This bottle is the most effective piece of drinkware I've ever encountered for keeping your drink cold and fizzy, hands down. Compared to having a can open to the air, or even a lidded cup, this bottle has a twist on top that pressurized the contents with a silicone seal. No container is going to break the laws of physics, but I left some seltzer in it over night just to see what would happen, and it still had some fizz left! Combined with the good insulation and ergonomic silicone loop grip, I am thrilled with this bottle.