In this guide I’ll show you how to make a DIY cold drip coffee maker for $40.
If you’ve ever tasted cold-brew coffee, you know that it’s damn good. It is much smoother than hot-brewed coffee and has a sweeter and more complex flavor too.
The reason it tastes so smooth is because it is less acidic and bitter than normal coffee. The cold-brew process doesn’t extract as much of the compounds that produce these flavors in hot-brewed coffee.
Less acidity means it is easier on the stomach, too. Many coffee experts claim that cold-brew coffee is about half as acidic as hot brewed. And even if you don’t like cold coffee, you can always heat it up in the microwave before drinking. Beware though, the jury is still out on whether warming up cold-brew alters the taste.
The biggest downside to cold-brew coffee is the time it takes to make it, which can extend over a day if you are doing a large batch. But, if you enjoy the process, it makes the time go a lot quicker. But enough about cold brew, on to the build!
Step 1: The Parts
Below I show where I got the parts for my cold brew tower and their approximate costs. These places are just a recommendation where to find them. You can definitely find a lot of these parts at most hardware stores, and I’m sure you could even find everything online if you wanted to. As far as the costs, you will probably have to buy some of these items in bulk (like the copper) so you may spend more than $40 to make one but it shouldn’t be too much more.
- 3, 2 foot pieces ⅝” o.d. coiled copper tubing (Home Depot) - $8
- 3, 3.75” pieces of ¼” o.d. refrigeration coiled copper tubing (Home Depot) - $0.50
- 3, #0 11/16” (wide end) rubber stoppers for feet (Ace Hardware) - $1.20
- 4” equilateral triangle of 24 ga copper sheeting (Amazon) - $0.75
- 3, ½” copper end caps (Home Depot) - $1.35
Water Bowl and Coffee Grounds Glass
- 1, ~1L glass spherical fish bowl (Wal-Mart) - $2
- 1, 1/8" x 1.5” brass pipe nipple (Ace Hardware) - $3
- 1, 1/8” MIP x 1/8” FIP Needle valve (Ace Hardware) - $7
- 1, 3/8” x ¾” steel sleeve (Ace Hardware) - $0.70
- 1, 5” tall by 3” wide glass or glass jar (World Market) - $2
- 1 paper coffee filter (Wal-Mart) - $0.05
- 1 piece of felt cut into a 2.25" circle (Michaels Arts and Crafts) $0.05
- 4, 3/8” rubber washers that fit tightly around nipple (Ace Hardware) - $1.20
- 2, 7/8” wide stainless steel washer (Ace Hardware) - $0.30
- 1, 1.5” long, 1/8” NPT lamp nipple (Ace Hardware) - $2
- 3, 1/8” NPT round lamp nuts (Ace Hardware) - $2
- 1, ~¼”(narrow end) cork (Ace Hardware) - $0.50
- ~1L glass carafe and lid (World Market) - $6
TOTAL - $38.60
Step 2: The Tools
Here are the tools you'll need to build your cold drip tower:
- Copper soldering materials (solder, flux, brush, emery cloth)
- ¼” drill bit, 1” hole saw bit, 3/8” diamond hole saw bit
- Masking tape
- Tape Measure
- Curved surface to bend pipe over (I use a 1/2" conduit bender handle)
- Bailing wire (or steel wire) to hold tower together while soldering
- Teflon tape
- Clear silicone
- 80 grit sandpaper (optional)
Step 3: Cutting and Bending the Pipe
- Cut 3, 2 foot lengths of copper pipe and straighten as best as possible (use a mallet and a flat surface)
- Sand all pipes with 80 grit sandpaper for polished look (optional). It is quickest to use a belt sander if you have one
- Mark a line at 11” and 17.5” from one end of each pipe. We will call the end that you measured from the “bottom” of the pipe
- Using a rounded surface, bend copper pipes about 4” of deflection on the bottom end of the pipe and 1.5” of deflection on the top end. Bend the pipes a little bit at a time at different points along the pipe. If you bend the pipes over just one spot it may result in a kink. The bending should result in a shallow C shape like shown above
- Cut a 5/16” wide slit at each 11” marked line with a hacksaw. Make sure slits are centered on convex side of pipes
Step 4: Constructing the Tower
- Cut 4.125” equilateral triangle out of copper sheet and file edges
- Hammer dents into triangle in a repeatable pattern. This will add strength to the copper and add a nice texture
- Drill a 1” hole in center of the triangle for the coffee grounds glass bottom to sit in
- Cut three 3.75” supports out of 1/4” tubing. Sand (optional)
- Drill 2, ¼” holes in each pipe at the 17.5” line. The holes should be about ¼” from the center of the convex side of the pipes
- Quickly rough up the following areas with emery cloth to prep for soldering:
- Each corner (top and bottom) of triangle shelf
- Around each slit in each leg ½” from the ends of each support
- Where supports meet legs
Step 5: Soldering the Tower
- Brush a layer of flux on each sanded part
- Lay two legs on a piece of a 2×4. Bottom of legs should touch the work surface
- Insert copper shelf into two legs
- Insert one support between two legs
- Wire tie two legs to hold together
- Make sure everything is aligned
- Solder shelf and support
- Place shelf into third leg and insert remaining two supports
- Wire tie all three legs tight together. Stand the tower up.
- Check alignment and solder remaining joints. Not going to lie, it’s tough to get everything aligned just right. Have someone hold it in place (with thick gloves) if you need to while soldering
- Wipe clean excess flux and let cool
- Polish dark and dirty spots and excess solder with sandpaper
- Place a dab of adhesive on the three rubber stoppers and insert into bottom of each leg. Twist slightly.
- Place a dab of adhesive on the inside of the three copper caps and insert onto top of each leg. Twist slightly.
Step 6: Drilling the Glass and Attaching the Valve
- Drill 3/8” hole in center of bottom of coffee grounds jar and center of water jar with diamond hole saw bit. Use masking tape to start holes so bit doesn’t wander. Keep the bit at an angle at first and slowly move it towards the perpendicular. Use the low speed setting on the drill. Remember to keep jars under water while drilling and don’t put too much pressure on drill. Think of it as “carving” out the glass. For the thicker-bottomed coffee grounds glass, it takes about 10 minutes of straight drilling. If you are using a plug-in drill, BE VERY CAREFUL NOT TO DROP THE DRILL IN THE SINK. Doing so could electrocute and potentially kill you. It’s best to use a battery powered drill here.
- Lightly sand sharp edges
- Apply one wrap of Teflon tape to one side of 1.5″ pipe nipple making sure to wrap clockwise. Insert pipe nipple into female end of valve and tighten.
- Place rubber washer, metal washer, and steel sleeve on one end of nipple
- Place thin layer of silicone on one side of this rubber washer
- Insert nipple into bottom of water jar
- Place layer of silicone on other rubber washer
- Insert other rubber washer and round nut on the bottom inside of the water jar over the pipe nipple. Tighten LIGHTLY. Test for leaks. Tighten a little more if it leaks and test again.
- Place thin layer of silicone on one side of remaining two rubber washers
- Place one rubber washer on one end of lamp nipple
- Place one round lamp nut about 1/2″ from one end of lamp nipple
- Insert nipple through bottom of coffee grounds jar from inside of jar
- Place other rubber washer and round nut on the bottom of coffee grounds jar over the pipe nipple. Tighten LIGHTLY. Test for leaks. Tighten a little more if it leaks and test again.
Step 7: Make Some Cold Brew!
Here’s a basic recipe and instructions to break in your DIY cold brew coffee maker. Remember, it is more art than science to make a good cup of cold-brew. Feel free to experiment with different coffee beans, drip rates, grind of coffee beans, and volumes of coffee and water to produce a cold-brew you love! For more recipe ideas, check out this compilation of cold-brew recipes.
You will need:
- Scale (optional)
- 1 paper coffee filter
- 100 grams (~1 heaping cup) medium ground coffee beans
- 600 grams (2.5 cups) unchlorinated water
- 400 grams (~3 cups) ice cubes
- Place coffee pitcher under stand and water bowl on top of stand. Make sure valve is closed (all the way clockwise) on water bowl
- Pour ice and water into water bowl on stand
- Place felt filter into bottom of coffee grounds glass. Pour in coffee grounds and place on stand. Pipe nipple on bottom of glass should go through hole in stand
- Place cork in pipe nipple under coffee grounds glass
- Cut out a circle about the size of the inside diameter of the coffee grounds glass from a paper coffee filter. Don’t worry about cutting perfectly. This filter will diffuse the dripping water evenly among the coffee grounds. Set filter aside
- Open valve to a steady stream until coffee grounds are fully saturated and you don’t see any dry spots around the sides. Place paper filter on top of grounds
- Wait one minute and then remove cork
- Adjust valve to drip to about 40 drops a minutes. Check every hour or so and adjust valve to maintain drip rate
- Allow 4-5 hours to brew, until water stops dripping. Enjoy immediately or refrigerate
Step 8: More Information
For more information, to ask questions, or to see other awesome DIY food projects, visit SavoryandSour.com!
Runner Up in the
Science of Cooking
robkibler made it!