Chilled water extraction is a tried and true method for effectively separating trichomes from plant material. The cold water causes the area between the trichome head and stalk to become fragile, making separation and extraction easier and more efficient.
Instead of ice, a special vessel keeps the water below freezing temperatures. During the extraction process, the chilled water current gently grabs and holds the trichome head without the risk of plant material contamination. The trichome-saturated water is then filtered. During filtration, the collected material forms a layer of bubbles. This distinctive characteristic is often why water extracted material is known as “bubble hash”.