You can ask Steve to help you, he is always as keen as mustard

[vectra]

Hello,

I asked my students to make up sentences with the idioms they are currently studying. Here is one of them:

You can ask Steve to help you, he is always as keen as mustard.

The expreession is 'as keen as mustard'.
The idea is Steve is always keen to help.
Is this expression still in use? I have not come across it often.

Thank you in advance.

[montfan]

* not a teacher

I've never heard "keen as mustard" used in American English. It's quite possible that its common in BrE as they use the word "keen" far more.

[Rover_KE]

Yes, it's fairly common in BE.

Rover

[Allen165]

Yes, it's fairly common in BE.

Rover

And why is mustard described as keen?

[Rover_KE]

And why is mustard described as keen?

Pass.

[bhaisahab]

And why is mustard described as keen?

One meaning of "keen" is "strong/intense".

[Tdol]

Have another mustard idiom: Cut the mustard - Idiom Definition - UsingEnglish.com

[probus]

I haven't used "cut the mustard" or "keen as mustard" since they let me out of the trenches in 1918.

[Vidor]

Never heard this in AmE.