I have only just started experimenting with roasting coffee at home. Since October last year I have roasted several dozen batches of several different varieties of green beans, using 3 distinctly different methods. Successful roasting is a lot easier than you might think – using nothing but my common sense and household items I have roasted many batches and so far I have only completely ruined one batch (because I pushed the roasting just a little too far).
Each of the methods I have used (wok, popcorn maker and heat gun) have their pros and cons, they have different variables that you can control and they each express different flavours of the beans. I have timing, volume and tasting notes as well as pictures for many of the batches that I will describe in later posts. There are also other methods I have not tried, such as oven roasting, campfires or consumer roasting machines. For now I will just summarise my experiences with the different methods I have used.
I have found that there are several variables that determine the outcome of the roast; the different methods allow you to change each of them to varying degrees. I have found the following variables to be important:
- Bean: possibly the biggest factor, different varieties of green bean react to roasting in different ways. For each new type of bean that I roast, I have tried several different roasting options before I settled on one that I thought was best.
- Heat: control over the temperature lets you control the speed of the roasting process; too hot and the outside of the bean will burn before the middle is done; too cool and the flavour in the oils will not surface.
- Time: control over how long you let the beans roast controls the “darkness” of the roast. You can stop roasting at any stage but I have found the “zone” to be after the “first crack” at a minimum and for most beans after the “second crack”.
- Amount: how many beans you’re roasting per batch changes how the heat gets to the beans. If you change the amount of beans roasted in a batch, the Heat, Time and Agitation have to be changed to get the same result. To ensure consistency of result, I use kitchen scales to make sure each batch is the same size.
- Agitation: how much you stir the beans which controls how evenly they roast and the consistency of the batch. If you don’t stir enough the beans will roast unevenly and if you stir too much then the beans won’t heat properly.
I have summarised my thoughts about the different methods and I will go in to more detail in a later article.
|Effort Required:||Constant attention|
|Roast Quantity:||20 shots (approx)|
|Effort Required:||Wait & watch|
|Roast Quantity:||4 shots (approx)|
|Convenience Factor:||Assembly required|
|Effort Required:||Constant effort (depending on setup)|
|Roast Quantity:||16 shots (approx)|
My recommendation for people who want to get into home roasting is to start off using the popcorn maker method. Don’t laugh – popcorn makers are cheap, readily available and the most convenient of the methods I have used at home. You can also only roast small batches so it doesn’t matter if you ruin a few until you get the hang of it. The heat gun method provides the best results but requires some set up effort, so I wouldn’t move to this method until you have a good feel for roasting. If you are mechanically minded then you will be able to reduce the roasting effort by rigging some automated agitation.