How to on electric brewing, the basics

[azazel1024]

Our of curiousity for all of the electric brewers out there, I haven't found a whole lot, but what kind of heating times are you running with different sized elements?

My quickie poor back of the napkin math says that a 1500w element would take somewhere around an hour to heat 5 gallons of water from room temperature to a boil in a well insulated pot. Does that sound about right? So dual 1500w would be roughly half an hour and a 4800w element would be more like 15-20 minutes?

I have grandiose plans to eventually build a "real" electric brewery. That said, I am kind of curious if I could do a quickie PnP electric brewery with something like a couple of 1500w 120v elements or something similar Or do a hybrid propane/electric system where I use the propane to speed heating to mash/boil, but then use something like a single 1500w element to maintain the boil/assist with getting to temperature.

Anybody do something like that? Any thought's ideas? I pretty much just do 2.5-5.5G batches. I currently am doing BiaB, which I could see being an issue with an element in a pot, but I guess that could be avoided by not using the element for mash out heating. Any issues with elements and aluminum pots (price/weight I prefer aluminum, but curious about galvanic issues with a stainless steel element and an aluminum pot)? Would I need to go stainless pot if I went electric? Would a single 1500w element be sufficient to keep 5.5 gallons of wort at a boil if I brought it up to a boil using propane?

Could you insulate a pot and still use propane heating to assist the 1500w in keeping it at a boil?

Do you have to have a recirculating pump/whirlpool with direct electric heating to avoid scortching?

Just trying to get some ideas on how to save some propane and make the slow transition towards an electric brewery.

Thanks!

 

[Derp]

There are a couple of handy electric brewing calculators here:
http://www.brewheads.com/calc.php

 

[azazel1024]

Searching the forums is my friend. Doing as much looking around as I could, it looks like maybe building a 1500w heat stick at some point is my best bet for what I am thinking of wanting and needing. I could run it in tandem with my propane burner for heating mash water, then after mash out I could throw it in again to heat to a boil and for a lot of my batches it'll probably be enough heat to keep it at a nice boil. I am thinking a voltage controller would be good to go with it so I can adjust the boil.

My wife is going to hate me, but I can't help thinking of the savings*. I'd be shocked if I couldn't cut my propane use in half. In the winter when I am doing stove top, I'll probably also cut my heating and boiling times in half if used in tandem with my stove.

Shave time off my brewing AND saving money. Its almost miraculous.

*Probably not as much as I'd love, but I'd still bet I could save $20 a year in propane costs and cut my tank refills from twice a year to once a year.

 

[Owly055]

I brew 2.5 gallon batches and I use my stove top plus a 2500 watt element in a home made floating heater. The stove is gas, so I can't make a comparison that is meaningful, but I'm getting one degree every ten seconds

a gallon of water weighs about 8.4 pounds
one BTU is required to raise a pound of water 1 deg F
one BTU is .293 watt hours

The math is pretty simple

5 gallons of water is 42 pounds
If your water is 45 deg F, and you want to reach 212, that's 167 degrees
167 times 42 is 7014 BTUs
It takes 7014 BTUs to get the job done which is equal to 2055 watt hours in other words with no losses, a 2500 watt element would do it in 50 minutes.... in theory at least. In reality it probably will be a little over an hour.

Frankly, I'm not interested in waiting an hour plus for water to heat. I would want at least 5000 watts total power. It's worth keeping in mind that heat loss is a function of time and temperature differential, as well as thermal conductivity. You will lose twice as much heat over an hour as over half an hour.... It is efficient to heat fast. Insulation and covering your pot both help. Evaporation creates cooling. Anything you can do to control evaporation helps....... hence my floating element instead of a "heat stick". It covers about 60% of the surface area of my pot.

Don't be conservative.......... be radical. In this case it pays. My floating element runs on 240 volt..... It's well grounded, but how many folks have the never to drop a 240 volt heating element in a pot of water / wort....... It goes against every instinct we have about electricity. like throwing a toaster in the bathtub ;-)...... But it's perfectly safe....... Well grounded.
H.W.

 

[dlaramie08]

Math is math, but with my anecdotal experience, maintaining a boil on a 5.5 gallon into fermenter batch is too hard for only 1500W. I think it requires 3000W to maintain. I've tried to maintain with only one of my heatsticks running and it is a less than ideal boil with the vapor barely making a dent in the surface. That's with a layer if reflectix around my kettle sitting on plywood.

 

[Owly055]

Math is math, but with my anecdotal experience, maintaining a boil on a 5.5 gallon into fermenter batch is too hard for only 1500W. I think it requires 3000W to maintain. I've tried to maintain with only one of my heatsticks running and it is a less than ideal boil with the vapor barely making a dent in the surface. That's with a layer if reflectix around my kettle sitting on plywood.

As I said above, I would not be happy with less than 5000 watts if I were brewing 5 gallon brews..... reaching the boil and maintaining it are two different things. I would suggest a 3500 watt induction cooktop, and a 2500 watt heat stick or floating heater........ That's where I would go if I were electric brewing 5.5 gallon brews...... waiting is irritating. I want to brew, NOT wait.


H.W.

 

[dlaramie08]

I brew my batches with 3000W and it takes me almost exact same amount of time as when I brewed with propane with same size batches. There may be a total of 15-20 minutes extra over the course of a brew day compared to my setup and practices on propane. 3000W will get the job done just fine, but I am working on getting 240v so I can go up to 5500W to shave off those pesky extra minutes. Also, the money I've saved by switching to electric is/was worth the extra time.

 

[dlaramie08]

Sorry, OP, my point in all that rambling is that it can be done with 2 1500W heat sticks. I know, because I've done it. Spend a little bit on insulation and it makes a difference.

 

[azazel1024]

Thanks guys. I think I am really leaning towards making a 1500w heatstick or possibly a 2000w heatstick. Then also making some quick attach insulation for the pot. I am rarely doing batches over 4.5 gallons and my current largest pot is 6 gallons in size. A lot of my batches are in my smaller 5 gallon pot only boiling 3 gallons or so.

What I am hoping I can do is get a variable step down transformer for the element both so that I can precisely control the mash temp if I want to submerge it while mashing (seems like that might not be feasible because I do BiaB), plus no pump whirlpooling seems like a good way to scorch some of the mash. That said, it would be nice to be able to control the rate of boil off.

I am also hoping that I could implement that with a 2000w element and turn it down slightly for the times I am hooked up to a 15A circuit. Not sure how well that will work. I'll have to look in to it a little more, but I believe it would work okay. I'll just have to be careful with measuring power draw on the heat stick and mark 1500w on the dial. Probably not feasible to make a physical stop for 1500w (then again, I might be able to attach a screw on the dial and latch, so it'll stop at 1500w, move the latch out of the way to turn it up to 2000w).

I'd like to do that because in my kitchen the wall outlets are on a 20A circuit, but the outdoor outlet is only a 15A circuit (and also shared. I may need to install a 2nd outlet for the backdeck/seperate that outlet on to its own circuit. A pain, but not too hard, it is next to, but not attached to my garage where the main panel is). In my garage it is easy enough for me to run a dedicated 20A circuit. Or heck, easy enough for me to install 240V 30A dedicated. However, I generally only brew in my garage in the dead of winter when I don't want to do it in my kitchen or on rainy days when I "have to brew". I'd rather something flexible that I can use on pretty much any circuit.

Down the road I am hoping to get a 4 gallon pot as well as an 8 gallon pot for both my more typical 2.75G batches to keep down head space, better fit my wort chiller as well as the times I do my 5-5.5G batches (because BiaB), especially the really high gravity ones where I've got 16lbs of grain, plus a shed load of liquor in the pot. Maybe I can get away with not needing to double steep the grains between the 6 and 5G pots for my >3.5G batches, especially the higher gravity ones (I am not about to do a 5 Gallon RIS. Not planning a lift for the bag and I don't want to kill my back. 16lbs of grain in a batch of any volume is pretty much my limit, which means maybe a 4.5 gallons of RIS, or like 3.5G of Barley wine).

Anyway, I'll continue to use hot tap water to fill my pot(s) and then use a combo of the heat stick + propane burner to get to mash temp. Probably propane to rise to mash out temps. Then propane and heat stick to get to a boil and hopefully 1500-2000w will be enough to hold it at a boil, especially with a nice thermal wrap (probably make a thermal pad to sit the pot on too. Maybe cork pad cut to the size of the pot bottom). Fingers crossed that this will halve my propane use or a little more.

Right now it is taking about 15 minutes to hit mash temps if I use hot tap water on my convection top stove. About 15-20 minutes from mash out to a boil then. I am hoping the heat stick added to the stove top could cut that down closer to half the time. 15-20 minutes of overall savings wouldn't be a terrible thing. On top of that, the heat stick in the pot on my stove if it can keep it at a boil is probably also a little more efficient than heating it with my stove top (yes, eventually I do want an induction range, but expensive and not happening any time soon).

 

[TexasWine]

Do you have to have a recirculating pump/whirlpool with direct electric heating to avoid scortching?

Not sure this has been addressed, but if you're going to turn the element on during the mash the general consensus is that you should circulate. Some folks here on HBT don't, but I'd be concerned about burning a hole in my bag.

I'd also recommend buying a Hot Rod from BrewHardware.com as opposed to building a heat stick. You will not regret it.

 

[Firewalker11]

I'll bet that if you took a poll here about the tendency to move up in size and equipment type/quality, you would find an overwhelming majority that would say they would start with a larger pot, 240V and 5500W ripple element and not take the chance on an undersized, underpowered setup.

The pot material is a matter of choice, I have been cooking with aluminium for 30 years, once it has an oxide layer, it is impervious to just about anything and is fantastic for making beer.

Oh, did I mention it's cheap? 40 quart for $29 at STAPLES...

 

[pablosbrewing]

It takes quite a lot of heat to boil off water after it gets heated up to boiling temp. You also lose a heat to the surrounding air.

• To convert 1 pound of water to steam takes another 970 BTU
  
• So to boil off 1 pound of water per hour takes 284 watts + enough to overcome thermal losses.

 

[wbarber69]

I'm using ripple elements at 4500w and 5500w in 15.5g keggles. It takes about 15-20 minutes to get to a rolling boil from scratch. But after mashing you start heating while transferring and that can chop that down a bit. If you want to use elements but do not want to go the route of cutting holes and such go to brewhardware.com and check out the hotrod heat stick. You can use any size element you want so you can step up as you get your power needs met.

 

[wbarber69]

It takes quite a lot of heat to boil off water after it gets heated up to boiling temp. You also lose a heat to the surrounding air.

• To convert 1 pound of water to steam takes another 970 BTU
  
  
  
• So to boil off 1 pound of water per hour takes 284 watts + enough to overcome thermal losses.
  

1 pound of water is roughly 1/8th of a gallon. And by your math one could burn off a gallon per hour with a 2500w element. But in reality you'd be lucky to achieve 1/2 a gallon per hour with twice the element.

 

[azazel1024]

Thanks guys. I'll check out brewhardware.

As for what I can do, 120v is really my limit at the moment and I want it 1500w compatible. Roughly half my batches are only 3 gallon batches in a 5 gallon pot and I'll probably get a 4 gallon at some point. The other half are 4-5 gallons generally. I realize a rolling boil with only 1500w might be hard, but I plan to fab up some reflectivix insulation that I can velcro on to any size pot easily. Hopefully between that and sitting it on a cork pad should be sufficient to get a halfway decent boil on it. On my convection stove I am 99% certain that the largest "burner" is a 2400w element. That is more than capable set to 6-7 to keep my 6 gallon pot at a rolling boil with the lid half on when doing a 5 gallon batch with zero insulation and I assume less efficiency than direct heating would have. Having no idea what a setting of 6-7 out of 10 really is on the burner, I'd guess around 1300-1500w.

I don't need a lot of boil off ability. If I want that, I'll just turn on the propane. Enough for decent mixing, DMS off gassing, Isomerization, etc.

Why I am hoping I can do a hybrid 1500/2000w setup with a variable transformer so I can jump between my 15A and 20A circuits.

Long term I plan on a 240v "fixed" setup, but that is a few years away from having the dedicated brewing space.

I'll probably not use the element for mashing, just heating to mash in, heating to a boil (both of those using propane too) and keeping at a boil.

 

[wbarber69]

But why jump between 15 and 20amp. There is no reason to even have a 15amp breaker in your panel unless it's pulled from the panel to the receptacle with 14g wire. Which is highly unlikely unless your house is 80 years old.

 

[azazel1024]

But why jump between 15 and 20amp. There is no reason to even have a 15amp breaker in your panel unless it's pulled from the panel to the receptacle with 14g wire. Which is highly unlikely unless your house is 80 years old.

Errr, maybe I've looked at the wrong dozens of houses built from the late 1800's to to the late 2000s...but in almost all cases, a 15a circuit has 14awg wire. Which means you can't simply swap the breaker. Added in is that almost all 15a circuits I have seen also only have 15a outlets and switches.

Most houses from about 1960-1970 have undersized grounds on top of that (generally 1 step down, so 14awg has a 16awg ground, 12awg has a 14awg ground). Mine is in that range and it is all 12/14 or 14/16 wiring, with the exception of a bit of new wiring from newer electrical work.

Again, I've covered why I need to make the jump. I have some circuits that are 15a and some that are 20a where I might be brewing. I'd also like the flexibility if I ever went to a friend's house to do a brew and wanted to do it all electric (ex. I am thinking of my friend who lives in the city where his place doesn't have room for me to setup my propane burner, but I could certainly run a cord and do a small batch at his place).

I plan to probably do a 20a circuit in my garage, but since I do 100% of my brewing on my back deck when the weather is decent, there is no realistic way anytime soon to run a 20a circuit out there. It is feasible, but a giant pain in my butt.

Since I want to be able to control the output to moderate the boil (yes, I realize with only 1500w of heating power, on larger batches it is going to be hard enough to keep a good boil, but the times I do 3 gallon batches once I get a 4 gallon pot, with some pot insulation I'd imagine I WILL need to turn it down, even if it is only a little), why not go with a setup that can be turned up to 2000w for the times I have the circuit power and not just able to turn it down from 1500w?

 

[wbarber69]

What I'm saying is why waste all that time and money on a dynamic system and just use a 2200 watt element. You could use an extension cord with a gfi built in if you're in a situation where you can't get power to the location you need. While 14g wire can handle up to 20amps it isn't recommended. And in a 120v system the neutral line is basically the ground wire. So technically you'd have 1.5x as much travel to earth as you'd actually need. And instead of a switching regulated system all you'd need if you were worried about wire size would be to just swap elements. If you use a heat stick like brewhardware's it's like a 2 minutes process. Depending on what kind of control system you're looking into (pid on/off or voltage regulated) you aren't necessarily changing the wattage with your controls. Only the duty cycle of on/off. If you look into the way your hot water heater works you'll notice that most of them have 2 elements and the breaker and wire leading up to them is usually, depending on age of the house, only technically large enough to run 1 element. If you follow what the national code calls for.

 

[azazel1024]

What I'm saying is why waste all that time and money on a dynamic system and just use a 2200 watt element. You could use an extension cord with a gfi built in if you're in a situation where you can't get power to the location you need. While 14g wire can handle up to 20amps it isn't recommended. And in a 120v system the neutral line is basically the ground wire. So technically you'd have 1.5x as much travel to earth as you'd actually need. And instead of a switching regulated system all you'd need if you were worried about wire size would be to just swap elements. If you use a heat stick like brewhardware's it's like a 2 minutes process. Depending on what kind of control system you're looking into (pid on/off or voltage regulated) you aren't necessarily changing the wattage with your controls. Only the duty cycle of on/off. If you look into the way your hot water heater works you'll notice that most of them have 2 elements and the breaker and wire leading up to them is usually, depending on age of the house, only technically large enough to run 1 element. If you follow what the national code calls for.

It isn't a technically, I've only seen them large enough to handle a single element.

Which is all they do. They switch between the upper and lower element based on the thermostatic controls on them. The lower one (supposing they have the same temp setting) kicks on first as the water heater fills with inlet water and then eventually the upper element will kick on with the lower element turning off if enough of the hot water in the tank has been depleted.

I certainly wouldn't do PID, even though it would be fine with a 15a breaker, so long as the duty load was kept under the limit. Breakers are set to 125-150% thermal load and generally in the range of 200+% magentic load. This means that you can generally load the circuit from between 125-150% of its rated capacity for several minutes without issues. At roughly double the rated capacity it'll pop in large fractions of a second. This is so that the circuit can withstand short duration overloads, for motors. It also means transient overloads won't pop it.

So technically, even though you shouldn't, a 2000w PID controlled element could be used set at 90% duty cycle or lower, without tripping the breaker. It just isn't a good idea, as you are still technically overloading the circuit.

I'd go with a variable transformer so that I was actually driving the thing at a true 1500w.

Again, I want variable voltage control to control boil off rates anyway. So I might as well just use a 2000w element and it should be easy enough to use on a 15a circuit then. At 20a load, there is pretty significant losses in even a 12awg extension cord over the distance I am talking about (about 50 watts, roughly 1 watt a foot at 12awg and 18amp draw).

Also more costs. A nice 50ft 12AWG extension cord is going to run me around $40. A nice little 15ft 12AWG cord is going to be less than half of that.

 

[azazel1024]

Also, ummm, if something grounds out, it will ONLY travel down the ground wire and not the neutral wire. Your neutral better not be bonded to ground within the device. Only at your panel.

 

[wbarber69]

I'm just saying you'd be perfectly fine to run a 2000w element on what you've got now. Unless the wiring in your house looks sketchy, you're more than likely not going to trip anything. Of course you don't want to run your element on a circuit that already has a significant load on it. I'm just advising against all the extra stuff you probably don't need. Take it from someone who wayy overbuilt his own e-HERMS system because, just in case I need it later. I don't use half the features I built in. Except of course the mute all alarms switch.