It is very important for people traveling by airplane this Thanksgiving to consider the consistency of their pies.

They must be firm. If your pie’s interior is found to be too soupy, that culinary labor of love might be banned from boarding. And don’t try to slip pie by the agents of the Transportation Security Administration. Expect the same degree of scrutiny your pie might get from the judges at a county fair.

“As a general rule of thumb,” the TSA advises, “if you can spread it, spill it, spray it, pump it or pour it, then it’s usually in the category of a (prohibited) liquid or gel.”

Could...