Ask Paul: What Exactly Is a Pellicle?

And why do fish need them?

Published Aug. 30, 2021.

Talk to anyone about smoking fish, and the conversation quickly turns to the pellicle. Smoking fish? Gotta have a good pellicle!

But what, exactly, is a pellicle?

From the Latin pellicula, meaning skin, the word refers to the surface layer on fish or meat. However, people – people who smoke food, I mean – use the word in two different ways, which becomes pernicious in trying to discuss the subject.

This first came to my attention during a conversation with Cook’s Illustrated Deputy Food Editor Andrea Geary and Boston University professor Greg Blonder. We were talking about a smoked salmon recipe that Andrea was developing. Dr. Blonder was describing what he calls “Diffusion Reduced Irreversible Polymerization (DRIP),” the process wherein proteins bond to each other as they gradually dry out. Like on the surface of smoked fish, for instance. 

We discussed pellicle formation, we were all puzzled, and suddenly it became clear that we were using the term “pellicle” in two different ways.

Charcuterie: The Craft of Salting, Smoking, and Curing by Michael Ruhlman and Brian Polcyn, is a classic, authoritative cookbook, much loved and sausage-grease-stained by professional and home cooks alike. It tells us, “Of smoking basics, the only issue that isn’t a matter of common sense is the importance of allowing the food to dry long enough before smoking to form a pellicle, a tacky surface that the smoke will stick to.”

Compare that statement to this one in Modernist Cuisine, the 2,500-page landmark of technical culinary expertise, which tells us that a pellicle is “the coating that forms from vapors, oils, and tars in smoke as they react with proteins, sugars, and starches on the food surface” during smoking.

To recap: Is the pellicle the thing that you need to form before you smoke your fish? Or the thing that smoking causes?

It’s easy to find books and articles that use the word one way or the other, but I haven’t found any that acknowledge point-blank: “Hey, this word is used with two different meanings and it’s confusing!” So I am here to say that.

Henceforth, I propose calling the tacky surface formed before smoking a film” and calling the glossy succulent surface formed during smoking a “bark.”

Ask Paul Adams, senior science research editor, about culinary ambiguities, terms of art, and useful distinctions:


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