Mark Frauenfelder - DIY Coffee

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.

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!

Set Up

MATERIALS

[A] 1 square stainless steel wire cloth, .025 wire diameter Do not substitute. McMaster-Carr part #9238T523mcmaster.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

[F] A few inches of adhesive foam weatherstripping

[G] Single-burner propane camp stove The Century 2058 Trail Scout is best.

[H] Simple on-off (SPST) switch RadioShack part #275-701

[I] 2 insulated wire, 22-gauge minimum Telephone cable wire works well.

[J] Twin D-cell battery holder RadioShack #270-386

[K] D-cell alkaline batteries (2)

[L] Two pieces of acrylic or other hard plastic, at least 3 square each, one thick and the other thick Cut from McMaster-Carr part #8589K41 and #8589K81

[M] brass brazing rod From a welding supply house

[N] Scrap plywood 88

[O] Matching 1 long carriage bolt, washer, and knob, threaded

[P] Matching long machine screws, washers, and nuts, 6-32 threaded (16)

[Q] Matching 3 long hex-head bolt and nut, threaded

[R] Uninsulated wire, 24-gauge solid McMaster-Carr part #8870K16

[ NOT SHOWN ]

Standard 16.4 oz disposable propane cylinder long machine screws, 6-32 threaded (4)

Wood screws, long flathead #10 (2) and long #6 (8)

Scrap 18 lumber or plywood At least 18 long

Scrap wood block About 6 cube

8 wood or plastic dowel, diameter

Wood glue or 5-minute epoxy

Paper For templates and caution label

See a list of tools for this project atmakezine.com/08/roaster .

Build Your Coffee Roaster

Make It

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,