Double entendre

The French have long had an enviable drinking culture. While I have always thought that they preferred wine to beer I was pleased to meet an onion-muncher who explained to me how to get the fine creamy head on your northern pint. It comes, he said to me, from ze use of ze sprinkler on ze head of ze pump. Thanking Frenchie for this information I explained that the word was sparkler and quickly exited the gents.