Five Gallon Plastic Electric Brewery
by Ken Schwartz, KennyEddy@aol.com
From Homebrew Digest #1990, 3/19/96
I've been receiving a lot of direct E-mail concerning people's questions
about the electric brewery approach, and I've been answering many of the same
questions over and over, so I think it's a good time to post a summary of my
brewery and give my two typing fingers a break. The inaugural "Pail Ale" is
still in the keg carbonating but preliminary sampling has shown it's just
fine -- no plastic taste or aroma; no signs of caramelization or scorching.
The information herein describes how I built my brewery and my design may
not apply to your needs or abilities. This posting is for informational
purposes only and does not constitute encouragement or direction for you to
build one. I make no claims about the safety or suitability of this brewery
design other than that I haven't yet been killed by it and that the beer I've
made with it came out well. Proceed at your own risk.
I used a five-gallon HDPE bucket for my HLT and a
seven-gallon HDPE bucket for my boiler. I made sure the buckets were at
least 0.090" (90 mils) thick by checking the thickness "rating" embossed on
the bucket bottom -- I found that the cheapo 0.070" buckets allowed the
element to sag when it got hot, but the 90 mil unit was just fine. For the
HLT I installed a single 240V/4500W "bent" water heater element (State
Industries #9000095) centered at 2" from the bucket bottom. I drilled a
1-1/4" hole using a hole saw. I placed the included gasket on the outside of
the bucket and secured the element inside using a 1" copper "female adapter"
fitting. A bit of teflon tape and maybe a nudge with vise-grips and I had a
secure leak-proof installation. The boiler was similarly constructed but
with two elements, one at 2" and the other at 4" from the bottom, mounted at
90 degrees to each other. For insulation I capped each element outside with
a 1" PVC pipe cap which has a notch cut in it to pass the wires. It attaches
with a few dabs of silicone adhesive for easy removal should I ever need to
remove the elements. Gives it a nicer "finished" look too. I marked the
outside of the buckets at gallon, half-gallon, and quart increments. You can
see the water level from the outside, and you can see the markings from the
inside, if the lighting is good.
I also installed in each vessel a 1/2" compression by 1/2" male pipe thread
fitting. I drilled a 5/8" diameter hole near the bottom, and inserted the
fitting compression-end first using a 5/8" "union washer" up against the hex
flange on the fitting, (on the outside of the bucket). The tight fit ( I had
to "cut threads" to install it) and the compression nut secure the fitting (I
discarded the compression sleeve). I silver-soldered a copper-wire "mesh"
(two wires in each direction) across the compression nut to act as a coarse
filter. Before installing, I connected a 1/2" female pipe inlet by 3/8"
compression outlet, CPVC "angle stop valve" to the fitting (for a tight fit)
using teflon tape. The 3/8" compression outlet on the valve allows me to
attach various lengths of water supply feed tubing to accomplish the various
liquid transfer functions. I suppose I could've used metal valves but the
plastic tolerates the heat, has low turning torque, and opens or closed in a
I run my brewery off 240V. The HLT is wired directly to
a plug and the element thus generates the full rated 4500W. Five gallons of
strike or sparge water heats from room temp in about 15 minutes or so. I
tried using a water-heater thermostat but there wasn't enough thermal
coupling to make this work well. I also found that the water underneath the
element stays cooler than the water above; there's not enough convection
without boiling to mix it up. So I have to stir it well before taking the
temperature to determine readiness for striking/sparging.
I wired the two boiler elements in *series* to give me 2250W total, 1125W for
each element. This ensures scorch-free operation. The 2250W level heats
sparged wort to a boil in 30-40 minutes, but the wort will boil over at this
setting. I use a diode (25A / 400 PIV) in series with the boiler wiring to
cut the power in half. The diode has a switch across it to allow full power
to be applied during heat-up; I drop it to half-power when boiling is
acheived by opening the switch. The diode is a bridge-rectifier module; I
couldn't find a single diode with sufficient rating. I got mine locally at a
pars-replacement house; part number ECG5324, about $6.
I strain-relieved the power cords to remove mechanical stress from the
element terminals. Otherwise, I would risk breaking the wires off at the
element from constant flexing, thereby creating a shock and/or fire hazard.
What I did was to bolt a cable clamp placed around the cord to the bucket.
I used a #10 brass bolt and nut with a "sealing washer" on the outside of
the bucket between the clamp and the bucket wall (it has a metal washer
bonded to the rubber; I placed the metal side against the cable clamp and
I built a two-tier stand (the floor is the third level) on
casters from 2x4's and plywood. I sized the stand so that liquid transfer
from one vessel to the next is all gravity; no siphoning. It doubles as
storage when not in use. All my control switches are in outlet boxes mounted
to the 2x4 frame, with switch and outlet covers enclosing them. I used a red
switch cover plate for my main power switch to make it readily visible.
Before I brewed beer I "brewed water" to check for
leaks and other potential problems, and to observe the process. This is
where I first noted the too-vigorous boil at 2250W and decided a half-power
setting would be necessary. Good thing, because 2250W DOES boil over. I
also accidentally fired up the HLT with no water in it. The element became
red hot and burned badly in *seconds!* I know now that it MUST be operated
only when fully covered with water!
I strike into my mash tun (single-step infusion; Coleman Drinking Water 5)
through metal supply tubing designed for the valve I chose. It take about
four minutes to strike 3-4 gallons but I am able to hit my target temperature
with great precision. I made sure I did a "practice run" first to determine
the temperature drop I was to expect. I decided not to just dump the HLT
into the mash tun because the buckets get hot and flexible, and I didn't want
to make a dangerous mess.
I sparge in a similar manner (using supply tubing), using the valve on the
mash tun (same kind) to slow the sparge rate to about 5 minutes per gallon.
The boiler is on the floor during this time; after sparging is complete, but
before I plug it in to boil, I lift the bucket to the mash tun level so I can
get at it easier, and, later, so that I can gravity-feed into the fermenter.
At 1125W I lose about 1/2 gal to evaporation per hour. When I "brewed
water", I lost 1 gal per hour at 2250W.
The CPVC supply tube from the boiler to the fermenter has three holes drilled
at a downhill angle near the spigot end, to act as an aerator for the chilled
wort. I got 5 gallons of wort with 1-1/2 gal foam on top in my 6-1/2 gal
carboy -- it just fit
I built an immersion chiller into the boiler bucket
lid. I used about 10 turns of 3/8" copper tubing wrapped around a paint can.
It hangs from the lid thanks to two elbow fittings installed on the top side
of the lid, which bring the tubing over the edge of the bucket. The cold
water enters at the top of the coil, which will hang just below the wort
surface, extending down to about the 2-gallon level. I place the chiller lid
on the bucket and into the wort, guarding the cooling wort from debris and
allowing me to gently "swing" the chiller through the wort for efficient
cooling. The chiller has a garden-hose fitting on the inlet side. I also
use a pre-chiller coil immersed in an ice bath after the wort drops to ~120F.
A small hole in the lid allows air to enter as the air in the bucket
contracts, and is also handy for inserting a long-probe thermometer for
monitoring cooling. I also stuck an aquarium thermometer on the outside for
an alternate way to read the temeprature (once close to pitching temp).
Plans for 120V Wiring
At some point I may make a 120V version which
might give me more flexibility in locating the brewery or even allow me to
bring it to a friend's house or whatever. It will use the same 240V/4500W
elements that I am already using. I'd need another element in the HLT;
otherwise it'll take too long for the water to heat (it's gonna take longer
as it is due to the reduced power). I'll wire the two elements in parallel,
but I'll need to play games with the diode approach since the two elements in
parallel will be very close to 20A and I'll probably get lots of nuisance
trips of the circuit breaker. If I wire a diode in series with one element,
I can limit the average current to around 15A (power = 1125W + 563W = 1688W),
while still obtaining reasonable heating times. Whether I would need to
switch down to 1125W by disconnecting the diode and element, to avoid
boilover, remains to be seen. I would be damn sure that the house-wiring
circuit I use is (1) GFI protected and (2) 20 amp rated (breaker *and* wire).
I'd estimate evaproation loss at 3 quarts per hour at 1688W (if it doesn't
Two things I noticed -- the hops colored the white boiler
green, and the acidity of the wort blackened the element wire. The black on
the element did not come off; I suspect it's an oxide layer and I'm not gonna
worry about it. The hop stain came out pretty well when I boiled plain water
for 15 minutes after hosing out the boiler real well (especially inside the
"female adapters"...no lewd puns intended).
That should give you a very detailed look at my brewery design. It allowed
me to get out of the kitchen (I brew in the garage now), to do full-volume
all-grain without hassling with a propane setup and the associated fire and
CO risks (although obviously there's a risk trade-off with the electricity),
to keep my batch size to a convenient five gallons, and to eliminate
siphoning from the wort production phase (I still use a glass carboy for
fermenting so siphoning is not totally gone).