How To Roast Your Own Coffee

Home coffee roasting is as simple (or as technical), as you want to make it.

You can roast in your oven, re-purpose a popcorn popper, use a skillet or buy an actual coffee roasting appliance. Whatever method you use, you will be on your way to drinking much better coffee.

The basic process is simple: use heat to turn green unroasted coffee into brown roasted coffee. Roasting times vary, depending on the method and batch size, but you can expect the process to last about 10 minutes for smaller batches and about 16 minutes for larger batches.

step 1. choose a roaster

There are many ways to roast coffee. The method you choose should be influenced by how much roasted coffee you need and how much money you want to spend. Whether you choose a D.I.Y. approach or a small appliance depends mostly on if you want more or less automation.

D.I.Y methods are affordable and accessible.

We think using an electric popcorn popper is the best of the DIY methods. You can also use a skillet, a stovetop popcorn popper or a cookie sheet in your oven – while these methods are popular among home roasters, we think it requires a bit of experience to achieve good results.

Hot Air Popcorn Popper Instructions (Recommended)
Stovetop Instructions
Oven Roasting Instructions

Home Coffee Roasting appliances offer coffee specific features.

Depending on the model, machines made for home coffee roasting may offer chaff collection, smoke reduction, timers, temperature control, airflow regulation and digital automation. There is no “best” roaster per se, but there is a best one for you depending on how much coffee you want to roast per batch and how large of a machine you want to have sitting on your counter.  Air roasters are generally smaller, roast evenly without scorching, and are better for smaller batches. While drum roasters often roast more, these machines are typically larger, require more attention and generate more smoke.

See our Home Roasting FAQ for more help finding the right roaster for you.

step 2. choose green coffee
We always have a few dozen coffees to choose from so you shouldn’t have a problem finding beans that make your taste buds happy.

We suggest purchasing a Sweet Maria’s Sample Set to get started. Sample sets include 1lb bags of pre-selected coffees from the different growing regions we offer. Starting off with a sample set is an economical way to start roasting and become familiar with origin flavor characteristics. From there, your palate will have an idea of which ones are more delicious. This will help you narrow down which coffees you want to buy next.

Our Green Coffee FAQ will help take the mystery out of selecting.

step 3. the roast process

Understanding the different stages of the roast will help you control the flavor of your cup and appreciate how different roasts result in different cup flavors.

Here’s an image that provides an overview of the process:

coffee bean chart showing the degree of roast of each stage in the roast process from green to brown to black
Coffee bean chart I created many years ago showing the degree of roast of each stage in the roast process from green to brown to black. The gray stripes on either side of this image are a photographic 18% gray card. To my delight, I have found my photo here shared around the world, sometimes even with credit! I have seen it translated into many languages and edited with improvements. Cool!

  • 327 degrees F - Coffee bean macro image yellowing stage of roasting
  • 327 degrees F - Coffee bean macro image yellowing stage of roasting

Yellowing: For the first few minutes the bean remains greenish, then turns lighter yellowish and emits a grassy smell.
Steam: The beans start to steam as their internal water content dissipates. This is also known as the drying stage.

  • Just before First Crack - 393 degrees F - Coffee bean macro image browning stage of roasting
  • Just before First Crack - 393 degrees F - Coffee bean macro image browning stage of roasting

First Crack: The steam becomes fragrant. Soon you will hear the first crack, an audible cracking sound as the real roasting starts to occur: sugars begin to caramelize, bound-up water escapes, the structure of the bean breaks down and oils migrate from their little pockets outward.

  • Ending of First Crack - 426 degrees F - Coffee bean macro image during roasting
  • Ending of First Crack - 426 degrees F - Coffee bean macro image during roasting

First Roasted Stage: After the first crack, the roast can be considered complete any time according to your taste. The cracking is an audible cue, and, along with sight and smell, tells you what stage the roast is at. This is what is called a City roast.

  • Ending of First Crack - 435 degrees F - Coffee bean macro image during roasting
  • Ending of First Crack - 435 degrees F - Coffee bean macro image during roasting

Caramelization: Caramelization continues, oils migrate, and the bean expands in size as the roast becomes dark. As the roast progresses, this is a City + roast. Most of our roast recommendations stop at this point. When you are on the verge of second crack, that is a Full City roast.

  • Start of Second Crack - 444 degrees F - Coffee bean macro image during roasting
  • Start of Second Crack - 444 degrees F - Coffee bean macro image during roasting

Second Crack: At this point a second crack can be heard, often more volatile than the first. The roast character starts to eclipse the origin character of the beans at this point and is also known as a Vienna roast. A few pops into second crack is a Full City + roast. Roasting all the way through second crack may result in small pieces of bean being blown away like shrapnel!

  • Ending of Second Crack - 465 degrees F - Coffee bean macro image during roasting
  • Ending of Second Crack - 465 degrees F - Coffee bean macro image during roasting

Darkening Roast: As the roast becomes very dark, the smoke is more pungent as sugars burn completely, and the bean structure breaks down more and more. As the end of second crack approaches, you will achieve a French roast.

  • Extremely Dark - 486 degrees F - Coffee bean macro image during roasting
  • Extremely Dark - 486 degrees F - Coffee bean macro image during roasting

Ack!! Too Late!: Eventually, the sugars burn completely, and the roast will only result in a thin-bodied cup of “charcoal water.”

Check out our Use All Five Senses to Determine Roast Level and Using Sight to Determine Degree of Roast pages for more detailed information.

And for basics on the coffee aspect, see out Green Coffee FAQ

16 Responses

  1. This is a very confusing spot on your site. It would be easier to understand if it was played out as a chart. I can’t really tell what is being suggested between the Full City (City +), The Full City + (Vienna), and the French Roast. The coffee I roast become much larger during the 1st crack.

  2. Putting this here bc I dont think Sweet Maria’s has a forum for roasters. Im a newbie and could really use some help with my SR540! Im trying to capture fruit and floral notes in my beans but Im getting meh results. I usually roast to this schedule:

    minute 1-3 @ Fan 9, Heat 9
    minute 3-4 @ Fan 8, Heat 9
    minute 4-5 @ Fan 7, Heat 9 (first crack midway)
    ~cool 3 mins~

    I get mixed results, Ive never been blow away. I am lacking enough devp time? TIA!!

    1. Hey Ed – the best place to reach out for troubleshooting/roasting tips is via our email, [email protected]. I might recommend starting with a lower heat setting and ramping up to slow development time a bit. This article has some helpful theory regarding emphasizing those fruity/floral notes in your coffee. On the brewing side, I’d also try experimenting with a coarser grind and higher dose. Hope this helps!

    2. #1. Sounds somewhat like what I do, except, I turn the fan down (fan down = temp up) enough to get the roasting temp up into the 450 to 480 range and get to first crack. Once first crack is done fan back to 8 or 9 until temp drops to 400 to 425 range. Roast generally no longer than 12 min, 12 min is my basic roast time. I don’t favor anything approaching the burned/carbonized sugar taste or oily surface if I go too far. Fruity and floral are long gone if you get to this point anyway. I will dial back time on the fly if the color of the beans I am roasting get to a point I judge to be too dark or at any sign of oiliness, oiliness plays hell with my grinder. I make sure to get the fan back to 9 just before it goes into cool down mode. It seems there are lots of people that seem to think espresso beans need to be charred black and oily to make good espresso, me, not so much.

      #2 Standard batch size for me is 8oz. anything else and the above is all out the window. I am also of the opinion that if you don’t use your roasted beans in 5 to 7 days from roast they’re pretty much done after that. You will have to start chasing grind settings at 5 days and at 7 days, for me anyway, it is impossible to grind fine enough to get a 9 bar/40-45 sec pour. I use a large double basket and dose at 24 grams shooting for 48-50 grams in the cup at 40-45 seconds. Any ways if I can manage all this it produces a fairly palatable cup, to me at any rate, way the hell better than anything I’ve had anywhere in my burg. I very well could be the one out in left field here as I have no standard reference of what actually is a world class cup.

      So the take a way in all this is, don’t roast too dark and use what ever you roast in under 5-7 days, i.e. find a standard batch size and roasting profile, that lets you use what you roast in that window.

      Of course the variables go up exponentially if you start considering the bean or beans you choose to roast. I roast blends of green beans, I am told this is not ideal, probably should roast bean varietals separately then mix and grind, but for me this ends up with beans that have all to often gone past my self imposed use by date and therefore I am not able to hit my ideal pour window. Roast then mix might work for “some” high volume coffee shops/roasteries but home roasters not so much. All the (few) shops in my burg don’t or can’t meet my one absolute criteria that roasted beans absolutely must be less than 5-7 days old. None have/had a roasted on date on their products. This is the prime reason I roast my own. Even the one shop that I had a relationship with and knew when they would roast, I still ended up with beans that were dead before I could use them all up. I couldn’t drink up a pound of beans in 5 days. That business went out of business as they couldn’t or wouldn’t charge/sell at prices high enough to break even much less make a profit. They absolutely would not sell anything less than what they though was perfection even though a good proportion of their customers were likely quite unaware of what a prefect cup could be, me included. Selling into a market who’s standard of perfection is Maxwell House instant crystals is like trying to climb Mount Everest in flip flops and a thong.

    3. It’s interesting you keep the espresso fresher than 5-7 days max. I have more trouble with extraction on fresh roasts, so like to rest coffee at least 3-4 days. Maybe that’s the sweet spot for espresso when home roasting. Sounds like you have the method down to a science!

  3. So, I just did my first roast and my experience was not what I expected. Not sure I can tell the difference between first crack and second crack. To me it’s more like popping corn. first is gradual popping (cracking) followed by more cracking. So my question is, is first crack considered to be the first audible noise from the roast? I frankly would have no idea what 2nd crack is as this was not my experience. Can anyone shed more light on this for me?

    1. Hi Jason – this is a really good question and a fundamental one to to roasting. It’s hard to identify something you haven’t heard before … plus the sound of the popper obscures it. I’ve described the sound of first crack as a pop, more like popcorn. In fact it actually is the same thing happening to the popcorn kernel and the coffee bean: water internal to the bean has reached boiling point and is turning to steam / water vapor. Of course popcorn is a bit more dramatic when it hits that same point!. Second crack is different, and for me the closest sound is when you add milk to Rice Krispies. It’s a shallow sound snapping sound. The problem with some poppers is the roast process goes so fast that first crack and second crack can blur together, so you might be facing that: Initially you hear this real popping sound but it transitions without pause to a snapping sound.

      Your comment inspired me though: I made a short video today to try to document the difference in the sound of first and second crack. To get a clear recording, I roasted this batch in a skillet on a stove so there was no other sounds and the cracks were audible. I have to edit that though but just FYI I will post it this week.

  4. Cool, I look forward to seeing this. Thanks for the response and clarification. I did my second roast today, still using a cast iron skillet at this point. Hope to take a look at using an air popper in the future. I went a few minutes past the first audible crack and not into the second crack. I think the results will be better.

    1. Jason —

      You have so much joy ahead of you! People will wonder how you learned it all, and will marvel at your coffee. I started like 20 years ago with a popcorn popper and some green beans from Sweet Maria’s and burned the popper and another one out and enjoyed every step. Still learning like a novice, though. This is a good place for tips. (Also equipment — just got my first “real” roaster and it is awesome.)

      — Geoff B

  5. could you please also write up a post about flavoring your beans after roasting them? I am trying to find what flavoring product to get and how to flavor my coffee beans to get chocolate cherry flavor for instance. I’ve read that you need to “soak” them in the flavoring oil for overnight but also I’ve read contradictory articles as well. Thanks

  6. Hello,
    I am a freelance writer working on an article about grinding times for coffee beans. I am in search of a table or list of grind times for different brewing methods, along with a weight measurement of the coffee beans. Any information that you can provide on this topic would be great. If you could respond by Friday afternoon, I would be most appreciative. Your company comes highly recommended by a specialty coffee company here in Mobile, Al.
    Thank you!

    1. Thanks for your question – I don’t think we can help and I dont think i have ever seen a chart of grinding times for coffee. The only thing that comes to mind is that old “whirling blade” type grinders from companies like Krups would tell you how long to push the button the get a certain grind. I think a chart would be very grinder-specific, part of info on a retail box. But the grind time for one machine wouldnt apply to another. Anyway I hope you find your info!

  7. Thanks for this..all of this type of information helps the new guy like me; we know it’s just part of the journey but it is VERY helpful

  8. Maybe your roasting with the wrong kind of beans. try buying some Beans that have fruity and floral notes. I would Suggest Ethiopia.

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