Passive metering for pour-over coffee brewing
In pour-over brewing, a vessel containing water can be suspended over a brew basket so that the water can drain, under gravity, into the brew basket and onto the coffee, and the water level in the brew basket is used to regulate the flow of water from the vessel. A vessel that is closed, other than the mouth thereof, and containing brew-heated water, is suspended over the brew basket so that the water can drain from the mouth of the vessel into the brew basket and into the ground coffee to brew liquid coffee, which drains into a container. Rising of the water in the brew basket causes interruption of drainage of the water from the mouth of the vessel into the brew basket, and lowering of the water in the brew basket causes resumption of drainage of the water from the mouth of the vessel into the brew basket.
1. A passive metering valve, comprising:
a float portion;
a reservoir carried by the float portion;
the reservoir having an open superior end adapted for fluid communication with a water vessel to receive water therefrom;
the passive metering valve having at least one overflow path adapted for overflowing into a brew basket.
2. The passive metering valve of claim 1 , wherein:
the reservoir is formed by a tube depending from and sealed off from the float portion;
the at least one overflow path is formed by at least one water drainage aperture longitudinally spaced from the float portion;
the open superior end results from an end of the tube remote from the float portion being open for receiving the water from the vessel.
3. A passive metering valve, comprising:
a float portion;
a reservoir carried by the float portion;
the reservoir having an open superior end adapted for fluid communication with a water vessel to receive water therefrom;
the passive metering valve having at least one overflow path adapted for overflowing into a brew basket;
wherein, in use:
rising of a level of the water in the brew basket causes interruption of drainage of the water from the mouth of the vessel into the brew basket by flotation of the float portion raising the passive metering valve until the water in the reservoir obstructs the flow of air into the vessel; and
lowering of the level of the water in the brew basket causes resumption of drainage of the water from the mouth of the vessel into the brew basket by flotation of the float portion lowering the passive metering valve until the flow of air into the vessel is unobstructed by the water in the reservoir and the water in the reservoir overflows from the reservoir into the brew basket upon displacement by the water from the vessel.
4. A passive metering system, comprising:
the passive metering valve of claim 3 ;
the water vessel; and
the brew basket.
5. The passive metering valve of claim 3 , wherein:
the reservoir is formed by a tube depending from and sealed off from the float portion;
the at least one overflow path is at least partially formed by at least one water drainage aperture longitudinally spaced from the float portion;
the open superior end results from an end of the tube remote from the float portion being open for receiving the water from the vessel;
wherein, in use:
rising of the level of the water in the brew basket causes interruption of drainage of the water from the mouth of the vessel into the brew basket by flotation of the float portion raising the passive metering valve until the water in the tube obstructs the flow of air into the vessel; and
lowering of the level of the water in the brew basket causes resumption of drainage of the water from the mouth of the vessel into the brew basket by flotation of the float portion lowering the passive metering valve until the flow of air into the vessel is unobstructed by the water in the tube and the water in the tube can drain from the tube through the at least one water drainage aperture into the brew basket.