“I’d tap that”
This phrase is a condensation of the colloquial expression:
“If only I could tap and sell that.” -or-
“You could tap and sell that.”
The expression is derived from the practice of tapping a
keg of beer, or cask of wine; –whereby a
spigot valve is inserted into the side of the
keg, in order to tap the beer.
The expression figuratively means: “To
access something of value”
In the last decade, the expression has been further condensed to simply:
“You can tap that” -or- “I’d tap that”
It is often used in conjunction with a sexual connotation.