Red Sports Water Bottle

 

When brewing coffee, many people choose ceramic cups or glass cups instead of stainless steel cups. Why is this?

 

In fact, this is closely related to the thermal conductivity of the cup material.

 

After brewing coffee or tea, the heat of the coffee and tea will be transferred to the cup by heat conduction, and the cup will transfer the heat to the air.

 

Studies have shown that the thermal conductivity of stainless steel cups is the highest among the three materials (14.3 W/mK).

 

This high thermal conductivity and the relatively fast temperature balance between the cup and the liquid mean that the liquid in the stainless steel cup will cool down quickly.

 

The thermal conductivity of ceramic cups is about 3.8 W/mK, and the thermal conductivity of glass cups is about 1.1 W/mK.

 

It can be concluded that among the above three materials, the liquid can maintain a higher temperature in a glass cup for the longest time.

 

Since glass cups have the slowest heat dissipation and the best heat preservation effect, why are the cups in coffee shops generally not glass cups but ceramic cups?

 

On the one hand, Europeans were already using ceramic cups to drink coffee in the 15th century, while glass was not industrialized until the 19th century.

 

Therefore, the traditional culture of coffee determines that ceramic cups are still used as coffee cups.

 

On the other hand, glass cups are prone to cracks and surface scratches after collision, which will affect the appearance.

 

In fact, as long as the ceramic cup is made slightly thicker than the glass cup, the same insulation effect can be achieved as the glass cup.

 

The same is true for drinking beer with glass cups.

 

Glass cups can effectively reduce the heat exchange between the external environment and the iced beer, which can keep the beer at a lower temperature for a longer time.