P 6.04 – Recap and Glossary

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  • Best practice when storing brewed coffee is to fill a vacuum flask to the brim and create an airtight seal.
  • This will allow the coffee to reach the equilibrium vapour pressure sooner, resulting in volatile aromatic gases remaining in solution.
  • The high level of dissolved CGAs in coffee are most stable when stored between 80 and 85° C.
  • Below 80° C, CGAs begin to break down into caffeic and quinic acid. This breakdown adds additional bitterness and sourness to a brew.
  • Ted Lingle (the author of the SCA Coffee Brewing Handbook) considers coffee to be unservable 30 minutes after it is brewed.
  • Hotplates are not an appropriate means of storing specialty coffee. They accelerate the loss of aromatics and the degradation of the coffee’s chemistry.



Equilibrium vapour pressure  The pressure of a vapour when it is condensing at the same rate at which its liquid state is evaporating

Headspace  The amount of room above a liquid in which vapour can build up, e.g., the amount of space between the liquid in a vacuum flask and the lid

Hermetically sealed  Possessing an airtight seal

Kinetic energy  The amount of energy it takes to bring an object from a standstill up to a certain speed

Proportional integral derivative (PID)  A control algorithm used in maintaining a target temperature with digital thermostats in modern brewing equipment

Thermostat  A device that measures the temperature of a body of water and restricts the flow of energy into a heating element

Vacuum flask  A double-walled insulating vessel with a vacuum between the walls to reduce the thermal conductivity of the material from which the flask is made

Volatility  The ease with which a substance is converted to the gaseous state.

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