With the Filter Screen, the minimum dose is around 12g which is enough for the filter screen to still rest on top of the coffee. Less than that, and the filter screen will “bottom out” on the lower taper of the basket and will not be ideal for brewing.
The Filter Paper allow you to experiment with lower doses. We have successfully brewed with 8g by placing one paper filter on top of the coffee and then the filter screen on top.
Fill the basket with hot water just off the boil up to 5-8mm below the rim. Do not weight the water into the basket and potentially under-fill the basket.
The professional basket has many holes on the bottom, it requires the beans to be ground by you right before you want to make the coffee. A chopping blade grinder, or the all-purpose small ceramic burr grinders will not work very well.
A hand grinder is a good investment as they are inexpensive and not much can go wrong, something like a Kinu, Commandante, Orphan Espresso, Helor, 1Z Presso or a Made by Knock grinder would work. Not a Porlex or Hario as they cannot grind fine enough. The Robot uses a real espresso grind, not drip coffee grind.
The Robot is exactly the same as any high-end coffee machine, for example the advanced basics would be:
- Use fresh coffee from a local coffee roaster (local so it is fresh).
- Use a decent burr coffee grinder and grind just before you will use it.
- The grind setting will roughly be in the same area as your grind setting for a regular machine.
- Start with a 16g dose and work from there.
- For best results use the naked (bottomless) portafilter.
The pressurised basket has only 1 small hole on the bottom. This is designed for use with pre-ground coffee (those supermarket vacuum packed bricks or tins). Each pressurised basket comes with a spoon which doses roughly 7g of coffee per level spoon.
You must use the portafilter spout with the pressurised basket, the pressurised basket has flow restrictor in place which is a precision stamped orifice, properly calibrated to create sufficient back pressure to mimic extraction pressure of around 8 bars. If you do not use the portafilter spout, you will get a very small stream of coffee exiting the basket and it will make a huge frothy mess in your cup.
It will raise the temperature of the coffee drink enormously if you pull a dummy shot with hot water first.
It would be a good idea to pull a few hot water dummy shots with the pressurised basket every few months, this will keep the flow restrictor clear. An even better choice would be a very weak solution of an espresso machine cleaner, pull a few shots with that and then follow it up with plain hot water.
Please visit 'Brewing Tips' for more information on how to make good coffee.