Why don’t roasted coffee beans pop at once?

Why don’t roasted coffee beans pop at the same time?

Roasting coffee beans is one of the important steps in making coffee, which can make the coffee beans emit aroma and flavor. However, sometimes we find that not all coffee beans will burst during the roasting process. So, why don't roasted coffee beans burst? The following will analyze it from several aspects.

1. Difference in raw materials

First, we need to understand that each batch of coffee beans may have differences in variety, origin, processing methods, etc. These factors will affect the moisture content and density of each coffee bean. Coffee beans with higher moisture content and lower density are more likely to produce a fluffy effect during heating and eventually cause bursting.

In addition, there may be quality control issues during the picking, handling and storage process, such as underdrying or moisture, which may cause the storage period of some or all batches to be extended. These factors may cause some coffee beans to not crack during the roasting process.

2. Control of cooking parameters

In addition to raw material factors, the control of roasting parameters is also one of the important factors affecting whether coffee beans burst. For example, parameters such as temperature, time and stirring speed will affect the roasting process.

If the temperature is too high or the time is too long, the surface of the coffee beans may be over-charred, while the inside still retains a high moisture content. In this case, due to the accumulation of internal moisture, it cannot be released quickly when heated, and ultimately causes the coffee beans to not burst.

In addition, in terms of stirring speed, stirring too fast or too slow may affect the uniformity of heating. If the heating is uneven, the pressure accumulation in some parts will exceed the tolerance range and burst; on the contrary, if the heating is too uniform, it will not form enough pressure difference to cause bursting.

3. Environmental conditions

The last factor is environmental conditions, such as humidity, altitude and temperature, which will affect the roasting process of coffee beans.

A high humidity environment will cause the coffee beans to absorb more water, resulting in an increase in moisture content. This will make it take longer to reach the crackling point during the roasting process, or it may not reach the crackling point at all.

In addition, the altitude will also affect the choice of roasting parameters. At higher altitudes, the boiling point of water is lower due to the lower atmospheric pressure. Therefore, when roasting coffee beans in these areas, parameters such as temperature and time need to be adjusted.

in conclusion

In summary, the different cracks in the roasting process of coffee beans may be caused by the combined effect of various factors such as raw material differences, roasting parameter control and environmental conditions. Understanding and mastering these factors is crucial to improving the quality and taste of coffee.