Introduction: 4 Different Coffee Roasters

About: My latest observation: If you can learn, and use Instructables, and it still doesn't get fixed. It's because you needed it for parts! I have 4 years experience with munitions and such. (Military) I have a…
Here are four ways to roast your own green coffee beans, on the cheap! These coffee roasters may cost you little to nothing.

In the last couple of years I've evolved from drinking pre-ground coffee 'off the shelf', to grinding my own beans, that come roasted 'off the shelf'. Then we moved on to green beans after studying several web sites and their instructions on how to roast coffee, and I found some good concepts for making my own coffee roaster.

Now I buy my coffee in 50 lb. burlap bags, (@ $3.70/lb after shipping), of green,{Estate Java}, beans and roast, and grind them myself.

Since I had already made these simple roasters, I'm not going to de-construct anything. I mainly want to show everyone some simple roaster ideas to help give you some ideas to build a better roaster, or to build your first roaster. Much depends on what you have to work with. I'm one of those people who sees potential in all kinds of things. Yep I collect junk! As Mrs. Bob might put it.

So depending on what you have stock piled that can be used, your roaster will be different but still be fully functional.

Also I don't talk much about tools because before you tackle any project the standard hand tools should already exist. I'm not beyond the flea market cheapo tools they are fine for light duty. And since your roaster probably will be different the tools may vary.

I prefer to use hot air to roast the beans. And since the popcorn popper conversion has been done several times, I was inclined to use my resourcefulness and look at other possibilities.

So far I have 4 different roasters that I have roasted with, and like.
I am posting this to give other coffee lovers ideas for building a roaster of their own so they can have excellent coffee at an affordable price. I have not had a bitter or otherwise bad cup of coffee since I started roasting.

Please note: I do not instruct you on the roasting of coffee beans in this instructable, There are plenty of web sites with good advice on this. Do some research. Or check out
This dude: sysiphus, seems to have a good handle on the roasting process. And since he's already covered roasting, check him out! Also he has yet another method of roasting as well.

Step 1: Don't Even Think of Roasting If You Can't Grind the Beans!

The first thing I was going to need was a grinder. I wasn't up to hacking one together, at least not until I figured out what parts I would have to procure. Our first grinder, was a cheap,(under $20) blade grinder. and we were buying pre- roasted "Whole bean" coffee at Wal-Mart. That was the beginning, I knew then that I was never going back to coffee that was ground, who knows when?

After about a year of this, I began to learn that "Green coffee beans" of quality could be easily bought over the Internet much cheaper than the pre-roasted, "Blended" coffee I was getting.

It was on!

First on my list was a burr type grinder. Burr grinders do a much better job than the cheap blade grinders For one, I was never pleased with the results of a blade grinder,(chopper). Burr grinders seem to crush the beans evenly, and it is much easier to get a good even grind on any setting from fine to course.

I did hours, and hours of research before I decided on a Krups burr grinder. The one pictured came from
It set me back $49.99 w/free shipping. I don't regret spending one dime of that money.

Later I found the hand crank one for $3.00 at a flea market. I can take the crank off and chuck a battery powered drill to it and save allot of time compared to using the hand crank, I used it once when the power was out. I heated our water in a pan with a propane torch, and poured it over the grounds in a filter. Also the hand crank grinder has a wider range of adjustment. I can set it so course that it barely crushes the beans, our I can turn the beans into dust. If I had found this before the Krups, I'd never have ordered the Krups. I'm glad that things worked the other way.

In short: Cheap blade "choppers" work and can be used, but burr grinders rock!

Step 2: About Coffee Roasters

You can buy a good manufactured coffee roaster, but the cost is outrageous to me! The top end home roaster is way too much, dollar wise! Even the cheap roasters are unacceptable to me! $80 or more after shipping and only one or two pots of coffee per roast! Give me a break!

The concept of building a roaster isn't complicated really:

1) Pretty much any roaster has to have a method of agitation, to keep the beans moving and roasting evenly.

2) The roaster or roasting system has to be able to heat up to over 500 degrees or more, to compensate for the cooler air around it.

3) The heat has to be controllable. Most roasting tutorials I've read claim it's best to roast with a 'roasting curve', or something like that. What I mean is that sometimes during the process you should ease off the heat and let that portion of the roast, proceed slower than other portions of the roast.

4) Cooling is very important. The faster you can cool the beans once they are done roasting, the faster you stop the roasting process. These beans seem to hold heat well.

The next thing I have to include pertains to anything you try to conceive or build.

5) The K.I.S.S. principle:
Keep It Simple Stupid!
In the engineering world it means, Don't over think things. Keep things as simple as possible.
Just Google: "Kiss principle" and you should find enough explanation on this. And as a type of weekend engineer, I have found that it can save you a bunch of time, and frustration if you don't try "over engineer" your project.

Also it's good to remember that, 'You have to learn how to walk before you try to run!' This is how these roasters are presented. Except for the the one in step seven, I only fixed up a basket for it.


Step 3: Super Simple, But I Still Use It.

My first roasts were simple and small. The first few times I roasted with a small flour sifter and a heat gun. This was a step in the right direction and we liked the results, But I knew it was not quite right. The beans weren't cooking evenly. I don't recommend this at all.

Next I decided to get the wire strainer baskets shown below. I found that by spinning the baskets with one hand over the heat gun I could roast about 1 pot worth of beans evenly and to any degree of roast I wanted. This was a good way for me to learn the basics of roasting coffee beans. I still use this basket system to roast my, ($18.50/lb), Kona.

When I get the beans roasted the way I want I just dump them into an aluminum cake pan and shake them to cool and blow off the chaff.

I fill the bottom basket half full of beans, they do expand a bunch by the time they are done.

Mrs. Bob, would not let me roast more than one small batch at a time in the kitchen, so most roasting was done on the porch. That meant that I had to watch the weather too. We drink 2, (12 cup), pots of coffee a day or more depending on the season. I still needed a bigger system as it took 16 batches to get one weeks worth of roasted coffee.

Step 4: The Great Thermos Adventure!

Next was the great thermos adventure!

I had bought about 10 thermos Bottles over the years at yard sales, I think I've got about $20, invested in all of them. I came up with the idea to use a thermos for a roaster from a combination of other projects that I found on various web sites.

This system allowed me to roast twice as many beans per roast. Plus I set up my first ventilation system, crude, but winter was coming and I wasn't going to be able to roast on the porch much anymore. My first few roasts actually happened on the porch, and it was much easier to heat up the beans.

The little basket system can be done in the house, but it isn't recommended. Anything more than a small roast, and the smoke gets way too bad to do indoors without ventilation. The stove exhaust system won't do it, unless you have the new 'Binford 6200 super sucker' and you probably don't! You will need a ventilation system. The system shown below is a classic example of my engineering abilities!

The wife and I actually like a good whiff of the smoke to impregnate the kitchen some, it smells like morning all day long. But too much isn't good, trust me! I've been there.

Note: Stanley Thermos bottles have a charcoal liner inside, not good for this project.
Other types may also have some kind of medium as an insulator, also bad.
The 'Thermos' brand seems to be free of insulator material. At least this one was.

I removed the plastic bottom using my heat gun to soften the glue. About all I did to the thermos was drill a hole in the center of the bottom big enough for a 1/4"x20 bolt fit through. The bolt was 4" long but the threaded area is only 1" long. I ran a nut all the way down the threads followed by a washer. Next I put the bolt into the end of the thermos. Then I put a washer and nut on the end of the bolt. I used a socket, long extension, (or several short ones), ratchet, and a pair of pliers to tighten it up. Also I ground the head off the bolt so it would chuck up better.

The drill I used first, the one shown below, is a corded drill, meaning that you have to plug it in the wall. The drill was always needing speed adjustment, as the power fluctuated. I was surprised at how much the electricity fluctuated. I found that a battery powered drill was much better. I already had one, and it was less effort than making a regulator. It is much smoother, set it once and it's good to go.

Also I was still using the cake pan to cool the beans and blow off the chaff.

Step 5: The Space Heater Roaster

My next roaster was made from a partially de-constructed space heater.

Before you attempt to re-engineer any appliance, make sure that it is unplugged. Make sure you understand the changes you are making. Electrical re-engineering mistakes can be *SHOCKING* to say the very least!

Again I doubled my roasting capability, and now could roast 1 weeks worth of beans in 4 roasts.

A few simple alterations need to be made to a space heater internally. Mostly you have to bypass the thermostat, and put a switch inline with the fan so that it can be used when needed. Also a switch for the heat is good to have. I was very happy with the original version but it was flimsy in the hood area. I made the first hood from an aluminum cake pan. Now this roaster in on the shelf until I find a better covering setup. I started to make one out of galvanized stove pipe but I'm also keeping my mind open for other options and inspirations. I really don't like not seeing the beans while they roast. I have a piece of glass from a de-constructed microwave and am contemplating using it. But again this is on hold for now. But it is a backup.

The basket that I made is two pencil baskets I found at Wal-Mart.

I drilled holes in the center of the bottom of each basket, then roasted them to a glowing red state, with a propane torch, to burn off all undesirables, and scraped and cleaned them up after they cooled.

You can see the complex axle assembly too!

I used a drill to turn it.

Also with this roaster, the way the drum is designed it is hard to open. So I had to break out a blower I had. I turn off the heat when the beans are done and blow cool air on them while they are still rotating until they have stopped cooking. Then I have to let everything cool to the point I can handle it. The latch is hooked and unhooked with pliers as the spring is strong. Plus I have to remove one axle bolt to empty and fill the drum.

When I overhaul this roaster I will do an instructable on it as I go. I want a bigger and better drum for it, I'll be keeping and eye out for things that might work.

Step 6: Ventilation

In order to continue to roast indoors I had to re-invent my exhaust system as the other one was not going to fit this next roaster. Anyway I was tired of reshaping it every time I took it back out for use.

I needed some shelf space anyway, to store procured items awaiting reconstruction. I built a set of shelves from plywood 2'x8' long. each shelf is supported by 4 concrete blocks, and it,s three levels high. One end of the shelves was positioned by a window.

Staples hold the insulation to the wood. Duct tape holds the rest together.

Another thing to point out. My exhaust blower has to be operating the whole time. This insulation is plastic, so it will soften as the heat rises. But the smoke has to be drawn out anyway so it works out.

Step 7: The Ronco Roaster

Finally, I got a rotisserie oven! It's a compact model, but it was free so I was sold.

I now roast twice a week, which is about right for us.

Now the first rule I had, was I still had to be able to use this oven to cook food as well.
This oven is also still great for roasting meat and such, I just clean it good as soon as I'm done cooking anything else in it. I've cooked a turkey breast, pork loin, and a batch of coffee all in the same day.

The basket shown was made from a de-constructed wire mesh waste basket, I got from, (you guessed it!), Wal-Mart for under $8. Where ever you get the mesh material, keep in mind that the holes should not restrict airflow, but not be large enough to let the green beans fall out.

I used pair of dull scissors to cut the wire mesh, they were not a large pair, but I was surprised that they did the job. I cut the top rim off first, then down the seam, then around the base. Next I worked the mesh into as flat a panel as I could. It won't be straight, it's going to have curvature.

I made a big hot fire in my outdoor grill, and got all the screen almost molten, then cooled and cleaned it. All parts used to make the basket were super heated and cleaned. Once the wire mesh has cooled from being super heated it is easier to work with. But you should wear gloves and a long sleeve shirt because the little bits of mesh on the edges still snag and poke.

I already had the end plates. They came from an old tractor air filter I had. After they were given the blazing hot heat treatment, I used the rods on the spit to mark were I needed to drill the holes for the rods to slide through. Also I had to scrounge up some fender washers and bolts to plug the unneeded center holes.

Then I put the end caps on the rods, put the spit together and measured for the width of my screen. Mine was 8.25" wide. This mesh panel should be cut at least 9 inches longer than the circumference of the drum. This will allow you to fold in the 4 one inch fins that keep the beans moving, mixing, and roasting evenly. My circumference is about 16 inches, so I made a 1inch tall fin every 4 inches. Crimp the fins with pliers to help shape them. If all goes well there should a fin at the start of the mesh panel and 3 more folded fins, plus about 5 inches of mesh panel past the last folded fin. when rolled into a cylinder there should a 1 inch overlap of the mesh to make a seam.

Then I used some thin brass wire I had to sew the ends together. Needle nose pliers helped with this.

Step 8: And Lastly...

Before you actually roast with a basket, make sure it won't lose any beans. Put a batch of beans in the basket,(1/4 - 1/3 full), and rotate without heat for several minutes. This will show you most any problem that the basket may have.

Some things to consider when ordering green beans:

I always add the cost of shipping to the cost of the beans and divide by the pounds of beans to get the cost per pound. This cost per pound is very influential when I'm looking to buy green beans.

A first time roaster shouldn't be afraid to order 5 lbs. of one type of coffee to start, I suggest to search for sampler kits of green beans. Some sites do offer this.
This is where I started out. I ordered 5 different 5lb. bags, free shipping with 25lbs or more).
They have sampler packs as well.

The next address is where I ordered my last 50lb bag of coffee.

The Kona coffee came from:
I purchased 2lbs. and we enjoy this expensive coffee once a month or so.
My next exotic coffee will probably be Jamaican Blue Mountain. The buying of expensive coffee is very limited in our budget.

And you might want to check into "Kopi Luwak", or "Civet coffee". This is the most expensive coffee in the world according to what I've read. But if you look it up you'll see why the Bob family won't be ordering any! The process that these beans go through before shipping is different, I must say!

I hope that I have been able to give you some ideas, or inspirations.

And please rate what you have read, please rate it for me.

Thank you very much.


Step 9: And a Follow Up.

I had posted this in response to a comment below, but I figured that I'd go ahead and add it in a step.