Roast your own coffee beans??

Yes, you CAN roast your own coffee beans, at home,

using a Gene-Cafe, Nesco or Hot-Top roaster

or ... you can build_your_own home-coffee roaster!

I remember walking into a grocer's shop, many years ago... it was one of those '60s era ones: starting to sell some self serve stuff, but still with a counter where the grocer would weigh out cheese and biscuits and such.

This particular shop also had a coffee-roaster, and every Monday and Thursday the grocer would be roasting coffee.
The incredible aroma of roasting coffee beans, ranging from the sweet, almost hay-like scent of the first heat to the nutty smoke of First Crack, and then the caramel of Second Crack... it was wonderful.

When I started roasting coffee, it was not out of nostalgia, but sheer necessity: we could not get freshly roasted coffee where we were, and home-roasting was the only option.

However, once the first batch was in the roaster, all these "scent-memories" came flooding back and i was back in the grocer's shop, watching in awe as he tipped out the beans from the roaster into the cooler, stirring them gently with a spatula.

And that was it....roasting our own coffee-beans: I was hooked!!

There are many ways you can roast coffee beans, but they all have two things in common: heat and agitation.

Coffee beans develop their characteristic flavour and aroma under the influence of heat; the duration and degree of heat applied to the beans can vary, depending on the variety of bean used and the required roast level.

But, as with all vegetable matter, too much heat at one spot will overheat the fibres, causing them to burn.... and you will end up with charcoal.

So, apart from heat, you will need some form of agitation.

Let's list the various "build-your-own" options:

Build your own :
Corretto-, BBQ-style-, Turbo-oven-, Oven-Popper- or Stovetop- style coffee roaster !!

Stove-top roasting:

Dedicated stove top coffee-roasters: pottery griddles or heavy, lidded pots with a crank which stirs the beans.

Frying pan and spatula: put the beans in a heavy frying-pan, heat gently whilst stirring with the spatula.

Stove-top popcorn makers with agitator.

With these options you will have a bit of trouble controlling the temperature AND you will probably generate smoke, as the chaff will remain on the griddle/in the pan with the beans.... perhaps only an option for indoors if your rangehood-fan is quite powerful!
Good fun to experiment with, with very drinkable coffee as result.

BBQ style coffee-roasting:

Basic principle: rotating (stainless steel) mesh drum over BBQ heat source; the more complex versions are making good use of the rotisserie motor, the simpler versions have a hand-crank.

Advantage of this style of roasting: the "do it your self " nature of the style: you can make your own drum, or have it made by a local engineer,
Also, the size of the batch you can roast ( 500gm or more) and the relatively easy control of the heat source.
Negatives can be the "out door" environment, with the weather influencing the roast-profile, and the chaff which can remain in the drum, causing smoke in the drum, which may affect the flavour of the beans.

Corretto-Style Roasting.

Basic principle: the beans are roasted in the pan of a bread-maker: the bread-maker paddle rotates the beans, while a hot-air gun ( heat gun) , mounted in a

drill-stand and aimed at the beans in the pan, is providing the heat source.

This style of roasting has been named after an Australian CoffeeSnobs-forum member, Corretto, who devised the system which has been acclaimed as one of the best "make your own" home coffee roasting methods.
The addition of Thermocouples, Roast-monitor software, extraction fans etc. can turn this type of set-up from "back-yard" to very sophisticated.
The level of roast control can be very high, and the quality of roast produced by a skilled Corretto roaster can be excellent indeed.
However, it is, once again, a roast method best done outside, mainly because of the chaff, which is blown about by the hot air gun.

"Turbo-oven" style coffee-roasting.

Basic principle: roasting the beans in a container (pot, pan, bowl) which has a rotating paddle (manufactured by the home-roaster, or using one from an old pop-
corn maker base) atop which a "Turbo-oven" hot-air unit has been mounted.

After installing a Thermocouple in the bean-mass inside the roasting container, it is

relatively simple to learn how to use the thermostat of the Turbo-oven's heater to create certain roast profiles.
If all the chaff is left in the bowl, it will cause some smoke formation in the roasting container and maybe some tainting of the beans if the roast is done at very high heat.
Chaff can also be diverted out through slots in the side of the bowl, which makes for quite a mess.
For a mess-free roast, one larger opening with an extraction fan can be fitted; it just depends on the skill and the enthusiasm of the home roaster!
With a proper chaff collection system this method can be used indoors.

Oven-style coffee roasting:

Basic principle: spread the green beans out on an oven tray and roast them in the oven; you will need to take them out from time to time to stir them so they get roasted evenly.

Not one of the easiest ways to roast beans, but do-able in a "no coffee-beans left!!" emergency.

"Popper" roasting:

Basic principle: small quantities of coffee beans are roasted in (sometimes modified) popcorn-poppers.

As the poppers are designed to provide a lot of heat very quickly, it is not easy to extend the roast times beyond 4-5 minutes.
You can try to extend roasting times by roasting outdoors on a cold night, increasing the airflow to the beans by cutting extra vents in the base of the popper or adding a chimney to the popper .
As the poppers are small, you generally cannot roast more than 100-130 grams at one time, and the "softer " beans, such as Brazils, may roast too quick.
Nevertheless, a great way to learn about roasting and with some experience, excellent roasts can be produced.

Small Home Coffee-roasters

As the world's interest in coffee grows, so does the market for coffee-equipment and
there is now a good range of home-coffee roasters on the market.

Gene-Cafe.

Hot air roaster; innovative angled Pyrex-glass roasting chamber which rotates to roast beans evenly.

Infinite temperature and time control, chaff collector.
I have roasted many kilograms of coffee with a Gene-Cafe and have found it to be a dependable roaster, capable of producing wonderfully richly flavoured roasts.
You can either "set and forget" a batch (350gm) or use the dials during the roast to tightly control the profile.
Placed under the range-hood or by an open window this roaster can be used indoors.

Behmor 1600

Bench-top model, rotating drum, radiant heater with catalytic converter.
The brainchild of Joe Behm, it came on the market mid 2009 and has won many supporters.
This roaster has several set profiles catering for most tastes and is capable of roasting about 500 grams in one batch.
It is virtually smokeless, chaff-less and quiet.
The Behmor's set profiles make it effortless to produce identical roasts.
Bang for your buck, and great coffee as a result!

Hot Top

Benchtop drum coffee roaster, complete with bean dump/cooler.

Some versions are programmable, some have preset profiles; all have a capacity of about 375gm.
Capable of excellent roasts; the progammable versions can be adjusted to suit specific bean varieties or one-off roast profiles.
Efficient chaff collector, several filters will keep most smoke and odour under control.
Probably one of the most advanced home coffee roasters, but also one of the most expensive.

Nesco CR-1010PR

Hot air roaster with vertical agitator.
Smallish footprint, pre-set profiles, batch size 175gm.
A catalytic converter makes for virtually smoke and odour free operation.
Great little machine, capable of good roasts.

Sonofresco Roaster

Small commercial, OR large home coffee roaster.
Hot air, gas-fired, 600gm batch (or the new 1200gm version!), roast is visible through "glass" roasting chamber, with installation of chimney (or under hood) smoke free, chaff collector.
Quality build, 9 profiles, very repeatable roasts although relatively quick.
Easy to clean and maintain, great visual attraction in shop or cafe.
Although the sound of the powerful turbine is very noticeable, it is not so loud that First and Second Crack cannot be heard.
I have used this roaster for many kilograms and found it to be problem-free and capable of producing roasts of good depth and richness in flavour.