The Economics of Home Roasting Coffee

A Cost Analysis

I started home roasting with a popcorn machine 6 years ago. I was more curious than anything if I would enjoy home roasting because it seemed buying a roaster would pay off after a few years. So I bought a variety kit and got to work. Turns out, I could save a lot of money given the right roast, but the downside is that I drink more coffee because it is cheaper and better. As a result, it probably costs the same, but I have more control over quality by home roasting.

My first dive into roasting. All images by the author.

To start, I tried the popcorn maker, but it was very slow. I also tried the oven, but it was too smoky inside. I panicked quite a bit when my house filled with smoke, and all the smoke alarms were going off.

When I moved to California, a coworker had just upgraded to a larger roaster and gave me his old roaster for free. It was a Hottop, one model older than the newest. The display was having some issues, and it finally broke after two years. However, I had developed my roast profile in the first year of use. Because I use the same profile every time, I can still navigate to the right spot.

Night Roasting!

Economy of the Bean

The past two years, I’ve been tracking my roasts in more detail, but with email, I was able to go back and look at all the green coffee I’ve bought over the past few years to put together costs per pound.

Here is a sample of my table for my roasts. I have recorded the cupping metrics found on Sweet Maria’s website where I bought most of my green beans.

A sample of my roast data sheet where I also track average Q-grades for the roast based on the each bean’s Q-score

I adjusted the cost per pound based on shipping and an estimated 12% weight loss due roasting. Typically, a medium roast loses 12 to 20% of weight due to water evaporation. On average, I paid $8.42/lbs after shipping and roasting. I didn’t include the electricity because it’s 20 minutes at 1000 watts, paying $0.1 per kilowatt-hour. I plotted the histogram of all the beans I’ve bought, and some times I splurge, but mostly I’m between $7 and $8. This histogram is the final cost per pound.

Typically, coffee is sold as 12 oz bags, and when you cost adjust to 16 oz bags, the price is between $20 and $30 for the same quality of beans that I’m getting.

When looking at quality, the cost roughly aligns with the Q-score which is good because cost should be related to the quality of the bean not just how someone wants the bean to be.

I looked further at the average Q-score for my blends as well as their cost. This Q-score was an average of the Q-scores of the beans going into the blend based on their weight contribution to the blend. There seems to be a decent correlation between the cost and the Q-score for my blends.

Economics of Roasting Equipment

With such a low cost for roasted beans, the pay-off for buying a roaster can happen pretty quick. Based on this cost and the difference with $20/lbs, I looked at a variety of machines to determine when the breakeven point is reached.

I used this information to generate this table below based on how many shots of espresso you drink daily (assuming 14g shots or a standard double espresso). This is based in months because most of the equipment home roasters would buy will pay themselves off in a year or two. I included the more expensive roasters for comparison.

Home roasting isn’t for everyone because it requires more attention to detail and an appreciation to experiment a little bit to be successful. However, home roasting has given me more control and consistency that I wouldn’t have otherwise as well as a better appreciation for coffees from around the world. I’ve become more experimental in what I have tried and the blends I make.

My favorite happy mistake was accidentally taking a roast to the second crack. I typically go 1 minute to 1:30 minutes past the first crack. The trouble with this one is that it was half of a blend. I decided to keep it and try it with the medium roast. It was very interesting mixed and created some pretty images when layered.

If you like, follow me on Twitter and YouTube where I post videos of espresso shots on different machines and espresso related stuff. You can also find me on LinkedIn.

Further readings of mine:

Coffee Bean Degassing

Deconstructed Coffee: Split Roasting, Grinding, and Layering for Better Espresso

Pre-infusion for Espresso: Visual Cues for Better Espresso

The Shape of Coffee

To Stir or To Swirl: Better Espresso Experience

Spicy Espresso: Grind Hot, Tamp Cold for Better Coffee

Staccato Espresso: Leveling Up Espresso

Improving Espresso with Paper Filters

Coffee Solubility in Espresso: An Initial Study

Staccato Tamping: Improving Espresso without a Sifter

Espresso Simulation: First Steps in Computer Models

Pressure Pulsing for Better Espresso

Coffee Data Sheet

The Tale of the Stolen Espresso Machine

Espresso filter analysis


The Economics of Home Roasting Coffee was originally published in Towards Data Science on Medium, where people are continuing the conversation by highlighting and responding to this story.

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