Pumpy?

The OED only has 'pumpy' as part of 'rumpy-pumpy' and 'rumpo'.

I was looking for it because of a reference in old episode of
'Midsomer Murders'. It might be entirely spurious and even a joke
because the character who makes 'pumpy' is rather keen on rumpy-pumpy
as well.

I thought I'd ask here, just in case - I can't find anything useful on
google.

The idea, in 'Midsomer Murders' is that it's a name for a drink made
from distilled scrumpy and garlic - it sounds an interesting
combination.

So, is it just a coinage in the series, or is there a drink made from
distilled scrumpy and garlic, and, if there is, has anybody heard it
called 'pumpy'?

.