The Infinite Perfection of Taffy Pulling

Watching taffy being made is not only one of the great joys of summer — it’s also one of the great joys of mathematics.


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Taking a break from the sun, the sand and the squeals of wave-jumping children to pad over to the saltwater-taffy “shoppe” and watch the complex apparatus do its pully-twisty thing is, truly, one of the great joys of summer.

It also turns out to be one of the great joys of mathematics. In fact, a professor of fluid dynamics at the University of Wisconsin, Jean-Luc Thiffeault, whose field of study mixes mathematics and physics like the air and sugar that are taffy’s chief ingredients, has written an entire research paper — “A mathematical history of taffy pullers” — about the mathematical efficiency of taffy-making machines and the innovations over the years.

In a report on Thiffeault’s research, the Washington Post highlights some interesting tidbits about taffy’s history to chew on. Among them:

1: All that stretching and pulling and whiz-banging is not just show: Successful taffy making truly depends on it to get air into the mix and achieve its quintessentially taffyish texture.

2: In the olden days, back before the turn of the 20th century, all the pulling and twisting was done by hand, which was labor-intensive, unhygienic and, frankly, not terribly appetizing.

3: In the early 20th century, a flurry of taffy-minded inventors came up with mechanical inventions to improve the process and patented them.

4: One early model — the Nitz taffy puller, patented in 1918 — which used three rods to stretch, fold and loop the taffy, precisely mirrors a shape that mathematicians have been studying since the early 1970s. (Thiffeault was super-excited when he made the discovery — the Washington Post calls it a “Eureka moment.”)

5: Many other taffy-machine models have used more than three rods to do the business of stretching and pulling, but Thiffeault says they pretty much all accomplished the same thing, taffywise.

6: The most-common model in use today uses four rods that spin, twist and pull the taffy in an infinite motion.

7: Thiffeault created a puller that uses six rods, contending that it is “more mathematically perfect,” as the Post puts it, than the usual four-rod puller. But he says that doesn’t mean that, from an engineering standpoint, it’s necessarily superior. So don’t expect big changes in the taffy world as a result.

Fascinating. And just the sort of thing that could put a person in the mood for taffy. Here’s a recipe to try — no fancy machine needed.

Photo courtesy of iStock

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