Drinking your coffee at the corner café is fine. But to get the exact roast you want, and if you are just starting out, then you will need this ‘Ultimate guide to Home Coffee Roasting 2019’.
The editor thought that this guide would look better with the title containing the words ‘Ultimate Guide’. I thought it a bit much but as you can see the editor prevailed.
However, the rest of this story is mine, so the editor can go suck on some pens 🙂
This home coffee roasting guide is built from my personal experience of home coffee roasting for at least the past 15 years. I wouldn’t want my coffee any other way.
Some folks expressed an interest in coffee roasting, so I thought I’d share my experience to help anyone who’s interested in getting started.
If you are just starting out on your own home coffee roasting experience, then I hope that my home coffee roasting tips and techniques help you out. It is essentially a guide to home coffee roasting for beginners or a home coffee roaster Kickstarter if you like.
You certainly can sink limitless amounts of money (including your nest egg) into home coffee roasting (as you will see when you get to the coffee roasting equipment), but the impressive part is that you don’t have to when you’re just starting. Cheap home coffee roasting is how I started.
But, be wary, once you’ve gone down the rabbit hole, you might never return (the same, anyway).
Is that too dramatic? Maybe. For those who didn’t get scared away, let’s continue.
Why Home Roast Coffee Beans?
What are the benefits of home roasting coffee? What can you expect to achieve with your own home coffee roasting adventure? Let’s take a look…
What are the economics of home roasting coffee? Well, you can end up saving money, as a ‘pound’ of high-quality pre-roasted coffee is often $15+ these days, while home-roasted coffee can cost almost half of that.
I put the word pound in quotes in the previous paragraph because if you’ve noticed, a lot of coffee shops nowadays sell their beans in 12 oz. bags.
When you roast a pound of green coffee, it may only yield about 12 oz. of roasted coffee due to moisture loss that occurs as part of the roasting process.
If you’re lucky enough to have a high-quality coffee shop near you, then you can buy fresh coffee. But, if you’re getting your coffee from the supermarket, (some) mail-order places, out of a can, or a big box store, then you’re almost certainly buying coffee that has long past its prime.
In some cases, it was never prime in the first place. Not all mail-order places are bad. In particular, the coffee roasters we feature at GoodCoffePlace are known to supply freshly roasted coffee beans to your door.
The funny part is that most people have never had a decent cup of coffee, which is why many do not know the difference. And they probably never will, unless they start home coffee roasting or try it fresh from a coffee roaster.
Coffee is one of the most substantial commodity items in the world. If things haven’t changed, it’s second only to oil and petroleum.
However, there are a lot of ‘junk’ coffee beans out there. These beans are on the menu for bugs, grown in poor conditions, sitting in ships and warehouses for literally years, and are mixed with twigs (and who knows what else!).
But, there’s also high-quality coffee grown by smaller farms that take care of their crops and earn more for their efforts.
In short, the market is far more complicated than what I can post here. The point is that there is some high-quality coffee to be had if only you knew where to find it, and it still doesn’t have to break your bank.
Do you like your coffee dark (but, hopefully, not burnt), medium, or light roasted? When you’re home roasting, you get to decide.
I could list quality again as some roasters can take quality beans and turn it into a garbage roast. When roasting at home, you get to control many variables to get the roast and the quality of coffee you desire.
When you go to some coffee shops, you may find their choice of coffees with names like ‘French roast,’ ‘premium blend,’ or ‘hazelnut.’
Those labels tell you almost nothing about what you’re about to put in your mouth, but it is probably low-quality that’s covered up by burning it (most French roast).
It is not unheard of for coffee shops to use a mix of beans to mask the off-flavors (premium blend), or worse, use added flavoring (hazelnut, anyone?).
When I talk about variety, I mean you get to choose coffee bean varietals from all over the world. You may find that you prefer beans from Africa (e.g., Ethiopia, Rwanda, Burundi, and Kenya.). Maybe your preference is Central America, such as my favorite Guatemala.
Maybe, you have a preference for dry-processed, wet-processed, or a variety of other processing elements that impact the coffee flavor (even coffee processed during monsoons!).
Do you want a nutty or chocolatey flavor or a fruity or citrus flavor? Do you want something with body or something more subtle? Maybe you want a coffee with high or low acidity?
As you can see, the options are limitless when it comes to coffee. So, why settle for what someone thinks your coffee taste should be?
Do you ever run out of coffee and dread having to go to the store to get more? If you are into home coffee roasting, then you can roast as you need it.
Right now, I roast roughly every 10-15 days and roast 3 pounds per session. This takes me 45 minutes to an hour, including setup, roasting, teardown, and clean-up.
While roasting, I can do other light chores, read a book, or drink a beer for a significant part of the time. In addition to always having fresh coffee, I still have coffee when I need it.
I buy green coffee, on average, twice a year. When my stash gets low, I reorder, so I always have it available.
If you think your BBQ grill makes you popular with all of your friends, wait until they find out you home roast coffee! I frequently give freshly roasted coffee as gifts, and it’s always received with a smile!
Home roasted coffee can also be ideal gifts for your fellow home coffee roasters. They appreciate the work that goes into roasting your own coffee beans.
If you’re saying you’ve never liked coffee, that may well (always) be true. It may also be true that nothing will change that.
Coffee is not for everyone. On the other hand, I’ve met many people who have never tasted good coffee, and once they do, they find they enjoy it. Bad coffee can taste terrible.
Good coffee can taste delicious. Some people like what is arguably bad coffee and do not like objectively good coffee. I guess it is each their own?
I’m not writing this to tell you how to (or not to) enjoy your coffee. Do you like a little coffee in your cream and sugar? More power to you!
You like yesterday’s Folgers reheated in the microwave? I’m going to throw up a little bit, but that’s my problem, not yours – you be you!
If you’re going to home roast coffee, then you’re going to need a good grinder.
You can substantially improve the taste of your coffee by grinding fresh, quality whole-bean coffee with a good grinder.
What do You need to Home Roast Coffee?
Good, you’re still here! Now let us see what home coffee roasting equipment and home coffee roasting machines you need to get started.
What’s the bare minimum you need to get started with home coffee roasting? Financially, you need about $50.
You need some ‘green’ coffee beans and some equipment to roast your green coffee beans.
Your first home coffee roaster can be as simple as a skillet on the top of your stove. A common beginner home coffee roaster is a traditional hot-air popcorn popper and I will talk about that soon.
Some folks will also use a stainless-steel bowl and a cheap heat gun. There’s also a large variety of home-made and assembled roasters along with commercially built roasters for home use. I’ll talk more about roasters in a bit.
You’re probably itching to get started with the actual roast process, and I don’t blame you! However, let us first delve into what you need to start your green coffee home roasting adventure.
Most people, when they hear ‘coffee bean’ think about a dark brown to almost black and already roasted coffee bean. However, the raw, unroasted, ‘bean’ is actually a seed and is called green coffee.
What you know as a coffee bean is one of two seeds. These seeds are the ‘pit’ of the coffee cherry fruit. The seed is wrapped in parchment. The seeds in their parchment are surrounded by mucilage or pectin, which is then covered by pulp and skin.
An image I like that shows the ‘anatomy’ of the coffee cherry is in the GCP science article.
When you buy ‘green coffee’ to home roast, everything up to (and including) the parchment has been removed in various stages of processing.
I’m not going to go into the history of coffee because it is also covered in another article on GCP, but I will note that the origin of all coffee plants is Ethiopia.
What’s more important, in my opinion, is to know that there are two major species of coffee; Robusta and Arabica, with roughly a 40%/60% production split respectively.
Robusta is bitter, partly attributable to higher caffeine content, with lower acidity and sugar content.
Robusta is generally considered a lower quality bean used for instant coffees and as filler in less expensive blends. You will also find Robusta beans in espresso blends.
Arabica, on the other hand, is the bean of choice for the best tasting cup of coffee by most standards.
You are going to be roasting green coffee at home.
You can buy green coffee beans from quite a few places these days. However, I still point everyone to my favorite supplier that has never done me wrong – Sweet Maria’s.
I recommend getting their eight-pound sampler as you’ll get eight different quality coffees of varying origins. If you keep green coffee cool, dry, and out of direct sunlight, then it will remain high quality for a year or more.
If you buy green coffee from Sweet Maria’s, or other reputable green coffee suppliers, then you don’t have to worry if you’re getting properly grown beans, beans with defects, diseases, or damage.
You also don’t have to figure out if the coffee is a good varietal, from a good farm, with a good crop for the current season. You don’t have to wonder if the coffee was processed correctly, packaged, stored, and shipped.
Importantly, Sweet Maria’s, and other reputable green coffee suppliers, also demonstrate an awareness of sustainability and fair compensation and labor practices.
Other than Sweet Maria’s you can also find green coffee beans from other green coffee suppliers including Amazon.com
Green Coffee Beans – Comparison Table
Last update on 2021-03-29 / Affiliate links / Images from Amazon Product Advertising API
Many people think that roasted coffee should be very dark brown to black with an oily sheen.
One of the reasons for this is that some coffee shops depend on delivering the same product every single time while sourcing the most affordable beans they can to maximize profits.
This consistency is also achieved by the fact that the coffee always tastes the same (burnt).
In contrast, I hope to introduce you to what is possible between just minimally roasted and not quite burnt.
The general rule is that the lighter you roast, the more you will taste the individual characteristics and complexity of any given bean, and the darker you roast, the more you will taste the roast itself.
Often, the best flavor is somewhere in the middle, but every coffee bean, just like every crop, is different.
Let us now go on to some of the other factors you need to consider when roasting green coffee at home.
Coffee Roasting Equipment
There are three main types of coffee Roasters. Electric Hot Air poppers, Stovetop & Electric Pan Roasters, and Drum Roasters. Let’s have a look at examples of some of these coffee roasting machines.
Electric Hot air poppers
There are two main types: popcorn poppers adapted for coffee roasting and a dedicated hot air home coffee roasting machines.
I started out using a West Bend Poppery that you can see below. Unfortunately, this is no longer manufactured, but you can still find them on Amazon.com through third-party sellers.
Any hot-air popper with the correct design should work. The proper design has hot-air vents around a solid bottom chamber (an incorrect design has air pumped through a bottom screen).
The hot-air poppers are easy to use, produce even roasts and most should let you roast a quarter pound of green beans at a time with a roast time of just 15 minutes. The following YouTube video of a modern West Bend popper shows you how they work.
Dedicated Hot Air Coffee Roaster
These machines have heat and fan adjustments, so you can vary your roasts. They also have a glass roasting chamber for you to see what is happening during the roast and a useful chaff collector that makes clean up easy.
Some models even have connections to a computer so that you can save and then recreate your roast profiles.
Stovetop Poppers & Electric Pan Roasters
Obviously, the stovetop poppers are pans that you put on your stovetop to roast the green coffee beans.
Stovetop poppers allow you to control the temperature from the stovetop and you manually stir the green coffee beans with an inbuilt handle whilst watching the roast through a clear glass lid.
These poppers are easy to use, easy to clean and give you all the manual control you want. However, you are standing at the stove during coffee roasting and exercising one or other of your arms. Maybe it can help to keep you fit?
The electric pan-type popper automatically stirs the coffee beans during roasting, has variable temperature settings, is easy to clean, and easy to see the progress of roasting through a glass lid.
Like the stovetop coffee roasters, the electric pan-type roasters heat the coffee beans from the bottom of the pan and stirring keeps the beans moving.
You can try this electric pan-type coffee roaster.
And if you want to know how it works watch this YouTube Video!
Home coffee roaster drums use a rotisserie method to roast coffee beans in a drum made from metal mesh.
The home coffee roaster drums are usually more durable and move slowly compared with hot air roasters. They also have variable heat and time controls. This means you can design your own coffee roasting profiles..
Generally, you can complete a roast in about 20 minutes and produce up to 12 oz of roasted coffee. Some of these home coffee roaster machines look like a microwave and some look like mini commercial roasting machines!
As an aside, I’ve seen some coffee roaster drums fitted into a microwave machine. I haven’t tried these, but I’d be very suspicious of their ability to carefully regulate the temperature of the roast.
If you are really serious about roasting your own coffee, then the futuristic-looking Hottop home coffee roaster should do!
The retro-looking Kaldi Wide Coffee Bean Roaster is not too shabby either!
Then there are the stovetop or gas coffee roasting drums.
Depending on how often you make coffee, most of the suggestions above will be just fine for you. And the larger coffee roasters would be almost like have a commercial coffee roaster in your home.
In my case, I quickly got to a state where I was frequently running three poppers which kind of became work (and also would trip breakers). The larger coffee roasting machines were a bit expensive for me at the time, so I looked for something a little bit cheaper.
I’m also a kind of ‘do it yourself’ guy too, so I don’t mind trying to build stuff.
I joined a home coffee roasting community that explored lots of options for building your home roaster. Some folks created cages that ran on a rotisserie motor inside their gas grill, while others successfully modified and converted home bread machines to be roasters.
There are a few home coffee roaster forums that you could take a look at. They may give you some useful ideas.
I decided to go the SCTO (Stir-Crazy Turbo-Oven) route. This remains a very affordable and capable option that requires only minimal modification to roast a full pound of coffee beans at a time.
If you are the DIY type, then you need to be very careful of how you build your coffee roasting equipment. But if you are the DIY type you probably already know this!
If you are not the DIY type, then it is probably best for you to buy a coffee roaster to suit your style, objectives, and budget. Plus it can save you a lot of work!
What you Need to Know about Coffee Bean Roasting
Coffee roasting produces a lot of smoke. If you don’t have a good hood fan or a reliable means to exhaust outside, then you may want to do your roasting outside.
Since I moved to Texas, the temperatures stay warm enough that I can roast year-round under my carport at the front of my garage. When I lived in Missouri, I built an enclosure so I could roast in my garage and vent out a window.
Alternatively, you could get an all in one mobile chaff remover, cooler, and exhaust fan. Like the following Kaldi Chaff Collector & Cooler.
Coffee beans fresh out of the roaster are very hot. You want to cool them reasonably quickly at the end of the roast to stop the roasting process and store them.
I use a couple of cookie sheets, a small fan, a couple of colanders, and a gallon zip-lock bag. I dump the hot beans on the top cookie sheet and let the fan blow over them. This also helps blow away some of the chaff as well.
After a few minutes, I dump the beans onto the other cookie sheet and position them back in front of the fan.
After a few more minutes, I dump the beans into one of the colanders, point the fan up, and dump the beans back and forth between the two colanders. This takes a few minutes, but it allows them to finish cooling and blows away most of the remaining chaff.
Alternatively, you could use the Kaldi Chaff Collector and Cooler mentioned above.
BROOM AND DUSTPAN (OR SHOP-VAC)
As you roast the coffee beans, they will slough off a very fine brown skin called chaff.
It’s a lighter color and a little more delicate than the husks you find in bran, but similar to the skin of a Spanish peanut.
The point is, it will spread everywhere, which makes cleaning a hassle, but not a deal-breaker. You’ll also get chaff all over the place during the cooling process, so be prepared to mop up.
How to store home roasted coffee? Well, you can use something as simple as a craft paper bag, a Ziploc bag, a mason jar, a standard canister, or something more purpose suited such as bags or canisters with one-way valves.
I use the Ziploc to transfer the beans from the colander to my storage canister because it’s hard to pour them directly from the colander into the canister.
That’s it! If you have a roaster and those few accessories, then you’re good to go.
Thank you for hanging with me this far. Now, let’s move on the home coffee roasting method.
Home Coffee Roasting Method
Now that you’re well informed about coffee beans, you’ve ordered and received your green coffee, you’ve dug out an old hot-air popcorn popper you’ve meant to put in the garage sale for the past ten years, and you’re ready to start roasting. Excellent – let’s do this!
Here is the basic home coffee roasting method:
- Setup and turn on popper
- Add 4oz of green beans
- Wait for coffee to roast
- Dump and cool
Wasn’t that easy? OK, fine, I’ll go into more detail. However, it is almost that easy. (Now you know why I had to write so much before getting to his point).
Details of Home Coffee Roasting
What To Expect
A green coffee bean is very dense, smaller than when roasted, smells ‘grassy,’ and has got approximately 10-12% water content. The color can typically be dull light green, a slightly bluish-green, or grey-green.
Some visually observable physical changes will occur during the roast process. The three most apparent will be a change in color, a change in size, and the sloughing off of the silverskin more commonly referred to as the chaff.
While these visual indicators are undoubtedly useful and important, there are also audible and aromatic indicators that you will want to become familiar with to determine the roast progress and level.
The visual indicators are not 100% reliable by themselves, so it’s essential to become familiar with the other indicators (in my experience, some of my roasts look darker than what the other indicators tell me was achieved with the roasting).
As the bean heats up, it will first start to lose moisture. The roasted bean will only have about a 2.5% moisture content and will lose up to 20% of its weight.
Coffee beans have strong cellular walls. As the roasting process progresses, physical and chemical reactions take place, which will cause an audible ‘crack’ as the cell walls of the cell walls begin to break down, the bean expands and becomes more porous.
The completion of the “1st Crack” is generally accepted as the minimum roast level and is often referred to as a ‘City Roast’ level. The 1st Crack is audibly similar to hearing popcorn pop, though not as loud and not as violent.
The coffee bean, leading up to the 1st Crack, will expand a little and the color will tend to turn to more of a yellow and then a mottled yellow-brown.
The chaff will be visible on the beans and begin to slough off (but not heavily). The smell will progress from grassy to hay-like, to something of toasted grain.
As the heat is applied the bean will reach “2nd Crack”. The sound at this point can be very faint and is more akin to the sound of those rice breakfast cereals. This is often difficult to hear over the sound of the roaster.
Between City Roast (the end of 1st Crack) and 2nd Crack, the roast level will progress through City+, Full City (just before 2nd Crack), and Full City+ in the middle of 2nd Crack.
The beans at this point will have expanded (sometimes considerably) and will have taken on progressively darker and more consistent shades of brown. You will be able to smell the caramelization of the sugars in the beans.
If you continue to roast the beans at this point, then you will progress through Vienna/Light French, Full French, and charcoal.
You will notice the smell will become far more pungent. If these roasts are your thing, then I will continue with my mantra of drink what you enjoy. That said, if you’ve never tried lighter roasts, I urge you to consider giving them a try.
The first time you try a light roast, it could create cognitive confusion which is why I suggest trying it more than once. It’s not exactly an acquired taste, but it can take time to adjust expectations and accept it as appropriate.
There is quite a bit more to judging the degree, or phase, of your coffee bean roasting.
The following YouTube video, by Sweet Maria’s, shows how you use sight to determine the degree of coffee bean roasting.
Your First Roast
OK! You are ready to give your first roast a try with a hot-air popper.
As a general rule, you want to use about 4 oz. of green coffee. If you don’t have a scale or that isn’t working out for you, then add green coffee in small amounts until it just barely stops moving around. That is the max load.
As the coffee heats up and loses some weight, it will begin moving around again. If the coffee never moves around, you’re going to get a very uneven roast with some beans burned and others not even roasted, so the movement is essential.
There are a couple of common causes if you don’t get any movement of the beans in the popper. The most common is that you’ve overloaded the popper and should try again with fewer beans.
If you’ve started a roast and you’re starting to worry about it not moving, use a wooden spoon to remove some of the beans. The other possibility is that your popper isn’t putting out enough heat, airpower, or both.
If you have your popper connected to the mains with an extension cord, then it may be responsible for the lack of power. Remove the extension cord and try again.
Conversely, if you feel like you are roasting too quickly, then you can use an extension cord to reduce the power and thus the roast speed.
You’ll want to store your freshly roasted coffee beans in a container that has a way for carbon dioxide to escape.
If you’re using a canister or bag with a one-way valve specifically for this purpose, then seal it up and gently squeeze the bag to remove all of the trapped air. If you’re using a mason jar, then don’t seal it completely tight, but do put the lid on it.
You can brew the coffee immediately after roasting, and it should be quite pleasant. However, it wouldn’t have had a chance to de-gas and to hit its prime which can take anywhere between a day to 5 days, and sometimes, maybe more.
The type of roaster used, the actual roasting process (e.g., time, temperature profile, and cooling), the roast level, how it’s stored, and the green coffee bean itself can all impact when the bean hist its peak flavor.
You will need to follow the process of trial and error until you reach that sweet spot.
Is that it? Are we done? Almost.
You may want to know about some of the home coffee roasting accessories that could make your job a little easier or harder (depending upon how much detail you want).
HOME COFFEE ROASTING ACCESSORIES
The coffee roasting accessories you need depends on your choice of coffee roasting method and the equipment you use.
However, the five accessories likely to be useful for most cases are a digital balance, a digital timer, a thermometer, a book about home coffee roasting, and a logbook.
A digital balance is useful for consistent measurement of your green coffee beans into your home coffee roaster and for measuring your ground coffee for your particular brewing method.
A timer can help you keep track of each step of your roasting method and allow you to reproduce the exact same roast profile later (provided you keep a logbook!).
Some of the coffee balances mentioned above also have timers, but a separate timer is handy to have next to your roaster.
A thermometer will help you determine when the 1st Crack and the 2nd Crack is about to be reached by simply watching the temperature rise during coffee roasting. It gives you that ‘edge’ to help you get ready and know where you are in the roasting process.
The thermometers that are useful for home coffee roasting include the good ol’ thermocouple, a digital thermometer, and infra-red thermometer.
If you are a bit of geek and crave for analysis, then you may like that some of the digital thermometers also include a data logger. The thermometer plus data logger plugs into the USB port of your computer where you can analyze your roast’s data to your heart’s content.
See some best selling thermometers that should fit your needs.
Home Coffee Roasting Books & Logbook
There is only so much I can cover in an ‘Ulitmate guide’ to home coffee roasting. There is certainly enough here to get you started.
However, if you crave for more details then you can’t go wrong if you bought a couple of good books on home coffee roasting.
The book by Kenneth Davids – Home Coffee Roasting: Romance & Revival is often quoted as being one of the best books to read. As Kenneth Davids says “If you can read you can roast!” (Subtitle of Chapter 1)
The editor liked the following paragraph from the first chapter because it suited this article:
“…anyone who can read this book can produce a decent to stunningly superb roast at home. Jabez Burns, probably the single greatest roasting innovator in American history, once said that some of the best coffee he had ever tasted was done in a home corn popper.”
The book was first published in 2003, but it is still a mine of information including the history of coffee roasting.
If you want to reproduce your great roasted coffee, then you will need to keep records. A written record is easy and you can write as you roast. You can keep records in just a normal diary, a notebook, or a dedicated roaster notebook.
You also have the option of using your computer to record and analyze your roasting data especially if you use a data logger that I previously mentioned.
Are We Done Now?
Yes, we are done for now.
Thanks for sticking with me all this time!
I hope you enjoyed the article and that it was useful for you.
Please leave a comment and let me know if there’s something you were hoping I’d cover. I’ll add it to the list and hopefully write another post.
Meanwhile, happy home coffee roasting!
Good Coffee Place (GCP), and the author, does not receive any compensation (money or other rewards) by recommending Sweet Maria’s green coffee. It just happens to be a good supplier of green coffee beans.
If you know of an equally good supplier of green coffee beans, then please let us know. We would love to feature them on goodcoffeeplace.com