Language: Japanese with English Subtitle. Introduce by The Creator of V60 Coffee filter, CAFEC CEO Shigeji Nakatsuka. “Pour Over” is one of the coffee brewing method. Though they all fall under the same method, but there are two kinds of pour over method; that is, “Osmotic-flow” and “Full immersion”. Osmotic-flow” is one of the pour over method to let water pass through coffee powder’ s filtering layer and induce a convection flow continuously then pull out only pleasant taste component from coffee powder by generating osmotic pressure continuously. The point of Osmotic-flow is to let water pass through the filtering layer then generate concentration difference between coffee essence and water, and the pleasant taste of coffee is brought out fully into coffee liquid by osmotic pressure. “Once water pass through the filtering layer completely, osmotic pressure becomes zero. At this point, pour water again to generate another osmotic pressure” ; pleasant taste component can be extracted fully by repeating this series of operation. As you know, water always pass through the filtering layer, so water never stay in a dripper. Full Immersion “Full immersion” is one of the hand-drip brewing method to soak coffee powder in water for a while; not induce a convection flow, when a time comes, then separate coffee powder and coffee liquid. In this case, all component of coffee powder, besides pleasant taste component but also unpleasant taste component come out into the coffee liquid. The biggest difference from Osmotic-flow is that the full immersion is to soak coffee powder in water by letting water stay in a dripper, by contrast, Osmotic-flow never let water stay in. Though coffee itself can be brewed because concentration difference is occurred between water and coffee essence by this full immersion method, but any filtering layer cannot be formed. more detail for osmotic flow may be see from below link. https://cafec-jp.com/brewing-guide/