How to maintain the standard of high quality coffee produced by coffee utensils and coffee processing factories

How to operate a siphon kettle

The physical properties of siphon coffee may be complicated, but the process is not mysterious. Coffee has nothing to do with your attitude, handmade bamboo sticks or mixing techniques, because no matter what method is used, a good siphon pot can achieve a reasonable amount of uniform extraction from the whole range of coffee extraction at the right temperature.

When the upper kettle tightens the lower kettle, a closed system is formed, which contains water, air and steam. When the kettle is heated, the pressure of air and water vapor increases. When the pressure in the lower pot exceeds an atmospheric pressure, the water in the lower pot can be forced into the upper pot through the catheter at the lower end of the upper pot. It should be noted that although the air pressure in the lower pot exceeds an atmospheric pressure, the water inhaled in the upper pot does not need to boil.

Once the water level in the kettle falls below the conduit, the system is no longer closed, air and water vapor will overflow through the conduit, and the water slowly begins to boil. Due to the release of air and water vapor, another water vapor will be formed, and the ratio of water vapor to air in the kettle will increase. In order to achieve an effective seepage velocity, there must be a certain ratio of water vapor to air. If the water level in the starting pot is smaller than the capacity of the pot, then the steaming time will be longer in order to meet a certain ratio of water vapor to air.

After removing the heat source, the water vapor in the kettle cools and condenses, reducing the overall internal pressure. When the overall internal pressure is less than the external pressure, the liquid is forced to flow back to the next pot.

When refluxing, there will be a certain amount of friction on the wall of the upper pot, and the liquid will generally find the place with the least resistance to pass through, and the resistance around the upper pot will make the coffee liquid gather and flow down to the center. Therefore, the author recommends that at the beginning of the seepage, a slight stirring should be used to make a certain amount of coffee powder move away from the pot wall to the center, and a proper stirring can rebalance the resistance in the pot, thus making the extraction more uniform.