Coffee roasting apparatus, coffee brewing apparatus and coffee roasting method

1. A coffee roasting apparatus comprising:

a compartment for holding coffee beans;

a roasting element for roasting the coffee beans in said compartment; and

a controller configured to control the roasting element as a function of a change in a volume of the coffee beans residing in the compartment, wherein the controller is configured to control the roasting element in response to a monitored rate of change of the volume exceeding a predefined threshold, said predefined threshold indicating first cracking of said coffee beans.

2. The coffee roasting apparatus of claim 1 , wherein the controller is configured to control the roasting element in response to:

an increase in the monitored rate of change of the volume indicative of the start of the first cracking of the coffee beans; and/or

a decrease in the monitored rate of change of the volume indicative of the completion of the first cracking of the coffee beans.

3. The coffee roasting apparatus of claim 1 , further comprising a sensor arrangement configured to determine an unoccupied volume of the compartment, wherein the controller is further configured to control the roasting element in response to the sensor arrangement.

4. The coffee roasting apparatus of claim 3 , wherein the sensor arrangement comprises a sensor configured to transmit a signal into the compartment towards said coffee beans and to detect a reflection of said signal.

5. The coffee roasting apparatus of claim 4 , wherein the signal is an optical signal or an acoustic signal.

6. The coffee roasting apparatus of claim 3 , wherein the sensor arrangement is further configured to determine an initial volume occupied by said coffee beans and to monitor a change in said initial volume.

7. The coffee roasting apparatus of claim 1 , wherein the controller is configured to enable the roasting element for a predefined time period upon the monitored rate of change of the volume indicative of said first cracking exceeding the predefined threshold.

8. The coffee roasting apparatus of claim 1 , further comprising a data storage element configured to store a measured change in an unoccupied volume in the compartment as a function of time to define a roasting profile of a type of coffee beans, wherein:

the controller is further configured to program said data storage element; and/or

the controller is further configured to control the roasting element in accordance with the stored roasting profile in response to a user defining a degree of roasting for said type of coffee beans.

9. The coffee roasting apparatus of claim 1 , wherein the controller is configured to disable the roasting element upon the monitored rate of change of the volume exceeding the predefined threshold.

10. A coffee brewing apparatus including the coffee roasting apparatus of claim 1 .

11. A method of roasting coffee beans, the method comprising:

heating the coffee beans to roast the coffee beans;

monitoring a rate of change of volume of the coffee beans during said heating; and

terminating said heating in response to said volume change rate exceeding a defined threshold, said defined threshold indicating first cracking of said coffee beans.

12. The method of claim 11 , wherein the monitoring a rate of change of said volume comprises:

monitoring an increase in the monitored rate of change of volume indicative of the start of first cracking of the coffee beans; and/or

monitoring a decrease in the monitored rate of change of volume indicative of the completion of first cracking of the coffee beans.

13. The method of claim 11 , wherein terminating said heating in response to said volume change exceeding a defined threshold comprises terminating said heating after a predefined period of time upon said volume change rate exceeding the defined threshold.