Doctor Brown’s Cel-Ray can lose its fizz.

I went over to pick up my Christmas Eve take-out. Countermen at the kosher deli are Hispanic now, but there’s still Morris, the old Jewish deli guy who takes pride in checking my orders.

“When I saw it was missing,” he said, “I made sure they put in a Cel-Ray instead of one of the ginger ales.”

Doctor Brown’s celery tonic was popular when the Lower East Side of Manhattan was a center of immigrant Jewish life a century ago. Even before my time.

Morris had a large take-out bag of his own. “Big party tomorrow,” he said.

I stared at him.

“We have a mixed family,” he said. “Everybody gets together for Christmas, maybe forty, fifty people. It’s great.”

Ethnic tastes fade. After a generation or two, they blend with other palates, or disappear. Blini and vodka if you used to be Russian, falafel and shawarma if you once were Israeli, celery tonic if some ancestor passed through the Lower East Side. At first, their tastes evoke a regretful pang, then a faint smile, then nothing much. Plum pudding, fruitcake, a nice Rumanian pastrami on rye. Whatever.

Truth be told, celery tonic tastes weird even before the bubbles go.