Science Questions

Why does beer seem to go flat after eating salty food?

Why, when someone drinks beer after having food with a lot of salt in it why does the beer seem to go flat quicker? Robin, Northampton

Chris - It’s all down to something called nucleation and that is that the salt in the drink, the little crystals, if you’ve got some of those stuck on your lips or still in your mouth the salt forms a rough surface for the beer bubbles (the carbon dioxide that makes beer fizzy) to form on. It’s much easier to form where there’s a little imperfection. The beer fizzes out and all the carbon dioxide gets released where the salt crystals are and that makes the beer go flat. You can demonstrate this for yourself if you take a bit of beer and pour some salt into the beer it should froth up. That’s the CO2 coming out.

November 2008