Chamber Vacuum Sealer: device that creates a low pressure within a chamber before sealing the bag. Equipped with a powerful pump, it can pull up to 99.9% of air from the bag, allowing for a tight seal and allowing for better thermal conductivity.

Cook-Chill: The process of cooking food until they are done or almost done and then rapidly chilling them until they are needed. Cooked foods must be chilled to 41°F or below within two hours of being removed from the water bath.

Compression: Food may be compressed and change texture from the compact packaging process of a chamber vacuum sealer. This allows for manipulation of textures and densities, while having little to no effect on flavor. During the process, porous foods, such as watermelon, are compressed under 99.9% vacuum, allowing the collapse of internal cells; all the while maintaining structural integrity. The juices of the watermelon are forced into the porous fruit, while all air is extracted. Compressed watermelon will resemble sashimi grade tuna, when compressed.

External Vacuum Sealer: A vacuum pump device that clamps to the outside of a vacuum pouch, pulls out as much air as possible and seals the pouch. This process does not create a true vacuum. They present a challenge when liquids are in the bag, since the pump will pull any content from the bag by way of suction.

Food Safety: The practice of clean and sanitary food preparation. This involves proper storage, refrigeration, handling of ingredients, maintenance of equipment and proper cooking temperatures to ensure that harmful pathogens are reduced or eliminated altogether.

For more information on Food Safety, please visit the United States FDA website.

HACCP Plan: A Hazard Analysis Critical Control Point Plan for Reduced Oxygen Packaging (ROP), Modified Atmosphere Packaging (MAP) and, in some jurisdictions, the entire Sous Vide process, is required or highly recommended for vacuum sealing foods and sous vide cooking.

Originally developed in the 1960s by NASA, HACCP is a series of seven steps:

• Conduct a hazard analysis.
• Identify critical control points.
• Establish critical limits for each critical control point.
• Establish critical control point monitoring requirements.
• Establish procedures for ensuring the HACCP system is working as intended.
• Establish corrective actions.
• Establish record keeping procedures

For more information on HACCP, please visit the United States FDA website on HACCP.

Infusions: Adding additional liquids to a compression process (see Compression) creates a rapid infusion—especially with more porous foods. Pickled and infused foods occur instantly. Cucumber, for example, will pickle instantly, while still remaining crisp and green, as the acid has not had enough time to react with the chlorophyll.

PID Controller: A proportional–integral–derivative controller (PID) is a generic control loop feedback mechanism (controller) widely used in industrial control systems – a PID is the most commonly used feedback controller, and the “brain” inside all PolyScience thermal immersion circulators. A PID controller calculates an “error” value as the difference between a measured process variable and a desired set point. The controller attempts to minimize the error by adjusting the process control inputs.

Sous Vide: A cooking method in which food is vacuum sealed in a plastic pouch and then cooked at a gentle temperature in a precisely controlled water bath. The literal French-to-English translation is “under empty,” but often referred to as “under vacuum” or “under pressure.”

Tenderness: Tender or delicate foods (fish, shellfish, foie gras, beef or pork tenderloin, lamb chops) need only to be brought to the desired serving temperature to be delicious and ready to eat. Extended cooking times can result in their becoming overly tender to the point of mushiness. Portioned chicken breasts and tender steaks typically take a minimum of one or two hours, depending on thickness.

Tougher foods (roasts, grass fed cuts, game, short ribs) will be brought to temperature based on the thickness of the portion, but then benefit from slow low cooking for hours to tenderize them. Skirt steaks and top round roasts typically take a minimum of six hours and a maximum of twelve hours. Ribs and briskets cook for twenty-four to forty-eight hours.

Thermal Immersion Circulator (or simply Circulator): An electrically powered device that circulates and heats a liquid kept at an accurate and stable temperature. It is comprised of a circulator pump, a heating element immersed in the fluid, an accurate temperature probe, and control circuitry.

Thickness: A common method for determining cook time. How long it takes a given portion of food to come to temperature depends on the thickness of the portion, not the total weight. Cooking time increases exponential to thickness. A 4 inch thick steak needs at least 3 times of cooking time than a 2 inch thick steak.

Tough Cuts: (See Tenderness)

Vacuum Bags / Pouches: Heat safe plastic bags / pouches that are sealed on three side, allowing for easy placement of vacuum sealed items. Most pouches used for sous vide are 3mil, boilable plastic material. These pouches have heat ratings that surpass boiling temperatures, prohibiting leaching of compounds and breakdown of materials until the rated temperature has been exceeded. Other heat ratings are available and approved for sous vide. PolyScience provides boilable vacuum pouches that are guaranteed BPA (bisphenol-A) and phthalates free.