Did you know this about caffeine in coffee?
With the help of a chemical engineer who happens to work for a coffee roaster, we took a lot at the latest research around the world to answer some of the most common questions about caffeine.
What are the most common questions about caffeine?
- What is the ideal time to consume coffee?
- How much should you be drinking coffee?
- Does caffeine extract first?
- Does decaf coffee contain caffeine?
- Which as more caffeine; expresso or filtered coffee?
- Does dark roast coffee have more caffeine than others?
When is the ideal time to consume coffee?
Everyone is different and will probably have a different “perfect time” to enjoy a coffee during the day. Although, the U.S Department of Defense suggests the ideal time is between 9am and 10am. It is thought to be the best time to get the maximum impact from caffeine in terms of function and minimise the effect on sleep.
How much coffee is safe to drink a day?
An Australian group of researchers set out to measure how many cups of coffee it took to change someone’s heart rate, as this was one of the negative impacts of over-consuming caffeine. They found that it took at least 8.5 cups of espresso coffee to have any kind of effect on the heart.
Another study found that you would need to consume about 25 litres of filtered coffee to get a dramatic effect.
Does caffeine extract first?
There is an idea that caffeine extracts at a faster rate to the other compounds in coffee and effectively ‘runs out’ if the extraction is left long enough. The truth is it doesn’t. In fact, it is only possible to extract about 20% of the caffeine available in coffee. After an extraction is finished, both espresso and filter, you have about 80% of the caffeine still left inside the coffee grounds. So while running an extraction longer, does increase the amount of caffeine in the cup, you get it across the entire extraction.
Does decaf coffee contain caffeine?
Because it is hard to remove all traces of caffeine from coffee, most decaf contains between 1% and 10% of caffeine. This is a lot less caffeine than a standard coffee, it is about the same amount as found in a hot chocolate. So, it is unlikely to have any affect, unlike caffeinated coffee or even tea!
To put things into perspective; decaf coffee contains 5-10 mg of caffeine, while hot chocolate contains 5-12mg. A black coffee contains 30-80mg of caffeine and ordinary coffee contains 100-200mg of caffeine.
Does espresso or filter coffee have more caffeine?
Espresso has a higher concentration of coffee and preserve. While filter coffee such as French press and drip filter typically have more caffeine per cup.
Typically filtered coffee is drank more per cup than standard espresso. A double shot of espresso averages about 80mg of caffeine, while there is around 125mg in a filtered coffee.
The exact amount changes, depending on the quantity of ground coffee, whether the blend contains Robusta and how much water you add when brew etc. The 80mg of caffeine quoted per double shot of espresso may in fact be 100mg or 70mg. It depends on how you make it.
Does dark roast coffee have more caffeine than other types?
Some people think that because dark roasted coffee tastes stronger, it contains more caffeine. Others think that because it has been roasted darker, that some of the caffeine has been roasted off. Actually, neither of these are correct.
Caffeine is a considered a refractory molecule, meaning that it doesn’t decompose or get ‘consumed’ on exposure to high temperatures. So as far as roasted is concerned, you can not ‘roast out’ the caffeine.
In terms of dark roasts, if the origins are the same, it is identical between light, medium and dark roasted coffee. The solubility of caffeine seems to be marginally affected by the presence of other coffee compounds in there.
Dark roasted coffee tastes stronger, because it has been roasted longer and the material in that coffee is more soluble. So, it is stronger in taste, but not in caffeine.
Information within this blog was provided by our coffee partners at Seven Miles Coffee Roasters.