Myth-busting: Why a longer coffee actually has more caffeine
Do you swap your after dinner espresso for a longer coffee because you don’t want to lay awake all night? Well, as much as it might seem like a strongly flavoured shot is going to pack a bigger caffeine punch, that isn’t always the case (whatever Hollywood might have told us).
Brewing methods are one of the key factors in how much caffeine is in your cup, and we’ll cover those later, but there are a few other things to consider too:
1. Where the coffee was grown
Coffee grown at lower altitudes has more caffeine, as it’s the coffee tree’s way of repelling insects. Because there are fewer insects at higher altitudes, caffeine levels in coffee grown higher up tends to be lower in caffeine. So choose coffee from countries like Ethiopia, Kenya, Colombia and Brazil for less of a caffeine hit.
2. How fine you grind your coffee
The finer the grind, the higher the surface area, and the more of the coffee’s natural caffeine and flavours will be extracted in the brew. Espresso machines usually use a fine ground coffee, which is why the flavour is so intense, but the water passes through the grounds much faster than in a drip method, where more caffeine is extracted.
3. How hot your water is
Generally the higher the temperature, the more of the natural features of the coffee will be extracted into your cup, and that includes caffeine.
4. How do different brewing methods measure up?
While you might think an espresso machine extracts the most caffeine from coffee, there can be more caffeine in a longer coffee depending on the kit you use. Plus, you’re less likely to drink a few espressos in a row, while you might go back to your Chemex a few times for a top up.
Here’s how different brewing methods measure up, from highest caffeine to lowest:
While generally the rule is the finer the grind, the higher the extraction, this isn’t the case for pour-over methods, where a fine grind would stop the water passing through. Pour-over coffee makers like Chemex use a larger grind size, but a much longer extraction time. Because the water drips through slowly, there’s more time for the caffeine to be drawn out.
This works in a similar way to a Turkish coffee pot, where the coffee grounds are immersed and dissolve. Aeropress use medium grinds to give you extraction similar to immersion methods, which results in higher caffeine levels.
Automatic drip coffee makers
A standard countertop drip coffee machine usually requires a coarser grind and operates at lower temperatures, which limits the extraction and therefore the caffeine levels. That’s why you’ll generally be able to go back for a couple of top ups without getting the jitters.
French presses need a coarser grind so the coffee can’t pass through the plunger and into your cup. So like a drip coffee maker, the finished cup tends to be lower in caffeine, especially if you don’t leave it to brew for too long.
Want to keep building your coffee knowledge? Browse our blog for more great grinding advice and brewing tips.