The Brewista Tornado Duo is a conical pour-over dripper made from sealed double-wall borosilicate glass. The "Duo" is that twin-wall build: an air gap between the two layers insulates the brew, holding temperature far more steadily than single-wall glass or plastic and keeping the outside cool to the touch.
Its defining feature is 18 internal ribs arranged in a tornado spiral. They lift the paper off the cone so water drains freely, and their spacing shapes the flow — wide and slow near the top, then tighter and faster as the ridges close in toward the tip, so a pour starts gently and accelerates through the bed. That gives a fast, clean, high-flow cup while the double wall keeps the water hot for even extraction. It has no valve — it is a straight percolation dripper.
It takes cone paper filters (Brewista's own #1 for the 1–2 cup body, #4 for the 2–4 cup) and comes in two sizes with gold-accent trim. Choose the Tornado Duo when you want a fast, heat-stable glass cone for clean, bright pour-overs.
Starting recipe: 15 g of coffee to 250 g of water (about 1:16.7), water around 93 °C, a medium grind, a bloom, then two even pours in slow circles, finishing around 2:30–3:00.