Recent remarks from Levi Strauss CEO Chip Bergh have gained almost as much notoriety around the globe as the multinational company’s celebrated jeans.
At Fortune’s Brainstorm Green Conference last week, Bergh raised eyebrows when he admitted the jeans that he wore to the event “have yet to see a washing machine.”
He quickly added with a laugh, “I know that sounds totally disgusting, I know it does, but believe me it can be done- you can spot clean it, you can air dry it and it’s fine.”
The culturally iconic company has run campaigns encouraging denim-lovers to wash their jeans rarely, if at all, over the last few years, suggesting freezing them instead “to kill germs and stink.”
Does the claim hold up, that you can freeze your jeans and still kill most bacteria?
The short answer- no.
“Bacteria are really highly-evolved little creatures and they’re evolved to withstand really extreme environments,” said Adam Perez, a Stanford microbiologist and doctoral student. “They’re actually designed to be able to freeze.”
Perez and several of his cohorts at Stanford were kind enough to perform an experiment for us.
We traveled to an environment that is filled with bacteria, the zoo, and showcased a brand new pair of Levi’s jeans while we fed the lemurs, handled worms, grazed with the goats and transplanted saliva from the local zebu (a species of cattle) onto the pants.
Next, we took the jeans to the Stanford lab for analysis. Perez swabbed the jeans for bacteria, both inside and out, before we froze them overnight and after.
Perez found what he initially suspected, that freezing bacteria does not work to kill it
[in fact, he says microbiologists often freeze bacteria to preserve the colonies].
You can see that there’s also lots of bacteria still on this plate, about the same amount that we had before we froze them,” said Perez, holding up a petri dish containing bacteria extracted from the jeans after they were frozen. “So this shows pretty conclusively that freezing your jeans does not kill the bacteria, at all!”
The Stanford lab’s industrial freezer, mind you, is also significantly colder than what you might find in your house. Another reason the claim is discredited.
We reached out Levi’s for comment.
Spokesperson Marisa Giller said the company had changed its position on freezing jeans, “following further studies.”
Giller said CEO Chip Bergh had never endorsed such a method, but rather had encouraged Levi’s consumers to conserve water and be mindful of their environmental footprint.
“The main point here is reminding consumers the positive impact they can make on the environment just by changing their washing habits,” Giller said.
Meanwhile, news outlets like the newly-created, data responsive Vox have also pointed out holes in the claim.