A Guide to Roasting at Home

Posted by Ofra Ronen on 9th Nov 2019

           

Want to Roast at Home? One of the best ways you could ever hope to enjoy coffee is by roasting it yourself. When you roast coffee at home, you guarantee that every cup of coffee you make will be fresh and, with a little practice, you can ensure that it is roasted exactly to your taste.

While you can always head to your local roaster or order beans online, why not instead roast it yourself so you can begin to create superb cups of coffee from start to finish right in your own home? You will never throw away again stale beans and you will reduce significantly your beans supply cost.

In order to roast coffee at home, you’ll need a few supplies and a source of green coffee beans. It’s also important to get familiar with the process from start to finish so you can better understand how your roasting can impact the flavors of your coffee.

What Is Coffee and Why Do We Roast It?

Coffee is actually a small red cherry fruit that must go through many different stages before it reaches your cup. First, coffee is processed to remove the outer skin, pulp, and inner parchment skin. Once that is complete, the inner seed, otherwise known as the coffee bean, is dried. When it’s dried it becomes the green coffee bean that is shipped around the world for roasting. The coffee bean can be stored for long periods of time and still become fresh once it goes through the roasting process. Read here more about coffee processing. 

What Happens During the Coffee Roasting Process?

Green coffee changes drastically during the roasting process. When you roast coffee, moisture is forced out of the bean, causing it to dry and expand. During the process, some of the natural sugars are converted into CO2 gas while others are caramelized into some of the flavors that help form the complex flavors in the coffee. When the process is complete, the green bean will transform into a brown bean that is about 18% lighter while being 50 to 100% larger. As soon as the roasting process is complete, the coffee begins to “degas”, and in as little as a week or two, the roasted coffee will have already begun to lose some of its flavor and aromas.

Roasting Development

People tend to have different preferences on where they’d like to have their coffee roast fall on the various roasting stages. The most basic, common denominations that are used to separate the stages are Light, Medium, Medium-Dark, and Dark Roast. However, in Di Bartoli, we prefer to refer to the 2 distinct flavours profiles we design for the most typical brewing methods our customers use, which are Espresso Roast and Filter roast. 

At home, you can start with visuals as your guide and as your skills develop, you may want to adapt a flavour reference scale to control better nuances in the cup. 

As beans roast, their internal temperature rises. And with that rising, along with the rising of the roaster temperature, comes different considerations. Types of roasts are often differentiated by the internal temp of the beans at the time of their removal. 

Light Roast

To achieve a light roast, you are shooting for an internal temperature between 180°C- 205°C. Light roasts tend to fall around the beginning of the first crack. At this point, the bean surface is still dry, and the beans may be rather dense/hard. You would pick this type of roast if you prefer higher acidity or “brighter” brews with light body. This kind of roast is also safer to do at home, as it requires less time and a lower temperature.

Medium Roast

For medium roasts, including city and city+, you’re shooting for the 210°C-220°C window. The beans will still have a relatively dry surface but are more clearly distinguishable from the original green beans.This roast level appears around the middle to end of the first crack. Some consider anything between first and second crack to be a medium roast as well. This roast level is more popular than light roasts thanks to the more mid-level acidity and fuller body. Plus, the temperature is still manageable for most people.

Medium-Dark Roast

Medium-dark roasts reach temperatures between 225°C- 230°C. You may begin to notice patches of oil as the beans approach 2nd crack.This is the point where the roast flavors begin to feature more prominently alongside the varietal notes, creating hints of spice and a heavier body.

Dark Roast

Lastly, French Roast, Italian Roast, and Espresso Roast are all considered dark roasts. They’re roasted around 240°C. They have a decidedly oily surface and low acidity and are pulled out during the 2nd crack.This is also the point where many consider roast character to eclipse origin character when it comes to flavor. Anything beyond this point is in burnt and potential fire territory, so be extra careful if you’re going for a darker roast.

Cooling the Beans and Removing Chaff 

During the roasting process, the coffee beans will shed their outer skins, leaving behind the shell which is known as the chaff. The home roasters we recommend have their own chaff collectors so you don't need to manually remove it like more simple roasters require. 

Things You Need to Roast Your Own Coffee at Home

You will need a few supplies to get you going:

1. Home Rosters - we recommend the Gene Cafe, the Kaffelogic and the Hottop
2. Green beans - check our full range here

3. Storage - once you roast your coffee, you will need a place to store it until you use it. Remember, the more air tight the better. But even the best container won’t stop the coffee from losing its flavor and aroma after about a week if it isn’t used. Browse our storage collection here.

How to Roast Coffee 

Now that you have everything you need to roast, it is time to get started. When you roast, be sure the beans remain in constant motion so none of them become scorched. You should also be aware that the roasting process produces quite a bit of smoke, so be sure the area you are roasting is well ventilated or your house will quickly become quite smoky. Roasting coffee at home is actually a relatively easy process and it allows you to create your own custom, unique tastes in your morning cup of joy. However every roaster has its instructions and we recommend booking a short lesson with us and your new roaster to optimise its use and set you up on consistent roasting at home as quick as possible. 

While you are trying your hand at roasting, feel free to experiment using different methods and try roasting the beans for different lengths of time so you find a roast of coffee that fits with your taste preferences perfectly.

Don’t feel like roasting yourself? The next best option without leaving your house is doing a coffee subscription where beans are roasted fresh and shipped out immediately. 

Check here for all the info on how to get fresh beans landed at your door hassle free.

Happy Roasting / Drinking!