WHAT IS IT? So turns out putting butter in your coffee is a thing. Even the Daily Fail says so. There are lots of claims suggesting that it will make you shed half your body weight AND give you superhuman powers. But what does it taste like?

WHY IS IT QUESTIONABLE? Butter goes on toast. Milk goes in coffee. You don't muck with this established order, particularly at breakfast.

SAUNDERS SAYS: "Nice. It mellows out the coffee in a similar way to either a dash of milk or lump or sugar but with a feint buttery aftertaste. While it actually tasted pretty good, I was a bit disappointed not to be able to scale walls, have lazer vision or x-ray vision after but maybe I just need to keep drinking it."

SYMONDS SAYS: "I was pretty hopeful that this mix would pass the taste test. I could imagine a buttery flavour enhancing the flavour. I wasn't disappointed. The overall effect was much more subtle than I thought it would be - or maybe I just didn't put enough in? The butter gave the coffee an extra smooth mouthfeel and cut through the acidity of the black coffee. I'm not sure this is a substitute for a stonkingly good flat white, but when I run out of milk I would definitely stir a knob or two into my coffee."

THE VERDICT? Run out of milk? Give it a go.