Nucleus Coffee Tools, the brainchild of former World Barista Champion Sasa Sestic, is known in the specialty coffee space for its fantastic products that combine cutting-edge science with stunning design. One of its most innovative products is the Paragon brewer, which uses a technique called extract chilling to bring out even more nuance and flavour in your pour-over coffee, and this same approach has now been extended to espresso with the Paragon Espresso. As with the standard Paragon, the linchpin of the Paragon Espresso is the chilling rock, a food-safe titanium-coated 304-grade stainless steel sphere. The idea is that you leave these in the freezer, then pull them out and set them up in the stand before you start pulling your shots. The Paragon Espresso comes with 4 chilling rocks so that you can switch one out with another if you’re pulling multiple shots back-to-back and don’t want to wait for one rock to refreeze between shots. However, if you’re regularly serving more than 4 or 5 shots in a row, say if you find yourself offering extract-chilled shots and beverages in a commercial setting, you might need more than the standard offering. If this seems like a problem you might run into, we have a simple solution for you: get more rocks! Buy this set of 6 if you want to enjoy and offer extract-chilled espresso without temperature-related setbacks. Nucleus Paragon Chilling Rock features Extract chilling technology captures and retains up to 40% more aroma-volatile compounds from your brew, taking your pour-over to the next level. Cutting-edge and aesthetically appealing design. Food-safe titanium-coated 304-grade stainless steel outer surrounds the highly dense liquid core, keeping the rocks cool for a long time. Nucleus Paragon Chilling Rock specifications Dimensions (diameter): 30mm Material: food-safe titanium-coated 304-grade stainless steel, with liquid-gel core.