse timing for a heat element would be around 1-2 seconds for a medium output (roughly). As opposed to that, a stove surface element control varies the time in much longer pulses which would be less than ideal since I don't want the element approaching anywhere near full power during the boil. Am I getting closer to a real understanding here?

So my next point of ignorance is...what kind of PWM and SSR devices can I use for 1500 watts on 120VAC? And (please oh please) is there something off-the-shelf I can use? I assume there would be some wiring and a custom enclosure and I feel comfortable doing all of that provided I am on the right track to understanding how this all is supposed to work.

 

[RandomSF]

I boil with two 2000W 120V heat sticks. One is on 100% and the other is controlled by a kitchen range-top 'infinite switch'. The range-top switch turns the power on or off for several seconds, the amount of time depending on the setting. I maintain a strong boil in 7+ gallons without problem. It's the cheapest & easiest control I've found.

 

[sjlammer]

The easiest way would be to just leave the heat stick on full blast and turn down the stove burner... unless you are saying that the heat stick alone causes boil over.

The next easiest thing to do would be to buy an 8 gallon brew pot and do a full boil. this would likely lead to an increase in the quality of your beer, and you wouldn't have to buy a fancy controller/PWM. I'm not 100% sure, but i can't imagine a 1500 Watt heat stick would cause a boilover in 5.5 gallons.

 

[Cpt_Kirks]

Get a keggle...and another stick.

 

[BadgerBrewer]

Get a keggle...and another stick.

Will 2 sticks be enough to boil 13.5 gallons in a keggle? Or would I also need to keep some propane on it? What is the best wattage where it isn't too much?

 

[Cpt_Kirks]

I have boiled 13 gallons with them. Using two 2000 watt sticks, it took about 25 minutes to go from about 150*F to a jumping boil. Once I add some insulation to the keggle, the time to boil should be shortened.

 

[wascostreet]

Thanks for the responses. To clarify, I do half batches due to limited space and (so far) limited boil capacity, so my volume is a full boil. So sizing up isn't ideal since I'd have to size up fermenters, kegs and kettle as well. I intend to do so at some future time but not right now.

Also, the heatstick by itself is enough to cause splattering, so turning off the stove didn't work.

@RandomSF -- can you provide a little more detail about what infinite control you're using, where you got it, how you set it up, etc.? Thanks!!

 

[RandomSF]

@RandomSF -- can you provide a little more detail about what infinite control you're using, where you got it, how you set it up, etc.? Thanks!!

I got mine off eBay. Search for "infinite switch" and you'll get a number of them. Don't worry if they are for 220V, they will work just fine for 120V. They come with wiring diagrams. I put it in a small box from Home Depot. Mine nicely came with a knob, but HD or similar should have that, too.

 

[Jersh]

Ever thought of using a splatter guard? This one probably wouldn't work because of your heatstick being in the way, but I'm sure you could pick up a piece of screen at one of the box stores for dirt cheap and cut it to fit around your heat stick and secure it to the kettle with a few clamps. These are designed to keep pasta sauces and other thick simmering liquids from splattering all over the place while allow normal evaporation... Should help with your problem.

 

[HomeBrew-AZ]

Now once you are at a boil, why not just turn off the heatstick, remove it, and use your adjustable stovetop to control the boil? Can't you maintain a boil with the range?

 

[RandomSF]

Now once you are at a boil, why not just turn off the heatstick, remove it, and use your adjustable stovetop to control the boil? Can't you maintain a boil with the range?

Most ranges cannot maintain a boil on 5+ gallons of liquid. Lots of caveats apply, like open top pot, insulation, etc., but in general they don't put out enough heat for a typical 5+ gallon full boil that homebrewers do.