Yeast stays protected in retort “pouch-within-a-pouch”

Award: Highest Achievement

Winner: The “Smack Pack” (Wyest Laboratories)

The "Smack Pack" system from Wyeast Laboratories offers products for the home brewer, home vintner, breweries and wineries. It is reportedly the first retorted "pouch-within-a-pouch" liquid-yeast package marketed in the USA for the making of beer and wine. The standup pouches come in 50- and 125-milliliter sizes—one inside the other.

They are converted by Ampac Flexibles (www.ampaconline.com)—a unit of Ampac Packaging which also won a Gold Award in Packaging Excellence and a Gold Award in Technical Innovation.

Reasoning

The package activates the yeast in an easy two-step process. First, an inner packet containing a liquid-malt nutrient base is pushed to the corner of the outer, sealed retort pouch. This is done by feeling for the inner pouch from the outside of the outer pouch. The entire package is then placed in the palm of one hand; a firm "smack" on the area of the inner packet breaks the inner packet. This causes the contents to interact with the pure yeast and begin metabolizing.

"You can actually locate the inner pouch easily by feeling for it from the outside of the retort pouch," says Wyeast's Jenny Logsdon, general manager.

Mechanism

For home brewing or vintner enthusiasts, the process of selecting liquid yeast that meets performance expectations is critical. Such brewing-yeast products have traditionally been merchandized in dry form. More recently, liquid versions have been introduced in rigid containers.

But Wyeast says these didn't always include ultraviolet protection or oxygen barriers. So the company decided to take the category to a new level of quality and functionality with its innovative "pouch-within-a-pouch" construction. The company believes it's the first on the market with a flexible pouch format instead of the tube-like, rigid plastic containers competitors used in the past.

Process

Wyeast follows a slightly different retort procedure. It retorts the new pouch earlier in the process (at about 121˚C), just after the smaller malt-nutrient pouch is inserted into the larger pouch. The pure liquid yeast is then filled into the pouch in a cleanroom environment to prevent any contamination. The filled-pouch assembly is then heat-sealed closed.

"We retort the pouch before filling to keep our yeast in a sterile environment," Logsdon explains.

To handle the heavy demands of retorting and to produce a pouch that can tackle high pressure, Ampac engineered a bottom gusset on the pouch to accommodate any swelling of the package that might take place as the yeast metabolizes and carbon dioxide is emitted, causing the internal pressure to increase.

Collapsed and flat during the inactive phase, the gussets give the product room to grow with increasing volume.

Appearance

In addition to improved functionality, Wyeast wanted a graphics billboard to create a uniform, family-look across its products. So Ampac supplies premade, three-side-sealed pouches made from a proprietary, high-barrier adhesive lamination containing foil that it reverse-prints by gravure in six colors on an eight-color Toshiba (www.toshiba-machine.co.jp) Sectional Drive press.

Ampac says the press enables it to generate cost-effective, high-definition printing. The product line highlights color-coded graphics that correspond to the contents and usage, courtesy of a retort grade of Roto Lamiall solvent-based inks from INX International Ink (www.inxinternational.com).

Tear notches on either side of the top of the package allow it to open easily.

Craig Rutman, director of sales at Ampac, admits that sophisticated, barrier structures can be prone to flex cracking, which can degrade barrier properties. But converting and printing this one wasn't a problem, he says.

"It's important to use special inks that can withstand retort temperatures," he notes. "The integrity of Ampac's retort pouches has been great," says Logsdon. "The company has excellent quality control, which is critical to our product. The execution of the graphics was also important. We recently revised our packaging and wanted to make sure that we partnered with a retort pouch manufacturer that could provide the visual impact we were after."

The pouches are filled manually on a proprietary band sealer, Asia Food Journal is told.

According to Rutman, the pouch structure had to be designed to deliver certain oxygen and ultraviolet barriers at a consistent level. And while meeting the barrier requirements, the heat seals had to remain uncompromised during the yeast-activation phase.

The back panel also instructs brewers to allow the pouch to incubate and swell for three hours or more at 21 to about 24˚C. So it's key that the seals withstand the internal pressure without rupturing. Die-cut notches allow for easy opening once the contents are ready for the next step of the brewing/winemaking process.