Sample roasting in a popcorn maker

Whether you are a small roastery like us or a coffee enthusiast (where your love of coffee may have got out of hand) you may need to roast green beans in small quantities occasionally.

This problem arose for us as we look to expand suppliers and find more niche specialty coffees. We are often sent green beans, usually straight from a company, that may sell for a collective of coffee farms from various countries, meaning they don't have the facilities to roast small quantities of beans for their customers to try.

As much as we would love a high spec sample roaster, if you have seen the new Ikawa ones, you will know what I mean, they look beautiful. However they come at a huge cost (£750-£1000) for something that won't be used regularly.

Our roaster sent me a link to Sweet Maria's (a great site with a wealth of knowledge about coffee roasting) for an affordable sample roasting option  a popcorn maker!

So we splashed out £12.99 (+£4.99 P+P) on a VonChef Air popcorn maker. I chose this one as it matched the wattage recommended by Sweet Maria,1200w.

After 30 minutes reading up on roasting and watching a couple of YouTube videos I felt like a sample roasting expert and thought I would give it a try. After a few practice roasts and trip ups here are some basic instructions, with a few tips and tricks to help you along the way.


Above you can see some of my basic equipment:

(AIR) Popcorn maker, 1200w, aluminium inside.

Extension lead, trust me you want to be doing this outside. Also preferably an industrial extension lead to maximise wattage or the popcorn maker can over heat and switch off too quickly.

Wooden spoon, for the handle as a stirrer.

Metal sieve, to quickly cool the beans.

Green coffee beans, of course.

Sample trays (or a tupperware) to let be beans cool completely.

Scales, to weigh the amount of beans you will need.

A few roasted coffee beans, handy to compare the final colour.


- First things first, its a quick process so make sure you have everything around you ready to go.

- Green beans, quantity - 80g to 100g depending on bean size, the bigger the bean the less you need.

- Weigh out your beans, after the first few times you will get the jist of what works best.

-Turn on your popcorn maker, wait about 10sec they heat up incredibly quickly, and throw in your weighed out beans.

- They should almost immediately start moving around inside the popcorn maker, about every 15sec give them a stir with your wooden spoon handle.

- Keep watching them, they start to get pretty smokey and chaff is flying around they are moving towards the 'first crack' and they will start to pop around, you might lose a few!

- Have your sieve at the ready, note the colour is close to your roasted coffee beans you have as a sample to compare, and quickly tip them out of the popcorn maker into the metal sieve.

- Keep them moving in the sieve, it is imperative to cool them down quickly otherwise they will keep cooking.

- When they are cool to the touch, about 5mins, you can pour them into the sample tray/tupperware and let them cool completely before placing them in an airtight bag preferably with a valve.

- Finally when they are cooling take a good look at your beans and pick out any irregularities as you would in a regular roast. They maybe slightly lighter or darker in colour as the roast is so short or an odd shape. But as it is a small sample roast, it isn't too arduous to pick out the irregular ones and you are left with your successful sample roast!

And that's it! The first couple of times you feel like you are juggling the beans a bit, but after a couple of practices you will be a sample roasting expert.