George Hamilton, main football commentator on Irish broadcaster RTÉ, is very fond of a groan-inducing pun. This evening, while referring to a Tunisian player who plays in Dijon in France, he said, That pass doesn’t cut the mustard!

Dijon, mustard… you get it.

Anyway, this made me wonder why, when something isn’t up to the standard we desire, we say it doesn’t cut the mustard? Mustard is a sauce! What can cut the mustard!? You could probably separate some mustard into two parts by pushing it aside with a knife, but that’s not really cutting the mustard. In fact, it’s so difficult to successfully cut mustard that it seems terribly unfair to criticise something for not being able to do so. It’d make more sense to praise something surprisingly successful by saying that it cuts the mustard.

But of course, as is always the case with such expressions, there’s a certain logic to them that isn’t apparent on the surface. First of all: why mustard?

We perhaps take the condiment for granted now, but in medieval England it was highly prized. Much as today, a Sunday roast beef was a staple of the English diet. Roast beef on its own is OK, but mustard was the favourite accompaniment, as it brought out the taste of the meat so well.

Mustard then developed quite a reputation, because it was so popular, but also because it’s so hot. This is where the phrase keen as mustard comes from. Someone so keen was hot like mustard because they were fired up with enthusiasm. Mustard is also probably where the term hot stuff comes from. In the past you could even say someone was mustard, though that’s been lost to time.

But what about to cut the mustard? That still doesn’t make sense, does it? Well, it doesn’t if you think of mustard purely as a condiment, but mustard the condiment comes from mustard the plant. And if you want to make yourself some delicious mustard for your roast beef dinner, you have to harvest some mustard seeds. And to do so, you’ve got to cut some mustard (plants). Harvesting mustard was a metaphor for providing something desired (which made more sense back in the day). If you didn’t cut the mustard, you weren’t giving someone what they wanted (mustard).

So yes, in the past, when mustard was both literally and metaphorically pretty hot stuff, these phrases made sense. Now, when mustard is just one condiment among many, easily available from the supermarket, the logic isn’t so obvious.