Lexicon - let's talk coffee

Burr grinder 

Most manual grinders use a conical burr mechanism to grind coffee beans. A conical serrated shaped Burr crushes the coffee beans against a fixed serrated surface facing opposite sides. This mechanism allows for more uniform grounds compared to those that use blade grinders. Manual burr grinders can be adjusted to get different grind sizes, usually with a dial.

Channeling

When water does not filter evenly through the grounds, but instead is distributed unevenly through one of the sides which has less resistance.

Compounds 

Substances naturally found in coffee that contribute to its unique flavour. 

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Extraction 

The process of coffee compounds being transferred from the coffee grounds to the water. These compounds get dissolved into the water.

Nine bars

The standard or accepted pressure at which espresso machines operate to extract espresso. Most espresso machines will allow its user to adjust the pressure if needed.

 

Over-extraction

The term that indicates an excessive extraction of coffee compounds to the one considered "standard". Over extraction is often associated with a bitter or astringent taste in the final cup.

Percolation 

The gradual dripping of water that has been filtered through the coffee grounds.
 

Ratio (water/coffee)

The amount of water in relation to coffee. For example, a 15 to 1 (15:1) ratio means for every gram of coffee, 15 grams of water will be used. The ratio can vary according to the brewer's taste.

Tamping 

Pressing coffee grounds using a “tamper” to pack them evenly and tightly inside the basket of an espresso machine. 

Tare (digital scale)

The act of putting something on a digital scale and then setting that weight at zero. This allows you to measure multiple items by using one container to hold different sources (e.g. beans and then water). 
 

Under-extraction 

The term that indicates an insufficient extraction of coffee compounds to the “standard”, Usually, an under-extracted cup will have an acidic, salty-like taste without body.