Recap and Glossary
Recap
- It is important to adhere to a protocol for when to change your grinder setting and for when you purge.
- Without an organised and well informed approach to your grinder, you can waste a lot of coffee.
- Grind retention should be measured and the size of your grinder purges should be based on the minimum amount of coffee needed for your grind adjustment to stabilise.
- Channelling is a critical unevenness in the flow of water through the coffee bed.
- It makes your coffee taste weaker, bitter and less balanced.
- There are many causes but the main causes are bumping the portafilter against something — usually the group head — when you insert it, and uneven distribution.
- We looked at a comprehensive list of trouble that can occur on bar, how to spot it and if you can resolve it on your own.
Glossary
Capacitor (Run-capacitor) The part on a grinder that helps create extra torque to get the motor spinning and to add efficiency while the motor is spinning.
Capillary action The ability of a liquid to flow in narrow spaces against the force of gravity.
Channelling: A critical unevenness during extraction, where a large amount of brew water travels through one localised areas.
Choke up your grinder Where beans have at some point been ground excessively fine and have compacted together so firmly that they are no longer able to slide out the grinder throat.
Convex tamper A tamper that has a base that is curved like a small section of a ball.
Dissolved coffee solids Parts of the coffee bean that have been removed from the coffee grinds and bonded with water molecules to become liquid.
Naked Portafilter A bottomless portafilter that has had the spouts and the bottom of the section that fits around the filter basket removed.
Side Channelling A form of channelling where the majority of the flow occurs around the edges of the coffee bed between the filter basket and the coffee puck.