Roasting coffee beans

My daughter asked me yesterday whether I’d thought about roasting my own coffee beans. I told her no, that I thought that for whatever reason people didn’t often roast coffee beans at home, but I didn’t know why.

Today I asked an expert about this, someone who roasts and distributes coffee. He said that you can roast coffee at home, but most people don’t for these reasons.

  1. You can roast coffee in an ordinary oven, but the quality of the roast will be uneven.
  2. You can buy a machine for roasting coffee beans, but these machines are expensive and don’t roast much coffee at a time.
  3. It’s hard to find green coffee beans unless you are buying in wholesale quantities, e.g. 100 pound bags.
  4. The smell is overwhelming.

The last point surprised me. I imagined the smell of roasting coffee beans would be wonderful, but apparently it’s too much of a good thing.

Update: See the comments for different views and suggestions.

23 thoughts on “Roasting coffee beans

  1. I’m not sure the advantages would be very significant either, right? Compared with buying freshly roasted coffee from the local coffee shop that roasts their own beans.

  2. The smell is wonderful, it is very easy to source small amounts of green coffee on the internet and it is cheaper than pre-roast coffee, and air-popcorn makers roast mildly uneven great coffee(but it is true that it is only in small amounts, but the point of roasting yourself is to keep it fresh while large amounts are antithetical too anyway).

    Sweet Maria’s is a great resource, and store, for anyone getting started.

  3. Anectdotal data point – I have a friend who does roast his own coffee (outdoors!) with a heat gun and a metal mixing bowl. He buys his green beans in 5 pound bags and roasts just enough for a week or so. His coffee is delicious!

  4. I find roasting small batches of coffee at home be fun, easy, and cheap.

    Try looking for both a roaster and small quantities of green beans at An “air roaster” in the range of ~$100 will last hundreds of batches, and will produce better coffee than most people can get locally. In addition, with the cost of green beans compared to artisan roasters, it will have you saving money after just a few months, assuming you drink coffee every day.

  5. As a home roaster I can tell you that the smell isn’t necessarily overwhelming, but the process generates a ton of smoke, so you generally do it outside. It smells like burnt popcorn, but that goes away over the course of about an hour after cooling and starts to smell like plain jane coffee. And now for some reasons you should roast coffee at home:

    1. You can build a machine to roast batches of 12 oz or so at a time for about $100. Thats not too shabby. I roast 24 oz every couple of weeks.

    2. It’s cheaper than buying the beans from a local roaster. I typically pay about $5.00 a lb for green beans. You can get quantities as small as a lb from places like Sweet Marias.

    3. Green beans last longer. You can store large quantities of it (like 10lbs) for a very long time, and roast what you need. Lot’s of times you buy your coffee from a local roaster and its been sitting for more than a week.

    4. You can experiment. This is the best part. Try exotic coffees at different roast levels that you can tweak and control at home. Decide what you like, buy some more and try it roasted differently. Mix and match beans to make your own blends. Learn.

    It’s a lot of fun. I’ve been doing it for about 5-6 years now and it never gets old.

  6. My brother in law roasts his own beans. He’s had a lot of success with it. It looks like everyone else has said something similar, so I’ll just be another data point saying you can do it at home for cheap.

  7. As someone who has roasted coffee at home for over 6 years, I’ll address my thoughts on each of these points:

    1. This is a valid point. I’ve never tried roasting coffee in my oven (but have on the stove top using a cast iron skillet, but only once). I wouldn’t want to do this since there is a certain phase where they give off a lot of chaff, and eventually smoke, if you push the roast dark enough. It is important to keep the beans in motion so that they do not scorch. I can’t see getting around an uneven roast in the oven.

    2. This is also true. Most machines dedicated to roasting coffee are going to cost you over $100, and if you want to roast a pound at a time (good for a week or two), you’re probably looking at spending $500-$1000 for something like the Hot Top roaster.

    Fortunately there are other ways to roast coffee besides in your oven or in a dedicated machine. Personally, I use the “heat gun dog bowl” method. A heat gun will cost anywhere from $30 to $60, and a metal bowl, if you don’t already have on in your kitchen, only costs a few dollars. This method allows a person to roast anywhere from 1/2 pound at a time to over a pound (I usually roast between 1 and 1 1/2 pounds at a time). It is more work than using the Hot Top Roaster, so it’s not something to do unless you love quality coffee and/or like to have control over the whole process.

    3. It’s not hard to find green beans if you know where to look. I usually buy from,, and (the first two only sell green beans, the latter sells both, so make sure you are buying green). A Google search will turn up many more I’ve never even heard of, I’m sure.

    As for the cost, I made a spreadsheet after ordering coffee back in March of 2011 and calculated that I spent about $6.76 per pound on coffee, after factoring in shipping and weight loss in the beans during roasting (note: a quick glance shows coffee prices have gone up since then). Since I like to try coffee from various different regions, I usually buy several regional varieties in two pound quantities in addition to larger quantities of my favorites. If you know what kind of coffee you like and aren’t interested in getting different varieties, you can save a lot by buying in larger quantities. Since green beans can be stored for much longer than roasted, without a loss of quality, getting a lot of beans at once isn’t a big issue.

    Usually good quality coffee costs $8.00 for a 12 oz package (~$10 a pound!). If you buy your coffee in bulk, you might get a better deal, but, unlike green beans, you can only buy as much roasted coffee as you’re going to use in a few weeks, or else it will start to go stale.

    4. This is only a problem if you don’t like the smell of coffee. But then, why are you drinking coffee if you don’t like the smell? :)

    But seriously, this is a good point. You’ll probably want to roast coffee outside, because, like I mentioned in point 1 above, you’ll get chaff (some varieties more than others), and secondly because you may get some smoke, and you don’t want to set off the smoke alarms. (Like I did when I lived in an apartment once, oops!) Personally, I roast my coffee on the back deck when the weather is nice, and in the garage when it’s not (i.e. in the winter). I actually do like the smell, but it could get too pungent if done in an enclosed area.

  8. I remember the bad smell from the A&P warehouse sort of place a few blocks from us, when they roasted coffee (from when I was a kid). Now I’m a few blocks from a local coffee shop that roasts their own, and smell it when they roast – this time it’s good. Maybe A&P was burning it?

  9. I roasted for a couple of years with an air popcorn popper with louvered vents on the bottom. It was fun roasting a variety to different levels, seeing how it changed the character and developed different flavours. Even after you were done, the flavour evolved for the next few days. I leveraged the savings to try some really different green beans that I couldn’t hope to find roasted locally. Oddly, it made much better coffee than popcorn.

  10. I also have rosted my own beans in the popcorn popper method. I do not actually drink coffee, but it was something that was a lot of fun to do.

    This is one of those things that for $40 or less you can try with a popcorn maker. (See the various links above and on Google for how to do this).

    The point is not to perhaps consistently do it, but to try it. Knowing you can roast your own coffee is, to a life long learning, important in and of itself.

  11. using a behmor1600- I get most of my grren beans from burman coffee at ~5-6 dollars per pound for the lat year and I love it!


  12. In some countries, people actually roast their coffee beans in their homes and it’s not that hard.


  13. may be this is a bit unrelated, but the sentence “…too much of a good thing…” struck a chord with me. I think ‘roasting coffee beans’ is a good metaphor for the way we publish our research and apply for grants these days…..

  14. I’m sure #4 is similar to the effects of the “Wisconsin method” of cooking bratwurst (boiling in beer before grilling).

  15. My local coffee shop (where I am at this very moment) roasts their own beans every day in the front of the shop. This is one of my favorite smells, and (to me) not at all overpowering or “too much of a good thing”!

  16. When I had my coffee shop in Sihanoukvillke, Cambodia, in 2009,
    “The Khmer Gourmet”, we use to roast them in a frying pan over the stove. When they crack twice they should be done, about 10 minutes
    Green beans we purchased at the Viet Nam Market.

  17. We don’t do this much nowadays in India but when I was a youngster, we used to roast coffee in our house. The equipment was a very inexpensive one, a cylindrical drum, with an opening to pour in the seeds and a handle. You had to keep it on stand, underneath which was kept a kerosene stove. We had to manually rotate the drum using the handle and once in a while you opened the latch to check how it was done. We also had a manual grinder to grind coffee.

  18. Forgot to mention that when roasting beans in frying pan it should be medium heat and keep shaking and turning the beans so they don’t burn and untill you hear 2 cracks, about 15 – 20 minutes actually

  19. You don’t need any fancy equipment to home roast and its far easier than baking.
    I just preheat my oven to 475 f get a baking tray lined with foil, put about 3 pre roasted beans on the kitchen counter (to check my roast with) a clean metal saucepan and a metal sieve.
    Spread about 1-2 bean thick layer of green beans put it in the middle of the oven set the timer to 15 mins and read a book at about 11-12 mins I hear the first crack then I mark my page and check the beans at 12-13 mins give it a stair with a spoon and take a few beans and compare to what I have on the counter (I aim for a roast slightly lighter than what I want) keep checking every 2 mins when its done I pour it into the sieve and immediately go outside with the pot and the sieve toss the beans back and forth till its cooled and all the chaff is blown off.
    Put it in a clean airtight jar enjoy!
    The whole process takes less than 25mins and you get a glorious cup better than any you have ever drank. The roast keeps for about 6 days and the beauty is everyday the coffee taste a bit different as it matures.
    Believe me after you roast your own you are hooked for life.

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