One of the questions we're asked most frequently at Swiss Water is "How much caffeine is in a cup of decaf?" Most people know that even decaffeinated coffee is not 100% caffeine free. Due to the nature of decaf processing—any kind of decaf processing—it's just not possible to get every single molecule of caffeine out of a coffee bean (unless you remove the flavors that make coffee taste like coffee). But what does this mean in real-world terms if you're trying to avoid caffeine for health reasons, or limit caffeine for any reason—and want to know how much you're taking in?
The answer is a hard one to give. In truth, there are so many variables (like the method of brewing or amount of coffee used) involved in bringing a decaf coffee from us to you that the precise amount of caffeine in your final cup is literally always going to vary. We’re aware of a range of results across different peer-reviewed studies, as well. A 2006 study from the University of Florida College of Medicine in Gainesville found caffeine content in a cup of brewed decaf landed somewhere between 3-15mg, depending on size of coffee and method (shot of espresso or 16oz brewed). On average, we find that a cup of decaf has about 10% of the caffeine of a regular coffee—which works out to a little less caffeine than you’d find in an ounce of dark chocolate, or less than half the amount of caffeine in a can of Coke.
Why is it so difficult to give hard numbers on how much caffeine is in decaf coffee? There are a few reasons. While we guarantee that any decaffeinated green (unroasted) coffee that comes out of the Swiss Water is 99.9% caffeine free—how much of that 0.1% ends up being consumed can vary. The Swiss Water® Process is only one stage in a coffee's journey. After it leaves our hands, coffee goes to the roaster, where how a coffee is roasted can affect remaining caffeine levels. Unfortunately—the effects of roasting on are consistently inconsistent, according to both our research and that of others. Which is to say that we can't know for sure how much caffeine levels will be reduced by any particular style of roasting, be it light or super-dark—though the process rarely has a huge impact on caffeine content.
Once a decaf coffee is roasted, there's also the matter of brewing it. How a coffee is brewed in a café or home environment can determine how much of that small amount of left over caffeine makes it into your cup: obviously, if you brew your coffee extra-strong and use a lot more coffee in the process than someone else does using the same type of coffee and brew method, you would have a little more caffeine in your cup than that person. These variables affect how much of that trace caffeine may linger, and this can vary by a few milligrams per cup. If caffeine sensitivity is an issue for you, we recommend trying a variety of beans and brewing methods to see which decaf feels best for your body and your lifestyle.
We know it's frustrating to not have a specific answer that fits all people and all situations, but at the end of the day, caffeine comfort and safety is going to be a personal decision for each individual, and for those with health concerns regarding caffeine, we always recommend consulting with a medical doctor. If you opt to drink decaf, starting with a process that results in 99.9% caffeine free coffee, and does so without adding any chemical solvents like the Swiss Water® Process, is the best way to set yourself up for success. Cheers!
