Heat stick brewing question

[Devinbrew]

Hi,

I'm attempting to brew in my apartment using a 26l kettle biab setup heated only by heat sticks.

My electric stovetop is really small and couldn't even fit the kettle so I voted for trying to rely solely on heat sticks.

I did a test run using water with a 2kw element and I have gotten only to around 205-208 Fahrenheit on 20 liters.

I was wondering about buying another element of 900W to push that last few degrees to boiling point. I also have an option to buy 1.4kw but I'm afraid whether that would lead to a too vigorous boil seeing I dont have that much headspace in the kettle.

Does anyone have any advice as to whether buying only the additional 900W stick would get me to boiling point?

 

[RPh_Guy]

I'm not an expert on this, but I have some thoughts:

2250-3900 ft elevation means your boiling point would be 205-208°F.

The actual wattage output of the element is limited by the current capacity (amperage) of your electrical circuit, so adding additional elements may not be helpful.

 

[Devinbrew]

The limited capacity of my electrical circuit might be the reason. I'm around 340 feet elevation I believe.

Would wrapping my kettle in insulation material help me reach a better boil and get a few extra degrees? I was also thinking of putting the kettle on top insulated material during the boil so that I'm not losing heat through the bottom either.

I'm a bit concerned that the boil rate at 208 might not be vigorous enough.

 

[RPh_Guy]

Check the amperage of your circuit. Not sure where you live but 15A 120V circuits are most common in houses in the US ... That could support up to only around a 1650W element.

Insulation would definitely help.

You definitely don't need a vigorous boil. Light simmer, or even hovering around boiling is fine.
You just get slightly lower hop utilization at lower temps.

 

[Vale71]

With that wattage and that amount of water you must be able to get the water to boil and somewhat vigorously too.
My guess would be that you purchased a heat stick that has some sort of built-in protection against boiling that will cut power as soon as the threshold temperature is reached. Check with the vendor if this is the case, if not then something else must be amiss.

 

[Devinbrew]

Thanks a lot for the advice.

I will check with the vendor whether the heat stick is cutting off but I believe it was heating continuously.

I checked my circuit and I'm on 25A 230V.

I suspect I might be losing too much heat due to the fact that my kettle is pretty wide (36cm diameter) and the heat stick also has a relatively small coil at the end which provides the heat.

I'm going to try wrapping the kettle in insulation material and see if that helps.

I was mainly concerned about not being able to boil off DMS at a good enough rate.

 

[mongoose33]

Do you have any way to cover the kettle? I know the heat stick cords get in the way, but perhaps using some aluminum foil or something would help. A covered kettle will always boil faster.

The insulation is a good idea. Don't know what you have access to for insulation, but I put my mash tun on some foamboard insulation to insulate the bottom, and I wrap it with reflectix insulation (not sure if either are available to you). I've also used reflectix on one of my boil kettles and it does help speed things up a bit.

 

[Vale71]

Thanks a lot for the advice.

I will check with the vendor whether the heat stick is cutting off but I believe it was heating continuously.

I checked my circuit and I'm on 25A 230V.

I suspect I might be losing too much heat due to the fact that my kettle is pretty wide (36cm diameter) and the heat stick also has a relatively small coil at the end which provides the heat.

I'm going to try wrapping the kettle in insulation material and see if that helps.

I was mainly concerned about not being able to boil off DMS at a good enough rate.

The stick will output 2000 Watts (or 2000 Joule per second) no matter what its size or shape might be. There is no way you cannot bring such a small volume of water with that much power to a decent boil. To lose that much heat you'd need to attach an actual radiator to the kettle.
Just to be clear, is there really no visible boil or are you just going by the (possibly unrealiable) thermometer reading?

 

[Devinbrew]

So I have bought some heat insulation material similar to reflectix and wrapped the kettle plus placed it underneath so that I dont lose heat there either.

I didn't talk to the vendor yet but decided to test it again with 20 liters of water. I'm using a thermometer and I saw that it got up to 200 Fahrenheit a lot quicker this time. After reaching that temperature the main body of water was around 204 degrees while near the heat stick slightly higher.

I don't think the power cuts off after reaching a certain temperature as the water right around the heat stick is bubbling. What I'm worried about is the rest of the water seems to not really boil, which does sound a bit silly.

Maybe I was just expecting something else? Never used a heat stick before. The heat stick is rather short though and the part that emits the actual heat is a spiral coil. So the heating surface might be a bit small.

Would I be able to get away with a boil like that if I'm planning to do all grain? I'm thinking I will still give it a shot the upcoming weekend and see whether boiling the actual wort might be a bit more vigorous.

 

[Devinbrew]

The stick will output 2000 Watts (or 2000 Joule per second) no matter what its size or shape might be. There is no way you cannot bring such a small volume of water with that much power to a decent boil. To lose that much heat you'd need to attach an actual radiator to the kettle.
Just to be clear, is there really no visible boil or are you just going by the (possibly unrealiable) thermometer reading?

I decided to go ahead and try to brew an all grain ipa using biab and this 2000w heatstick to see what happens.

I am watching a vigorous rolling boil right now! You were right it's more than enough, I think I didn't have the patience to wait it out because of the low temperature readings.

Cant wait to see how it turns out! Glad I was convinced from the replies here against buying an additional element.

Thanks again!

 

[doug293cz]

I'm not an expert on this, but I have some thoughts:

...

The actual wattage output of the element is limited by the current capacity (amperage) of your electrical circuit, so adding additional elements may not be helpful.

Check the amperage of your circuit. Not sure where you live but 15A 120V circuits are most common in houses in the US ... That could support up to only around a 1650W element.

...

The current draw and power output of the element are given by:

Watts = Volts^2 / Resistance and Resistance = Volts^2 / Watts
Current = Watts / Volts and Current = Volts / Resistance​

Thus an element rated at 2000W @ 120V will have a resistance of 120^2 / 2000 = 7.2 ohm, and if it is supplied with 120V, it will draw 120 / 7.2 = 16.7A. A 15A breaker in the circuit will not prevent the element from drawing the full 16.7A, since a breaker is a circuit interrupting device, not a current limiter, and the element will operate at full power until such time as the breaker trips. Whether a 15A breaker will actually trip at 16.7A, and how long it will take depends on the operating characteristics of the breaker. Breakers are designed to trip quickly at very large overloads, and much more slowly at small overloads. The smaller the overload, the longer it will take the breaker to trip. Also, due to trip level tolerances, it may never trip at 16.7A, in which case the element will operate at full power indefinitely.

​

Brew on

 

[RPh_Guy]

[quotes]

OP said he has a 25A circuit.

@Devinbrew Glad it worked!

 

[doug293cz]

OP said he has a 25A circuit.

@Devinbrew Glad it worked!

OP appears not to be in the US or Canada, so doesn't have to worry about 15A, 120V circuit limitations.

However, I was replying to the apparent misunderstanding you have about current limitations in structural wiring. A circuit breaker will not cause a heating element that draws too much current for the breaker to run at reduced current/power. If the current is too high, then the breaker trips, and there is no current. Breakers to not "throttle" current.

Brew on

 

[RPh_Guy]

Ah, thanks. When I saw it none of your text was there.

 

[doug293cz]

Ah, thanks. When I saw it none of your text was there.

Yeah, I accidentally hit the "Post Reply" button before I had actually typed my reply. Had to edit it in after