Why do Ball Park franks plump when you cook 'em?

I read that hot dogs are pretty much mostly fat and water with some odd ball parts for protein. (Of course, this was in Biggest Secrets, but it sounds relatively true.) I’m comfortable with the fact, and enjoy a good hot dog from time to time with no ill regrets. What makes me wonder, is why do they plump when you cook 'em?

And as an extra aside, what really is in hot dogs? Partially-defatted beef fatty tissue?

I would think that the hot dogs plump up for the same reason many other types of food do as well:

Steam.

If you poke holes in the sides or make a big cut in them, they probably won’t plump up as much.

Not all hot dogs plump when you cook them. Those who do have cereal fillers. Think about how oatmeal, cream of wheat etc get bigger once cooked.

I don’t know exactly what fillers they use but the above is an example.

And the cereal fill plumps up because of steam, doesn’t it? What other force would cause it?

Do you really want to know? It’s not like their health food or anything. I’d rather not know to be honest with you.

Apparently you already know.

And as an extra aside, what really is in hot dogs? Partially-defatted beef fatty tissue?

Ingredients from a hot dog package: Mechanically separated chicken, pork fat, water, dextrose, salt, corn syrup, modified corn starch, flavorings, sodium phosphates, smoke flavorings, sugar, sodium erythorbate, sodium nitrate.

I think I posted the ingredients list from an all-beef hot dog package once, let me check…

This isn’t it, but it’s about hot dogs You can probably find it eventually, if you’re really interested.

Oatmeal doesn’t “plump” because it’s heated, it’s because it has absorbed hot water. The hot dog has not had any ingredients added, so all we can assume is that some ingredient, probably water, is allowed to expand, but (and this is probably the important part) retained, so the volume increases.

Incedentally, what a lame marketing ploy. Are we really supposed to believe that we get more for our money after they’re cooked?

They are made extruded into forms instead of just extruded.

Think of it as if they are being “packed sideways”.
Just as a wool sweater will shrink up and get wider at the same time, there is a “shrinkage direction” on hotdogs, depending which way the meat was stretched in the manufacture.

They get plumper than regular hot dogs, but at the same time they get shorter than regular hotdogs.
You end up with the same volume

Oh, that does make sense. Hmmm…

They plump up because they’re happy to see you.

Yeah, but don’t most hot dogs plump a little? If you don’t poke holes in them, they usually split.

[partial hijack]

A couple of semesters ago in my Chemistry class, we had to do a lab that required us to find the fat content in potato chips and hotdogs. Some things I learned from this:

  1. Protein reagent is nasty, nasty stuff and will pretty much dissolve your skin the same way it dissolves hot dogs.

  2. The smell of hot dogs dissolved with protein reagent is a permeating stench that WILL NOT fade from your person until you take a long, hot shower.

  3. Chemistry just does not seem very scientific when one is putting partially dissolved hot dogs into a centrifuge.

  4. Hot dogs have A LOT of fat content. (But I still love 'em. :D)

[/partial hijack]

Oddly enough, Ball Park Franks came in first in the blind taste test for commercial wieners carried out a year ago by COOK’S ILLUSTRATED magazine. Nathan’s Famous, MY brand of choice, came in second.

Curious, and being a good little Christopher Kimball worshiper, I went out and bought a package. They sure did plump up, but they tasted awful. Bland and watery.

It was back to Nathan’s for me with my maybe-thrice-yearly hot dog purchases (a nice way to use up leftover chili), and I hope they got demoted because they’re a NYC brand.