Sometimes it's good to check our facts. A lot of misinformation is spread about coffee. Here are a few common things people believe which are simply untrue, followed by explanations of the real facts.
1. Darker roasted coffee is 'stronger.'
First, the term 'stronger' is pretty meaningless without some sort of definition. Let's assume this means caffeine content. Roasting does not add caffeine to coffee. It is an alkaloid that exists naturally in the green bean and does not undergo any change under normal roasting conditions.
One caveat to this is that darker roasted coffee is less dense, which means that dosing by mass (when brewing) will increase the number of beans per gram. In that case, more coffee beans will be used, and therefore more caffeine will be made available in brewing. Remember, this is only a factor if you are weighing your coffee. Scooping with a spoon (measuring by volume) will not have this effect.
Another factor is solubility. Darker roasts will be more soluble due to cellular structures in the bean breaking down. This will make elements like caffeine slightly more accessible for extraction.
2. Espresso has more caffeine than filter coffee.
Again, this is one that needs some definition. When comparing ounce to ounce, espresso has much more of everything, including caffeine. However, espresso is considered a complete serving as 1 to 2 ounces, while a typical cup of filter coffee is generally 6 to 8 ounces. We must consider a serving to serving comparison. Filter coffee has roughly 125 milligrams of caffeine per serving (or more if you consume over 8 ounces), while espresso is generally closer to 100 milligrams.
This is especially fascinating, since proper espresso extraction typically requires around 50 percent more coffee per serving than filter. The main reason for this difference is the amount of time the water spends with the coffee. Brew methods that involve more time will generally extract more caffeine.
3. All regions of coffee production should be available year-round.
One of the most exciting things about our current specialty coffee culture is the awareness of seasonality. Coffee is a fruit-based product, and as such has a harvest season and a freshness-from-harvest season. Unroasted coffee will degrade over time when in storage and really has a matter of months before extreme change takes place.
It is grown in both hemispheres and so we never need go without fresh coffee, but it should be assumed that every region has its season. Granted, there are some equatorial regions (like Colombia) that have two harvests per year. But this is the exception to the rule. For more information on particular regions and their seasonality, consult your local roaster.
4. Keep your coffee in the refrigerator (or freezer) to maintain freshness.
Again, we need to explain some things. This practice was popularized because people were trying to avoid the inevitable 'staling' of coffee that might have been left in a cupboard for much too long. When enjoyed within the window of aromatic freshness, however, coffee should be left at room temperature in an airtight vessel or bag. Extreme temperature of any kind will damage your coffee's delicate aromatics, so do not put those beans in the fridge or the freezer. If your coffee is turning stale, you are buying too much at a time.
Feel confident in your coffee buying and crafting. Don't let the cloud of misinformation fog up the enjoyment of your cup. Keep brewing and drinking with knowledge.