Single-serve retortable pouches from Sonoco should begin appearing on grocery shelves in the near future. Until now, food manufacturers have had to source comparable materials from overseas.


Charlie the Tuna made a splash in 2000 with a retortable pouch that promised better-tasting product and greater shelf appeal, and Star Kist’s competitors quickly introduced their own versions of the new packaging. But only suppliers in Asia and Europe could provide pouches that could withstand retort temperatures—until now.

Hartsville, S.C.-based Sonoco Products Co. has concluded a three-year development process with the introduction of a three-ply, single-serve retort pouch. A U.S. manufacturer will roll out a line of products in the new pouch in the next few months, according to Jeffrey M. Schuetz, Sonoco’s director of global technology. He declined to identify the processor.

The foil-based, three-ply pouch is dubbed Sonotort and represents a departure from the typical four-ply construction. “For single-serve applications, we believe a nylon layer is an unnecessary component,” Schuetz explains. “The inclusion of nylon is really a strength issue in handling,” and smaller pouches can get by without it, resulting in a less costly package. Other layers are cast polypropylene film on the inside and an outer polyester layer surrounding foil. A clear foil-free pouch also is available.

Sonoco is developing pouches for family-size portions and foodservice applications for quantities up to the equivalent of #10 cans. However, roll stock can be formed, filled and sealed more economically than pre-made pouches, so foodservice applications for Sonotort will be limited.

The company also has developed Sonocoat, an electron-beam technology that polymerizes printed flexible packaging and eliminates the need for reverse printing and lamination. “We’re in the R&D phase in terms of marrying Sonotort with Sonocoat,” says Schuetz, and that should further reduce processors’ packaging costs.

While suppliers of packaging materials continue to drive down costs, fill speeds remain a major impediment to a switch from cans to pouches. Pouches enjoy an advantage in faster processing time than cans, which also means less product abuse, but can filling systems still are significantly faster, giving them a total-cost advantage. Resolution of the filling bottleneck is expected to pave the way to greatly expanded use of retortable pouches.

Nylon bags on the inside and a caffeine-content declaration on the outside help distinguish Mighty Leaf’s products from other teas.

Sidebar: Form meets function in nylon tea bags

Upscale packaging’s role in commanding a premium price for food products is well established, but Gary Shinner had superior seeping in mind when he selected a nylon mesh for bags of Mighty Leaf Tea.

Not that the bags don’t add an elegant touch. Headline writers have taken liberties by describing them as silk, a forgivable mistake, given a retail price of $42 per 100 bags. They also add to product functionality, though, by allowing the tea to seep more easily and eliminating any flavor absorption by the bag.

Foodservice is the primary distribution channel for the Sausalito, Calif., firm, with spas and high-end restaurants accounting for the bulk of sales. The company built the packaging machine that gives a hand-sown look to the bags, according to Shinner, the CEO.

U.S. tea consumption is on a strong growth curve, and the premium segment is trending up sharply, according to Shinner. His firm offers 14 varieties to appeal to tea connoisseurs, but flavor is the second consideration in tea selection, he says. The first is caffeine level, and Mighty Leaf packaging describes the contents as less caffeine, more caffeine or caffeine free.