Heard rumours that your cup of decaf coffee may contain chemicals? Read on to find out more.
Love your morning coffee or tea, but want to cut down on caffeine? Then decaffeinated varieties might seem like the perfect choice – especially if you regularly experience negative side effects after consuming caffeine, such as insomnia or feelings of anxiety.
But just how is caffeine extracted from your favourite hot beverages? And is decaf coffee or tea bad for you?
We spoke with registered dietitian, Jasmine Carbon, to find out more about the decaffeination process, plus the effects on your health if you opt for decaf.
What is decaf coffee and tea, and how is it made?
‘Put simply, decaffeination is the removal of the caffeine (a chemical compound) found in coffee beans and tea leaves,’ explains Carbon.
For a cup of tea or coffee to be classed as ‘decaffeinated’, at least 97 per cent of the caffeine must have been removed, meaning there will likely still be a small amount of caffeine in your drink.
But how is it made?
‘There are many ways for caffeine to be extracted,’ reveals Carbon. ‘Some use chemicals as solvents, while others use heat, water and high pressure.’
‘Chemical solvents, such as dichloromethane (also known as methylene chloride) or ethyl acetate, are used to draw caffeine from coffee beans,’ says Carbon. ‘The unroasted (green) beans are first steamed and then rinsed with the solvent, which extracts the caffeine, while leaving other molecules that give the coffee its taste and nutritional profile largely unaffected. The process is repeated from eight to 12 times, until the caffeine content meets the required standard.’
‘An example of a non-chemical method is called the Triglyceride Method,’ says Carbon. ‘To draw the caffeine to the surface of the beans, green coffee beans are soaked in hot water. The beans are then transferred to another container, and immersed and soaked in coffee oils that were obtained from spent coffee grounds. This is left to sit for several hours at a high temperature, allowing a fatty compound within the oils called triglycerides to remove the caffeine, but not the flavour elements, from the beans.
‘Other non-chemical methods of extracting caffeine include The Swiss Water method, which uses water, high pressure and activated charcoal filter to remove the caffeine molecules.
‘Tea leaves are decaffeinated by a process that involves using carbon dioxide (a natural gas), high pressure and water.’
What should you consider?
While all methods of decaffeination are now deemed safe, you may prefer to opt for an organic version, which will use a non-chemical decaffeination method.
‘Some people prefer the idea of the charcoal filter or CO2 method, because they avoid the chemical solvents, but there’s no evidence that one method is safer than another,’ says Carbon.
Unfortunately, it’s sometimes hard to determine which method is used.
‘Some producers choose to label their decaf coffee with the method used to make it, but there’s no legal requirement for them to do so,’ says Carbon
How much caffeine is in decaf coffee and tea?
Decaf coffee and tea still contains some caffeine.
The amount of caffeine in decaf coffee and tea will vary depending on how it is made.
However, on average:
- a cup of coffee will contain between 80 to 100mg of caffeine
- a cup of decaf coffee will contain between 2mg and 15mg of caffeine
- a cup of black tea will contain around 48mg of caffeine
- a cup of green tea will contain around 28mg of caffeine
- a cup of decaf black tea will contain around 1mg of caffeine.
Is decaf coffee and tea bad for health?
‘Before dichloromethane or ethyl acetate were used as a solvent, the most common solvent used to remove caffeine was benzene, which is recognised today as a carcinogen,’ says Carbon. ‘Luckily, we don’t need to worry about consuming this from our decaffeinated drinks anymore.’
But what about the safety of the chemical solvents used now?
A quick Google search of dichloromethane reveals that, as well as being used in the removal of caffeine from tea and coffee, it’s also widely used as a paint stripper, which is probably why chemically decaffeinated tea and coffee still courts a certain level of controversy.
Dichloromethane has been shown to cause coughing, wheezing, shortness of breath, headaches, nausea and vomiting if inhaled directly – but the trace amounts found in decaf tea and coffee are apparently so minuscule, they won’t negatively affect your health.
‘Consumers of coffee decaffeinated by chemical solvents don’t need to worry about the decaf coffee residues in the cup,’ reassures Carbon. ‘The level of solvent remaining after the process is over is extremely low, and below the level deemed safe by European regulations.’
And if you’re worried about the effect on the environment of chemical decaffeination, again Carbon says you can rest assured no major harm is being done.
‘Since progressing to large-scale coffee roasting, the coffee industry has developed ways of recycling the solvents used to produce decaffeinated coffee,’ she says. ‘The cycle can be repeated hundreds of times, without significant or detrimental atmospheric contamination.’
Health benefits of decaf coffee and tea
The next question is whether decaf tea and coffee is good for you? While coffee often gets a bad rep, it actually contains beneficial antioxidants. In fact, one study of more than 521,000 participants found that both male and female coffee drinkers had a reduced risk of dying than non-coffee drinkers. So do these benefits remain the same in decaf versions?
‘The decaffeination process only alters the level of caffeine within the bean or tea leaves, so all the antioxidant properties remain,’ reassures Carbon. ‘Antioxidants are great, because they remove potentially harmful free radicals from the body. Decaffeinated coffee and tea also provides some vital minerals to the diet. One study found that one cup of brewed decaf coffee provided 2.4 per cent of the recommended daily intake of magnesium, 4.8 per cent of potassium, and 2.5 per cent of niacin (vitamin B3).’
Naturally decaf options
When it comes to hot drinks, your options don’t boil down to simply chemically or non-chemically decaffeinated tea or coffee. There are a whole range of naturally decaf drinks out there.
‘Herbal teas, which are leaf or fruit based, are great naturally caffeine free alternatives to decaf or caffeinated drinks, says Carbon. ‘Great alternatives include peppermint (research suggests that it’s effective in reliving irritable bowel symptoms), chamomile or lavender (both having soothing and calming properties), or echinacea tea (some research suggests it can help to relieve cold/flu-like symptoms).’