Intro: Recirculating Gravy Fountain
thanksgiving 2k5 : what's more excessive than a giant pie? recirculating fountains of food seemed like the obvious escalation. a custom peristaltic pump design powered by an electric drill provided a gushing torrent of delicious, piping hot gravy.
Step 1: Pump Design
the key component of a gravy fountain is a gravy pump. while there are a wide variety of commonly available
pumps based on impellers, these would at best cut up the giblets or even jam on thick gravy. instead we
based our design on the peristaltic pump, used, for example, to move blood without damaging the blood
cells (blood cells being analogous to giblets and blood being analogous to gravy).
six plastic rollers arrayed in a hexagon (nature's polygon) roll against a large diameter flexible hose.
pockets of gravy trapped between two successive rollers are gently transported around the circumference
and squirted out the top.
the sheet metal backing plate (leftovers from the previous thanksgiving) was left intentionally springy to
assure a good seal without precise tolerances. the tubing was glued to the backing plate with construction
adhesive providing a strong but flexible bond.
to power the pump, we used a cheap electric drill from harbor freight. this is an incredibly easy way
to add a variable speed, high torque motor to any project which mates with a wide range of shaft diameters
thanks to the adjustable chuck. we added a dimmer switch to provide better control over the motor speed
but it was ultimately run at a considerable clip. like most ac motors, the drill had relatively little torque at low speeds and tended to stall out under the pressure of 10 gallons of delicious gravy.
Step 2: Fountain Plumbing
with the pump assembeled, the rest of the fountain was plumbed. a large stock pot
heated by an electric burner functioned as the resivoir. a hole was drilled in the side to
accept a sink drain fitting which was potted in with caulk. the spout was another item
from the plumbing isle. the tasteful, minimalist crome pipe was purposely chosen over
the obvious possiblities involving cupids (but only after much discussion). zip ties sealed
the hose to standard sink plubing. a plywood enclosure hid the resivour and hot plate and
provided structure to hold the silver bowls over which the gravy cascaded.
Step 3: Making 10 Gallons of Gravy
step 1: make 10 gallons of stock
- 15-20 pounds chicken bones and backs
- 5 pounds yellow oneion, peeld and cut into 16ths
- 3 pounds carrots, scrubbed not peeld and cut into 1 inch lengths
- 1 head celery, washed and cut into large pieces
- handful of fresh thyme, half bunch of parsley, large pinch of black pepper and 2-3 bayleaves
toss bones and vegtables with vegetable oil and roast in a hot 450 degree oven until rich
dark brown color. place in a stock pot and cover with cold water. deglaze pan with white
wine, bring to boil then lower heat to simmer for 1.5 hours, skimming as you go. strain
stock, chill and reserve for gravy.
step 2: makin gravy
- 2.5 pounds butter
- 2.5 pounds flour
melt butter and add the flour, stirring constantly, until smooth. cook, watching like a
hawk until the mixture is aromatic and colored to your desire.
add cold stock to hot roux to make a smooth paste.
stir until smooth then add the rest of the stock to the pan. roux
does not work until the mixture comes to boil.
bring to a boil and lower to a simmer. add giblets as desired.
simmer for 10-15 minutes and season to taste. seasonings can
be added after the gravy is loaded in the fountain
Step 4: Enjoy
nothing quite like a gurgling stream of gravy. the final rate of flow was probably closer to gushing, perhaps that of two garden hoses. combined with the noise and steam, it made for quite a sight. the dog likely thought it had achieved nirvana.
Step 5: Bonus Fountains
of course there are many other joyous foods deliverable via fountain. the gravy fountain was presented as part of a triumvirate of recirulated pleasures which included a singapore sling fountain and a hard sauce fountain. the latter two, while delicious, involved only fairly mundane application of existing consumer goods.