What are decaffeinated coffee beans?

A Little Guide to Roast Decaffeinated Coffee Beans

Decaffeinated coffee beans, I hear you say?

Why should I start with decaffeinated coffee beans?

Why not let the roaster grind decaffeinated coffee beans instead and send me ground decaf coffee?

Well, this little guide will demonstrate why you should always use and grind decaffeinated coffee beans - instead of brewing decaffeinated coffee using ground coffee.

What are decaffeinated coffee beans?

Decaffeination is the act of removing caffeine from coffee beans, cocoa, tea leaves and other caffeine-containing materials. This fancy explanation simply means that the caffeine has been removed from the coffee beans - resulting in decaffeinated coffee beans.

What kind of decaffeination processes are used on decaffeinated coffee beans?

There are many ways to create decaffeinated coffee beans including the Swiss Water Decaf Process, the CO2 Decaf Process, the Methylene Chloride Decaf Process and the Ethyl Acetate Decaf Process (EA)

Here's a quick run through the various processes to manufacture decaffeinated coffee beans:

Swiss Water Process Decaffeinated Coffee Beans

Decadent Decaf only uses Swiss Water Process decaffeinated coffee beans, which are certified 99.9% caffeine free and uses water (no yukky chemicals whatsoever) to decaffeinate the beans.

Developed in Switzerland in the 1980s, the Swiss Water Process is a chemical free process. The green (raw) coffee beans are immersed in water to extract the caffeine using water saturated with desirable coffee components, thereby reducing the extraction of coffee oils and flavours during the decaffeination process.

This means the caffeine is extracted, but not the flavour. This steaming process takes 8 to 10 hours and involves moving the decaf batch into various baths of steam. Currently, Decadent Decaf only uses premium, high-grade coffee beans decaffeinated using the Swiss Water Process. 

CO2 Decaf Process Decaffeinated Coffee Beans

The CO2 method was developed by Dr. Kurt Zosel of the Max Planck Institute.

In science-speak, this is called supercritical fluid extraction. Basically, the process starts with the beans being immersed in carbon dioxide (same gas as in sparkling water) for around 10 hours.

Some roasters call it the Sparkling Water Decaf Process, but we think that this is not accurate  and they should use the correct term CO2 Process.

After a thorough soaking, the pressurized CO2 containing dissolved caffeine is removed from the chamber which is returned to atmospheric pressure, allowing the CO2 to evaporate.

This allows the caffeine to be removed using charcoal filters. Again, this process avoids the use of any harmful substances and Decadent Decaf is investigating sourcing premium, great tasting beans using the CO2 Process for the future.

In environmental terms, the CO2 used is in a permanent cycle, rather than vented to atmosphere – there will be some further off-gassing when the beans are removed from the system (no process being perfect), but for the most part, it’s a closed system, which is good news for the environment.

Methylene Chloride Decaf Process Decaffeinated Coffee Beans

Methylene Chloride solvent decaffeination is the old fashioned way to decaffeinate coffee and it's still how the vast majority of coffee is decaffeinated globally.

When you drink decaffeinated instant coffee, it will almost certainly be decaffeinated using the Methylene Chloride solvent process. Likewise, if there's no mention of how the roast coffee was decaffeinated on the packet, again, it's almost certain to be MCP.

But what is it? Methylene Chloride is a colourless chemical solvent in liquid form with a slightly sweet aroma with a  a boiling point of 104°F. It is a chemical solvent with multiple uses including paint remover and hair spray.

Ethyl Acetate Decaf Process Decaffeinated Coffee Beans

An increasingly popular newish decaffeination process is the Ethyl Acetate (EA) decaf process, often called "Sugar Cane Decaf", but what is the EA decaf coffee process all about?

Simply put, the Ethyl Acetate decaf method uses a natural solvent  - Ethyl Acetate - to decaffeinate the coffee beans.

Ethyl acetate is seen by some to be more “natural” than other chemicals since it exists naturally  in minute quantities in ripening vegetation, such as sugar cane, apples and blackberries.

Therefore, since this solvent occurs in nature, it's often marketed as “naturally” decaffeinated or as "Sugar Cane Decaf" since Ethyl Acetate is usually sourced as a by-product from the fermentation of sugar cane during the manufacture of processed sugar.

But, according to various scientific sources (source: Coffee Confidential), because of the cost of gathering natural ethyl acetate, the chemical used for decaffeination is often actually synthetic.

This is because Ethyl acetate can be more affordably sourced and manufactured using ethyl alcohol and acetic acid, both of which are normally produced from natural ingredients and petroleum derivatives.

Why should you drink coffee using decaffeinated coffee beans?

There are 2 main reason to brew coffee using decaffeinated coffee beans:

a) Freshness - by grinding coffee as you need in a "Just In Time" way, you can maintain optimum freshness and flavour. Buying a coffee grinder is really the best thing you can do to improve your coffee experience. Seriously.

b) Choosing your grind - each brew method such as espresso, cafetiere, V60, Aeropress, filter, stovepot - require a different optimum coffee grind, so it's best to grind decaffeinated coffee beans using the correct grind setting. This is also a vital factor for brewing great coffee from decaffeinated coffee beans.