What’s your strongest coffee?
We are asked this a lot and have finally got around to writing an answer. Here’s the bad news though, this is a question that you can really only answer yourself, but if that is too abstract here’s the short answer.
Short answer – the word strength means different things to different people and the description we use is probably not one of those. Simply try a few different coffees brewed in different ways or using different coffee to water ratios and see which you prefer, espresso is a good starting point but annoyingly is the most complex and tricky to get right.
If you’d like a more detailed and nuanced answer here we go. First things first, when discussing anything in a scientific way we must define terms and this is a headache because strength can have several meanings. We will go through a few of them and then explain how the coffee industry defines it and lastly give a few ideas on where to go next.
1. Caffeine. This is pretty straightforward, robusta beans have about twice the caffeine of arabica beans but also tend to be more bitter and with fewer desirable flavours which is why we don’t use it – all our coffee is arabica. Next factor is the degree of roast, as you roast coffee the caffeine is gradually being burnt off and going up the chimney so a darker roast profile will have less caffeine.
2. Bitterness. A common perception is that more bitter coffee is stronger and if this is what you’re after the way to achieve it is to brew your coffee for longer. Without going into detail the bitter compounds tend to extract towards the end of the viable brewing window so if you push that a bit further then your coffee will have that bitterness.
3. Roast. Supermarket coffee with “strength levels” are to blame for this one, usually a scale of 1 to 5 indicating the darkness of the roast but labelled as strength. Obviously if you’re after caffeine this is the wrong way round as described above but correct if bitterness is your aim.
The coffee industry defines strength as a percentage of the brew that is dissolved coffee and a typical target for well extracted coffee is around the 18%-22% mark. This is measured with a refractometer calibrated for coffee and described as total dissolved solids or TDS. We would describe a coffee around this range as having aspects of a tasty balanced brew which is; clean cup with no unwanted flavours or residue, balanced with a harmony between acidity, bitterness, and sweetness and finally, complexity having many flavours and aromas.
To achieve this we use the SCA gold standard of coffee which is 50g-60g of coffee to 1 litre of water. (not including espresso). To play around with strength you can play around with coffee to water ratios to find what works best for you. At this point a good analogy is a gin and tonic, if you make a slightly weak one, the solution for the next round is to put more gin in rather than go out and buy a bottle of stronger gin.
Now we still haven’t answered the question above and are up to about half a page already so what our advice is at this point is to ask yourself more questions, not just about strength but what do you want to get out of your coffee? Are you a fan of heavy bodied chocolatey flavours, or sumptuous mouthfeel, or fruity acidic sparkle, or earthy, tobaccoey flavours? There’s so much more to coffee than strength and if you think about it you can probably describe a coffee that you really enjoyed at some point.
This is what we ask people who come into the shop and ask for strong coffee and it usually starts an interesting conversation from which we can recommend something from our range.
In conclusion, there are no stronger coffees but there will be attributes, flavours, and brewing methods that you personally rate strongly so try to work out what they are and then explore in that direction.