A coffee extraction apparatus includes: a grinder grinding whole beans into coffee powder having a preset size or less and discharging the coffee powder, a grinder inlet defined at a first side of the grinder to introduce the whole beans to the grinder, a grinder outlet defined at a second side of the grinder and discharging the coffee powder, and a first extractor. The first extractor includes: a receiver inlet that faces the grinder and that receives the discharged coffee powder, a filter part receiving the coffee powder through the receiver inlet and extracting coffee liquid by rotating the coffee powder with water of a first temperature, the first temperature being equal to or lower than 25 degrees Celsius, and a receiver that receives the water of the first temperature and that is configured to store the water of the first temperature or the extracted coffee liquid.

A two dimensional brew selection interface is used to present suggestions for configuring a plurality of brewing parameters used in a coffee brewing operation. The two dimensional brew selection interface may include a plurality of positions distributed across multiple dimensions, with each position mapped to a set of values for multiple brewing parameters, and one or more indicators associated with suggested combinations of brewing parameters may be presented on the two dimensional brew selection interface, e.g., based at least in part upon a user's history and/or feedback.

One form of a drip coffee machine comprises a water level sensor, a boiler, and a processor. The water level sensor is positioned within the drip coffee machine at a junction where a water tank connects to the drip coffee machine. The water level sensor comprises a pair of electrodes positioned within an interior region, wherein a resistance between the pair of electrodes indicates whether water is present in the water tank. The boiler comprises a heating element that is configured to heat water within the boiler. The processor is in communication with the water level sensor and the boiler, and is configured to turn on the heating element of the boiler and to turn off the heating element of the boiler based in part on the resistance between the pair of electrodes of the water level sensor.