Coffee is one of the most popular drinks in the world, and its high caffeine levels are one of the main reasons why. It’s a natural stimulant that provides a boost of energy, and we can’t get enough of it.
However, some people prefer to limit their caffeine intake for health or other reasons. Decaffeinated or “decaffeinated” coffee is widely available and its consumption is reportedly increasing.
Here’s what you need to know about decaffeinated coffee: how it’s made, its flavor, its benefits, and whether it’s actually caffeine-free.
How is decaf made?
Eliminating caffeine while preserving the aroma and flavor of a coffee bean is no simple task. Decaffeinated coffee is made by ridding unroasted green coffee beans of their caffeine content and relies on the caffeine dissolving in water.
Three main methods are used to remove caffeine: chemical solvents, liquid carbon dioxide (CO₂), or clean water with special filters.
The additional steps required in all of these processing methods are why decaffeinated coffee is often more expensive.
Solvent-based methods
Most decaffeinated coffee is prepared using solvent-based methods because it is the least expensive process. This method is divided into two other types: direct and indirect.
The direct method involves steaming the coffee beans, then repeatedly dipping them in a chemical solvent (usually methylene chloride or ethyl acetate) which binds to the caffeine and extracts it seeds.
After a predetermined time, the caffeine has been extracted and the coffee beans are steamed again to remove any residual chemical solvent.
Is matcha good or not matcha?
The indirect method still uses a chemical solvent, but it does not come into direct contact with the coffee beans. Instead, the beans are soaked in hot water, then the water is separated from the beans and treated with the chemical solvent.
Caffeine binds to the solvent in water and evaporates. The caffeine-free water is then returned to the beans to reabsorb the flavors and aromas of the coffee.
The chemical solvents (particularly methylene chloride) used in these processes are a source of controversy surrounding decaffeinated coffee. Indeed, methylene chloride is slightly carcinogenic in high doses. Methylene chloride and ethyl acetate are commonly used in paint strippers, nail polish removers, and degreasers.
However, the Australian and New Zealand Food Standards Code and the United States Food and Drug Administration permit the use of these solvents to process decaf. They also place strict limits on the amount of chemicals that can still be present on the beans, and in reality there are virtually no solvents left.
Solvent-free methods
Solvent-free methods that use liquid carbon dioxide or water are becoming increasingly popular because they do not involve chemical solvents.
In the CO₂ method, liquid carbon dioxide is pumped into a high-pressure chamber with the beans, where it binds with caffeine and is then removed under high pressure, leaving the decaffeinated beans behind.
The water method (also known as the Swiss water process) is exactly what it sounds like: it involves extracting caffeine from coffee beans using water. There are variations of this method, but the basic steps are as follows.
For a first batch, green coffee beans are steeped in hot water, creating an extract rich in caffeine and aromatic compounds (the unflavored beans are then discarded). This green coffee extract passes through activated carbon filters, which trap caffeine molecules while allowing aromas to pass through.
Once created in this way, the caffeine-free extract can be used to steep a new batch of green coffee beans – since the flavors already saturate the extract, the only thing that will be dissolved from the beans is the caffeine.
Is caffeine completely eliminated from decaf?
Switching to decaf may not be as caffeine-free as you think.
It is unlikely that 100 percent of the caffeine will be removed from coffee beans. Just as the caffeine content of coffee can vary, small amounts of caffeine are always present in decaf.
However, the amount is quite modest. You would need to drink more than ten cups of decaf to reach the level of caffeine typically found in a cup of caffeinated coffee.
Australia does not require roasters or producers to detail the process used to create their decaffeinated coffee. However, you might find this information on some producers’ websites if they have chosen to advertise it.
Does decaffeinated coffee taste different?
Some people say decaf tastes different. Depending on how the beans are decaffeinated, certain flavor elements may be co-extracted with the caffeine during the process.
Caffeine also contributes to the bitterness of coffee, so when the caffeine is removed, some of the bitterness disappears as well.
Do caffeinated and decaffeinated coffee have the same health benefits?
The health benefits of drinking decaffeinated coffee are similar to those of caffeinated coffee, including a lower risk of type 2 diabetes, certain cancers, and overall mortality. More recently, coffee has been linked to better weight management over time.
Most health benefits have been shown by drinking three cups of decaf per day.
Moderation is key, and remember that the greatest health benefits will come from a balanced diet.
Lauren Ball is Professor of Community Health and Wellbeing at the University of Queensland. Emily Burch is a dietitian, researcher and lecturer at Southern Cross University. This piece first appeared on The conversation.
