Over the years we have gotten used to coffee roasting and production being a huge industrial process or else done by specialist boutique-y roasters with special machines and a fancy appreciation for roasts and blending. While it is true that roasting in bulk or hitting very exact roast points does require some specialist skill and machinery, the reality is that coffee roasting really isn't too hard - probably not much more difficult than making pop corn - and the results of really fresh, fresh roasted coffee make up for any imperfection in the home roaster's skills.
A great book on the subject is "Home Coffee Roasting: Romance and Revival" by Kenneth Davids which is available from Amazon in Canada here.
Here is a quick video of me roasting a batch of coffee on my barbecue using a big iron frying pan. As usual, I am sorry for the muddy audio!
With the lid opening and closing cycles, the total process is about 10 or 12 minutes.
Note: It is important to do this outdoors! The process will generate lots of pungent blue smoke that will fill up your house in no time. Also, it works best with the really high heat from a good gas barbecue.
Tools and materials:
Here is what you will need at least the way I do it (there are lots of variations):
- Green coffee beans - these can be bought from Whole Foods in small batches to play with. For more variety and if you are in Canada I would recommend the Green Beanery . They have a very cool store in downtown Toronto and also great online ordering. Some Googling would find other suppliers too. Green beans will store in a cool place for over five years!
- A big cast iron frying pan. I believe I got mine from Canadian Tire (here). Often they are sold in the camping section. Do not use a non-stick pan! The high temperatures would ruin the Teflon coating.
- A metal colander to hold the beans after they are roasted. It must be metal! The beans will be over 500 degrees Fahrenheit when they are done.
- A long handled metal spatula for stirring the beans.
- Bowls and containers for the beans
- Very stout pot holders - I use silicon oven mitts.
- If you want to be fussy, a scale to weigh the beans out.
- A coffee grinder to process your roasted beans.
- That's about it!!
It's really pretty simple!
- Put the pan on the barbecue and get it as hot as you can! Just leave it dry with no oil or anything in it. Close the lid and let it get up to at least 500 degrees F.
- Measure out enough beans to cover the bottom of your pan. For me that's about 1/2 lb (250 gm).
- Put the beans in the skillet and make sure they are in an even layer and not bunched up. The idea is to try to roast the beans as evenly as possible.
- Close the lid and let the heat build up for a little while - maybe one minute.
- Open up the lid and stir the beans around - especially try to flip them over so the tops and bottoms get heated.
- Close the lid!
- Open it up again and stir.
- This cycle will continue for a while until you start to hear a bit of a crackling sound and see the beans start to smoke. This is called "First Crack".
- Keep opening and closing and you will see the beans pass from greenish, to yellow to light brown and then start to get darker and darker and bigger and bigger. Interestingly, the smoke doesn't really smell a thing like the "fresh roast coffee" smell we are all used to from cafes and so on - it is more pungent - like burning a piece of toast with motor oil.
- When the beans start to darken is when you need to use a bit of judgement - do you like lighter roasts or darker espresso or French roasts? Generally, when you hear an increase in crackling and see more smoke you are at "Second Crack". A this point you can leave them in a few seconds later before dumping them out if you want them to be a darker roast. Remember! The beans have so much internal heat built up, that they will roast a bit even after they are dumped out! You need to stop a bit before the final darkness of roast you want to achieve. This is really the hardest "art" of the whole roast.
- When they are ready, dump the beans out into the metal colander and stir them up to move air through them and cool them as quickly as possible. You can also give a quick spritz of water - but not too much!
- Once the beans have cooled down you can grind them and their peak flavor is actually about 24 hours after they are roasted and they will keep super fresh for up to two weeks. It is important to not store freshly roasted beans in a tightly sealed container - especially a glass one - since they will continue to out gas for a couple of days after roasting.