Coffee Roaster - popper*

October 3, 2021October 3, 2021

Popper Deconstruction: Inside an Air Coffee Roaster

A very basic video about making and testing Popper, the air coffee roaster.

Here’s a video to show a few early versions of the machine, and some aspects I had to deal with in getting this project completed.

I don’t think this is a video of general interest so please don’t expect much, and the quality isn’t great. I was trying to move the camera phone around to show details and didn’t always do a great job. Ugh.

Also I need to make it clear that you shouldn’t do what I do here, because opening up the machine voids the warranty against manufacturer defect. I made the video to provide some background details only, and show how I test temperatures.

Some things I go over here are
A look at an early prototype
Location of the thermal cutout switch that protects Popper from overheating
When I have a unit that turns off before reaching dark roasts, how i move the thermal cutout switch upward to solve the issue.
How I use a thermometer to probe the bean mass
Show a bare version with probe locations for input air and bean temperatures
Deconstruct (partially) a Popper to show how it’s put together
Talk about the unit that easily roasted 140 grams, and why I couldn’t get it built that way 😢

PS – this is in my workshop space where I store the pallets of Popper, hence the motorbikes and cars and such.

Inside Popper Coffee Roaster

March 4, 2021March 4, 2021

Some things take time, like manufacturing a coffee roaster …

popper*, the coffee roaster was right on the verge of going into production.

… but one thing just wasn’t right. The factory had sent sample after sample, but the fan speed (and therefore the air flow) was not consistent. This impacted the potential batch size.

A late night video chat with the engineers in China made it clear to me though. They were testing under the principle that the roaster should not use the entire pre-programmed roast cycle of 7 minutes. They thought of 0 to 7 as a range so they were presupposing what I wanted was a 4 minute roast!

Well, a 4 minute roast is easy in a popper, but it’s rarely an ideal roast time. In fact, the whole idea of *popper is that the user can fluidly adjust roast time up or down on the fly. It’s a manual, low tech machine, unless you want to get in there with an arduino interface etc.

It’s a machine that rewards people who want to play around with the variables, so it’s simple to do a 7 minute roast just to first crack and add 2 or 3 minutes for development. You just have to be there and tend to your roast, make intuitive decisions and turn a knob. Simple.

(For me I actually feel the 7 minute pre-set roast time can work very well. For City roast I target 5:30 to hear the start of first crack, and the remaining 1:30 for further development. Remember, roast time is relative to the device and the type of thermal transfer. Higher air flow and more movement of the mass means more rapid levels of heat transfer via convection.)

May 8, 2020

Origin Story #1

We wanted to create a coffee roaster, one that was a lot like a popcorn popper from the ‘70s. We didn’t want to think up any new design, or new roast method. We wanted to take what works, the air popcorn popper, and roll it back to the way it was 30 years ago.

So we took an old vintage air popper machine we bought at a thrift store in the ‘90s for $4, and sent it to China. We sent it to the factory that still makes air poppers, and asked if they could make one just like that. They said they could.

West Bend Poppery, first version, 1500 watts

They sent us back a prototype machine. It looked just like the popper we sent them. Actually it was the popper we sent them, but they added 2 knobs to the front.

From then it was a long (and actually pretty boring) back and forth between Oakland and the factory.

There’s more to tell… but we are trying to drag out the story and make more “content” out of this.

May 4, 2020May 4, 2020

It’s a “coffee roaster”

This is just a photoshop image of the Popper with the color shifted from black to gray and the name inserted.

It’s larger than we thought but actually about the same size as the first generation Poppery air popper we sent to them. Big also means stable, which I guess is good.