DECAFFEINATION

Caffeine occurs naturally in plants.

Not only coffee, but also cocoa, tea and many other plants in natural contain caffeine. It provides 2 benefits to the plant. One, caffeine inhibits the growth of other plants (reducing competition) and two, the bitter tasting compound is found in the tree, leaves, fruit and seed of plants to protect them from attack by disease or pests. After all, if you had the choice between a sweet plant and a bitter one - you'd select the sweet tasting plant. So goes nature.

For thousands of years, caffeine has been a popular drug. Today it is globally the most widely consumed psychoactive stimulant with many positive uses and some abuses.

Caffeine was first isolated and extracted over 200 years ago by Friedrich Runge in 1820. Later, in 1905 caffeine was first extracted for commercial coffee use by Ludwig Roselius who accidentally discovered that a container of coffee dropped in sea water, when restored, lacked much of its original caffeine content. Thus the process of hydrating and expanding the coffee beans to extract caffeine was born.

~ C8H10N4O2 ~

The caffeine molecule can be understood chemically as C8H10N4O2. No you do not need to memorize the chemical structure for an exam : ) Caffeine is odorless and is dried as a white powder with an intense bitter taste.

Noted above the 2 common chemical solvents used for decaffeination are Ethyl acetate and Methylene Chloride (Dichloromethane). For some time Benzene was used, but it was later discovered that Benzene is a carcinogenic (contributing to cancer). The 2 chemical free options for decaffeination use carbon dioxide or water to extract caffeine.

ONCE DECAFFEINATED, COFFEE CHANGES!

• "Green" coloration changes to a muted purple/brown.
• When roasted color will appear darker than it would if not decaffeinated.
• All flavors change, may be lost and are muted. No, it will not taste the same after decaffeination.
• Decaf coffee will be much less bitter, especially when light roasted. Caffeine tastes bitter after all.
• Decaf coffee should roast much easier with reduced density and smooth roast curves with soft or imperceptible cracking sounds.

2 SYSTEMS - 2 DECAF STANDARDS

• In the E.U. coffee must be 99.9% caffeine free. The focus here is % FREE from original amount. Of the 100% coffee (grounds, fibers, everything) only 0.1% can be caffeine in order to qualify as "decaf". If an average Arabica coffee contains 1.2% caffeine (it is already 98.8% caffeiene free) then the maximum allowed to remain in the EU is 0.1%.

EU: 100% - 99.9% = 0.1%

• In the USA coffee must have 97% caffeine removed. The focus here is REMOVAL from original amount. Of the 100% caffeine present in a robusta coffee (est. 2.4%) we must remove at least 97% of that 2.4% to qualify as "decaf" in the USA. With the 2.4% Robusta caffeine let's find 100% - 97% = 3% of that original 2.4%.

USA: 3% * 2.4% = 0.072%

(hint: 0.03 * 0.024 = 0.072)

Don't worry if this is a bit confusing. Like switching from Metric to US Imperial Standards you can quickly train your mind to think in terms of "what % of this coffee IS caffeine (EU)" and "how much of the caffeine has been removed or remains (US)?"

Great work!

Get ready for your Mock-SCA Green Coffee exam.