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DIY Coffee

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DIY Coffee collects five hot MAKE magazine projects to supercharge your java:

  • Home-Built Coffee Roaster
  • Bottomless Espresso Portafilter
  • Toaster Tea Popper
  • Perfect Espresso Temperature Hack
  • Web-Fired Coffee with X10 Automation

Got a jones for caffeine and technology? Mod your espresso machine to dial in the perfect shot, with precise temperature control and a filter hack that kicks out maximum tasty crema. Roast your own with a hand-built custom coffee roaster. Hack a toaster timer to perfect-brew your tea every time. And fire up your coffee pot from the internet using X10 automation. Using home-grown techniques and off-the-shelf parts, caffeine junkies will find everything they need to overclock the fix from their favorite shade-grown beverage.

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11 Slices

Format Buy Remix

The Nirvana Machine

ePub

By Larry Cotton

Photography by Larry Cotton

Lots of folks think that quaffing a cup of coffee from boutique beans comes close to nirvana, but roasting your own beans will bring you even closer. Thats why I call this roaster the Nirvana Machine.

I didnt drink coffee for most of my life, and I even survived without it in the Navy. But when my son introduced me to a cup of legendary West Coast java (OK, Peets), I began to understand what all the fuss was about. Soon, I too became fussy about excellent coffee.

Beans lose flavor after theyre roasted because all of those delicious but volatile aromatic compounds dissipate and break down. Roasting your own beans guarantees ultimate freshness, putting all the flavor into the cup; you will not drink fresher, more satisfying coffee!

Home roasting is easy and inexpensive. Top-quality green beans cost less than roasted beans and have a much longer shelf life. You can have fun fine-tuning your roasts darkness and developing your own blends. Indeed, a growing selection of countertop roasting appliances are now sold, but theyre pricey, non-portable, and very noisy.

 

Java Implementation

ePub

Illustrations by Tim Lillis

The Nirvana Machine uses a battery screwdriver to tumble beans over a camp stove. Unlike commercial machines, the basket is tilted and open-ended, which makes it easier to load the beans and to see and smell their progress during roasting.

When you roast coffee, sugars caramelize, water vaporizes and makes the beans expand, and aromatic compounds are produced, including the ones shown above. The compounds develop at different rates, so varying the roasting time and temperature lets you balance which you want more or less of, to determine the resulting flavor.

The Version 1 basket was a cheap strainer, but the beans broke through that and caused a fire!

MATERIALS

[A] 1 square stainless steel wire cloth, .025 wire diameter Do not substitute. McMaster-Carr part #9238T523 mcmaster.com

[B] Unpainted aluminum flashing 1010.010

[C] Battery-powered screwdriver I used a Black & Decker AS600.

[D] 1 piece of aluminum, at least 4 long Cut from McMaster-Carr part #6023K231

[E] aluminum bar, 3 long Cut from McMaster-Carr part #8975K833

 

Build Your Coffee Roaster

ePub

START

Time: A Weekend Complexity: Medium

1. MAKE THE METAL PARTS

This project has blueprints with complete measurements of all the parts at makezine.com/08/coffeeroaster. Start by downloading and printing them all. Then you can easily follow along and make the metal parts, the wood and plastic parts, and the bean basket.

1a. For the support plate, saw a piece off of the 3 aluminum bar and drill and tap 12 holes as shown in the support plate blueprint. File the cut surface smooth after this and all other cuts.

1b. Clamp the plate in the vise between two 24s and use the C-clamp to bend it widthwise, from the bottom, to an angle of about 127.

You could also start by making the basket (Step 3, page 117). Thats the hard part, and then you can go back and make the other parts to fit afterwards.

1c. To cut the height adjustment slot, drill four or five or holes as close together as possible, then saw or file the slot until its even.

1d. Make the drive shaft bearing. Drill a hole in one end of 1 aluminum bar, then saw or drill and file the slot in from the end. Saw the piece off the bar to measure 1 its easier to machine the slot before trimming the bearing down to final size. File the cut end smooth, and drill and tap two 6-32 holes.

 

Roast Your Coffee Beans

ePub

Take the Nirvana Machine to a well-ventilated place, preferably outdoors.

Make sure the batteries are fresh, and put a drop of oil on the shaft bearing.

Load up to cup of green coffee beans into the bean basket.

With the burner off, switch the screwdriver on and observe the beans rotation pattern. The 3 ribs inside should cause the beans to tumble nicely. The bulk of the tumbling beans should be centered above the burner. Green beans expand as they roast, so they should stay well away from the opening, to leave room for expansion.

If the beans tumble properly, light the propane burner and set the gas-flow knob on low. The beans should begin to yellow in a couple of minutes, and should roast in 10 to 15 minutes.

Never roast coffee unattended, keep kids at a safe distance, and use plain old common sense.

As the beans darken, they will make cracking sounds and shed thin, parchment-like chaff, which drifts out of the opening, making somewhat of a mess. To me, this just adds charm to the experience, but your significant others opinion may vary.

 

2. The Bottomless Portafilter

ePub

Photograph by Will OBrien

Mod your espresso makers filter holder for a tastier cup. By Will OBrien

In my office at home, one end of the room is devoted to computers, electronics, and my assorted projects. The other is the home of the holy grail of caffeine: my espresso bar. Thats where I measure, grind, and tamp my way to produce some beautiful espresso. Ive been tuning and tweaking my setup for the last six months or so, and theres no end in sight. My most recent modification involved some power tools and my portafilter.

The portafilter is the chrome-plated coffee filter holder that most people only notice as the spent grounds are being beaten from its shiny grasp. In this case, I drilled, cut, and ground out the bottom of it to get whats known as a bottomless or naked portafilter.

No stock machine comes with a bottomless portafilter. The modification can sometimes result in espresso going in strange directions like the wall on the other side of the room. The only side affect Ive observed is a tiny amount of spatter on the top of my espresso cup. So why go bottomless? For some, its simply so they can fit a triple basket in the stock portafilter. The espresso industry refers to the bottomless portafilter as a training tool. You can even buy your own from espressoparts.com. As a training tool, the bottomless porta-filter is excellent for checking your tamping technique. As an espresso machine modification, Ive found that my espresso has increased crema, better mouthfeel, and its just tastier.

 

3. Toaster Tea Popper

ePub

Photography by Johnathan Nightingale

Perfect brew by the clock. By Johnathan Nightingale

I didnt used to care about tea timing. In general, I have found that I can prepare tea of adequate quality by simply leaving the teabag in for a while. Recently, though, I was persuaded to begin timing and have been convinced that doing so yields a better and more consistent brew. Conventional tea timers have a common failing though, be they hourglass, mechanical, or, in my case, Palm: they require user intervention. At work, I inevitably became distracted by a conversation or got called away to fix something only to return to a patiently beeping timer and some very overdone tea. What I needed was a timer that could remove the teabag on its own.

I found my salvation in a toaster. A toaster is, after all, an easily obtainable and very cheap device that has, at its core, a variable timer controlling a mechanical lifting arm. Most modern toasters use a simple electronic circuit: when the lever is depressed, current flows to the heating elements and to an electromagnet. The electromagnet holds the lever down against the tension of a spring in the handle. While the toast is toasting, a trickle of current flows into a capacitor at a rate controlled by the darkness dial, which is nothing more than a variable resistor or rheostat. When the capacitor is filled, the electromagnet disconnects, the lever pops back up, and current is cut to the heating coils. With all this work already done for us, a basic ability to solder and some simple parts should be all thats needed for this project.

 

PID Basics

ePub

Photography by John F. Murphy

Get consistent shots by adding precise temperature control to your espresso maker.

By John F. Murphy

The art of espresso making is fraught with many variables coffee bean origin and blend, degree of roast, fineness and consistency of grind, tamping force and technique, and on and on and on. The temperature of the water used to brew the shot is one of the most important variables. In most espresso machines, the brew temperature is controlled by a wildly inaccurate thermostat.

However, control over the brew temperature is key to espresso quality. Different blends of espresso beans and different degrees of roast develop different flavors when brewed at different temperatures. Malabar Gold may taste sweet at a temperature that makes DSB taste sour. Control over the brew temp allows the skilled barista to coax the best flavor from each blend and each roast. In a stock Silvia espresso maker, relative brew temperature is roughly guestimated by time surfing, or pulling the shot a certain number of seconds after the stock thermostat turns on the heating element. Surfing does work, but it requires careful attention and lacks accuracy.

 

The Rancilio Silvia

ePub

If youre going to be finicky enough about your coffee that a few degrees variation in brew temperature is a big deal, youd better start off with a decent espresso machine. The internet is replete with raves about Rancilios Silvia, so Ill just touch on one key feature: temperature stability. Silvia contains a lot of heavy brass in the boiler, the grouphead, and the portafilter. Once all that brass gets up to operating temperature, it tends to stay there.

When you pull a two-ounce double, the hot brass of the grouphead and portafilter keep the brew water from cooling off before it hits the coffee grounds. Likewise, the brass boiler stays hot even as cool water from the reservoir replaces the water used to make the shot. Without good temperature stability during a shot, accurate temperature control is useless, if not downright impossible.

PID Shopping List

Fuji DIN PID controller

PXR3-RCY2-4V

TTI Global

$129.00

Solid-state relay (230V/40A out, DC in, zero switching)

RS1A23D40

TTI Global

$26.00

Type J thermocouple, washer probe, at least 30" long

 

Installation

ePub

Note: I did not actually follow these steps in the order presented. I did a lot of trial fitting, testing, etc., before I arrived at the final assembly. But if I had it to do all over again, this is the way I would do it.

1. Prepare the enclosure. Fitting the PID into the project box was a bit tricky for someone of my limited craftsmanship. The screw towers and circuit board holders in the enclosure interfered with the placement of the PID. I ended up cutting a slot through one end of the enclosure with a hand miter saw and a coping saw. The distance between the circuit board holders molded into the enclosure is very close to the height of the PID, so I simply cut down along the circuit board holders, broke out the piece of plastic between the cuts with a pair of pliers, and reamed out the opening with a power drill until the PID fit.

I also drilled a hole in the back of the enclosure to run wires to the PID and a hole in the top towards the back to mount the (entirely superfluous) lighted rocker switch. Actually mounting the PID in the enclosure is simple enough once the opening is prepared: slip the white mounting collar over the PID, slide the PID into the enclosure, then cinch the mounting collar up tight against the inside of the enclosure. This is easier to do than it is to describe.

 

Tuning

ePub

In order for the PID to work its magic, various parameters must be set on the controller itself. Fortunately, the PID controller takes care of the hard parts through a process called autotuning; through trial and error, the PID determines its own optimum settings necessary to hold the boiler at the desired setpoint. There are a few parameters, however, which need to be set by hand.

Make the following settings by hand. There are about 50 parameters that can be set manually; I only changed 5.

1. Primary Menu: Press and hold SEL key for 3 seconds. The only item of interest on the primary menu is autotune, which is discussed in the autotuning section below.

2. Secondary Menu: Press and hold SEL key for 7 seconds.

TC (cycle time): I have mine set to 1.

P-n2 (input type): Make sure this is set to 2 for type J thermocouple or 3 for type K.

P-dP (decimal point resolution): Set this to 1 to display temps in one-tenth degree increments.

3. Factory Presets Menu: Press and hold SEL for 9 seconds.

P-dF (input filter constant): This setting filters out quick changes in thermocouple readings and slows down PID responses, which is a bad thing for our application. I have mine set to 0.

 

5. Automate Your Coffee Pot Using X10

ePub

Illustration by Damien Scogin

What good is a coffee pot if it cant be controlled from the internet? By Dave Mabe

If youre anything like most geeks Ive met, you probably have a coffee pot that gets a lot of use catering to your caffeine addiction. I decided to play around with X10 technology and an open source software program called MisterHouse to automate my coffee pot and make it more user friendly.

I wanted to wake up to freshly brewed coffee, and Im too lazy to remember to turn off the pot after a period of time to prevent burning. Sure, you could buy a fancy coffee pot that has some of the features I wanted built in, but even the most expensive coffee pot cant touch the flexibilities you can create with a little Perl code.

MisterHouse (misterhouse.net) runs on Windows, Mac, and Linux, and lets you write simple Perl code to control a variety of hardware. To control your coffee pot, youll need to buy an X10 PC interface and an appliance module (less than $50 new even less on eBay). Youll plug the appliance module into the electrical outlet and the coffee pot into the appliance module. Youll need a coffee pot with a mechanical switch it needs to be able to be turned on and off simply by controlling the power supplied to it. The PC interface connects to a computers serial port and plugs into any electrical outlet.

 

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