Tamping your coffee grounds before extracting them is an important step in the process. It is most commonly done with espresso machines, but people may also wish to tamp their grounds in manual drip filters, moka pots or when making cold brew.
When in the puck, the grounds need to be as evenly distributed as possible because when hot water is forced through the coffee grounds at high pressure, the water will always flow through the path of least resistance. If you have gaps in the coffee grounds, the water will just escape this way, ignoring the grounds and resulting in a lacklustre brew.
So it’s vital to ensure that the grounds are tamped well for quality coffee with no waste. You will need:
To ensure the tamping is consistent each and every time, you need a few different factors:
With your ground coffee up to the brim. A single shot is usually 7 grams. Give it a quick shake to evenly distribute them
Using a curled finger, roughly level this off, and remove any excess. This will create the basic flat, packed consistency you need
Place the portafilter on a tamper mat or in a dedicated stand. A flat, clean surface will do if you don’t have one of these
With your tamper, press lightly on to the grounds. Leave the coffee to rest for a few seconds
Tamp for a second time, but offer a little more pressure. Anywhere between 8lbs and 30lbs of force is usually acceptable, but it is actually best to keep to the lower end usually with a good quality, heavy tamper
At this point, you can polish the shot. This is where you twist the tamper to create more of an even finish. Some say it isn’t necessary and is just cosmetic, but this could depend on your pressing quality