Roasting Coffee Beans

Roasting Coffee Beans for the Best Roast

To achieve a good roast you have to start with beans that have been skillfully selected and dried.

Some bean processors use a wash to remove the fleshy fruit from the bean and to separate different kinds of beans. Density differences in the bean will cause some to float higher, making for easier removal or separation. Others use a slower, more expensive dry-process.

Dry-processed coffee beans will have a more subtle acid profile, while the acidity of wet-processed beans is more striking. Some acidity in coffee is desirable as the alternative is a flat, lifeless cup of coffee.

What happens to coffee beans during roasting?

Roasted Coffee Beans During the coffee bean roasting process aromatics and acids, along with other flavor compounds, are produced in varying concentrations.

During the first stage the coffee beans absorb heat and the green beans are slowly dried to a yellowish tinge. Green doesn't refer to the color, per se, but simply to the beans being unroasted or raw. Properly done, the beans will have an odor reminiscent of toast or popcorn.

From about 170°C-200°C (338°F-392°F) sugars in the coffee beans will begin to caramelize, helped by the increasing temperature of the moisture enclosed in the skin.

That's just one reason it's important that your coffee beans have the proper moisture content, which comes from correct drying. Caramelized sugars are less sweet, so reaching the proper amount is important for the final roast.

At about 205°C (400°F), the coffee beans will expand to about double their original size and become light brown, simultaneously losing about 5% of their original weight.

Roasting Coffee Beans As the temperature rises to about 220°C (428°F), the coffee beans will lose about 13% more weight and release some CO2.

When the temperature increases to around 230°C (446°F), the roasting coffee beans become medium-dark brown and take on an oily sheen. Often there will be a loud pop as the beans enter the second crack phase.

At this point coffee been roasters have to be very cautious and not overdo it.

Volatile aromatic compounds are boiled off and the oils on the outside of the bean can combine with oxygen in the air. That process can strip the coffee beans of desirable flavors and lead to a burnt taste.

The goal in roasting coffee beans is to arrive at just the right balance of bitterness, acidity and a host of other attributes making up the final coffee flavor profile.

The Coffee Body

In tasting guides coffee connoisseurs will sometimes see the term 'body', as if its meaning were self-evident. Body, despite what it suggests, does NOT refer to the actual thickness or viscosity of the liquid. That attribute is the result of the kinds of proteins and fibers in the brew.

Used as tasters use it, body refers to the feel on the tongue when rubbed on the roof of the mouth. It's the result of the fat content in the drink and that, apart from growing conditions that home roasters can't control, is determined largely by roasting the coffee beans.

Too light a roast will leave too high a concentration of bitter compounds in the final product.

Too dark a roast will produce an excessive chocolatey, burnt taste.

Roasting coffee beans is about experimenting until you find a balance of flavors, body and texture that suits your personal taste.

» Tea or Coffee Cafe Home
» Roasting Coffee Beans

Tea or Coffee Home

Favorite Homemade Mocha Coffee Recipe

A Mocha Coffee Treat

Mocha Coffee - A Tasty Early Morning Treat Home made Mocha coffee is very easy to make using this recipe. You just add cocoa, sugar and milk to hot coffee and drink.