You can get the perfect amount of foam in your beer by tilting your glass a little. But obviously that's a LOT of work, so a design firm in Japan came up with a solution. They just unveiled a new beer can with TWO pull tabs instead of one, according to Food and Wine. They're staggered at an angle, and supposed to give you the perfect beer-to-foam ratio. You pull the one on the left first to open the can part way. Then you pour half of your beer straight into the center of the glass. That leaves you with mostly foam. But then you pull the second tab, and pour the rest of the beer in. And you end up with a 7-to-3 beer-foam ratio what they consider the perfect pour.
They say there are two main things that cause too much foam when pouring beer out of a can. There's a drop in air pressure inside the can when you open it. And as you pour, the way the beer contacts the opening of the can matters too. Their new double-pull-tab addresses both of those things. They posted a video that shows it in action. It doesn't sound like any major beer brands are planning to switch to a double-tab yet. So for now, it's just a proof-of-concept thing.