I always forget whether you should adjust your grind size to be coarser or finer
Didn’t deploy this feature because I eventually remembered.
Coffee Extraction Theory 101
If you are new to dialing in espresso the rule of thumb is that you should use 16–18.5 grams of ground coffee beans and take 25–30 seconds to extract a 36g shot. Because the different flavor compounds in a coffee bean have a different solubility rate in water, extraction time is used as a proxy. Generally if it took:
- more than 30 seconds the shot is likely over extracted and tastes bitter
- less than 25 seconds it is likely under extracted and tastes sour
Adjusting the grind size is the main way in which you change your extraction times
If the shot is too slow, you need a coarser grind size. Because the bigger the particle size of the ground coffee the faster water will flow through.
Conversely, if the shot is too fast you need a finer grind size.
Are you confused yet?
Me too. As a newbie to espresso making, it was a bit too much so I decided to add a feature to WTFellow.
WTFellow (v 1.1)
First, there would be the grind size module that I had already built (and wrote about). Second, would be the dialing in module which would tell me to increase or decrease my grind size setting depending on how long it took to extract the shot.
The user would be directed to the dialing in module by clicking the “Dial In” button that appeared after the grind size was calculated.
What I learnt
- More Javascript. Especially event listener and console logs.
- More Git. Made my first branch and pull request.