Need to figure out how to size a filter basket?
Oftentimes espresso filter baskets come without any information written on them, so you have to figure out what is the optimal dose for the filter basket you’re working with, so here’s a quick 3 step guide on how to size a filter basket.
Step 1 – tare and dose
Tare off your portafilter on an electronic scale and dose finely ground coffee to a lightly heaped mound into the filter basket. The base of the mound should sit ever so slightly below the rim of the basket.
Step 2 – distribute
Evenly distribute the grinds by gently tapping the portafilter with your palm to settle the bed of coffee. This will allow the coffee bed to even out in density.
What you will find is that the mounded coffee collapses and fills in the areas around the edges of the basket where there wasn’t enough coffee. This is why in step 1 we dosed just below the top of the basket.
Alternatively, using your index finger, sweep the grinds across the whole basket surface (without pushing coffee down into the basket) to fill in areas around the outer edges where there is not enough coffee.
The coffee dose should fill the basket to the brim. If you have any excess coffee, the dose can be scraped off with a flat surface like a ruler.
Step 3 – weigh
Weigh and record the result.
Repeat the exercise two more times. The resulting masses should fall over a certain value and this should give you a pretty good indication as to whether you’re dealing with, for example, an 18-gram or a 22-gram basket.
You can safely increase or decrease your dose by 1 gram for the basket you just sized without issue. For example, after repeating the exercise three times the scale reads 17.4 grams, 18.2 grams and 18.5 grams; you can be fairly confident you’re dealing with an 18-gram basket. This means you can safely dose between 17 and 19 grams of coffee in the basket without too many problems.
Precision filter basket manufacturers like VST, IMS, E&B Lab (what we use at the school), and more recently to the market, Pullman will have a stated dose range recommendation like 20-22 grams for their baskets. Shooting for the middle when dialing in is always a good idea and if needed work your way up and down in dose from there should you require some tweaking.
If you have any questions on how to size a filter basket, let me know in the comments section below.