How Do They Get the Salt Inside Roasted In-Shell Peanuts?


Salted or unsalted? That's a question that confronts us all when buying peanuts. And that goes for shelled peanuts you find in the grocery aisle as well as the in-shell peanuts you find in the produce section.

When it comes to in-shell peanuts, the biggest brand on the market is Hampton Farms. I talked to my good friend Tom Nolan at Hampton Farms to learn more about the mysterious process they use to salt the peanuts before you crack the shell. It turns out it's as simple as a high school science class.

"As the air is sucked out of the peanuts, the salty brine gets pulled inside the shells"

According to Tom, they begin with raw (unroasted) peanuts which are loaded into 1,000-pound vats called hoppers. Then the hoppers are filled with a simple brine made from water and salt (about 1% to 2% salt by weight—the exact amount is a trade secret). Once the hoppers are full, a vacuum pump is applied for about a minute, which pulls all of the air out of the hopper. As the air is sucked out of the peanuts, the salty brine gets pulled inside the shells (physics class flashback). The process is repeated one more time to ensure that the brine has entered all of the peanut shells.

The brine is then drained from the peanuts, and next the peanuts go into a dryer, where the water evaporates, leaving behind a light coating of NaCl (a.k.a. sodium chloride a.k.a. salt) on the peanuts inside the shell. After about 20 minutes in the dryer, the peanuts are dry roasted to add that toasty flavor we all associate with peanuts, which takes about another 25 minutes. In all, it takes just about an hour to complete this entire in-shell peanut-salting process.

It's also interesting to note that peanut companies are now using this in-shell salting technique to impart other exciting new flavors to peanuts. Hampton Farms just introduced Hickory Smoked flavored in-shell peanuts that have a rich smoky flavor. This is achieved by adding smoke flavor to the brine. Another company called Sachs offers Tabasco flavored in-shell peanuts. The possibilities for flavoring peanuts seem endless!

Do you like to eat salted in-shell peanuts? Ever tried flavored in-shell peanuts?