How the FoodSaver System Works

As you may have imagined, the FoodSaver System uses a vacuum device to remove air surrounding the food or drink you want to preserve. As with any vacuum, air is moved from one place to another, which creates a drop in pressure at one point and an increase in pressure at another point. As you may remember from physics class, nature abhors a vacuum and tends to prefer equilibrium. When the pressure is lower in a space than the ambient air pressure, air moves to fill the void.

Air's movement to fill a void is called communication, and air can communicate quickly -- at a speed of about 1,115 feet per second (340 meters per second) [source: LaesieWorks]. That's as fast as the speed of sound, but that speed can be overcome. This is what the FoodSaver system, and any device that creates suction by creating a drop in air pressure, does. Using a motor that spins a series of fans, air is pushed out of the space -- in the case of the FoodSaver, a plastic food storage bag -- faster than the ambient air can communicate into the void that's created. As a result, the bag shrinks around the food and is essentially vacuum-sealed. Upon opening, the bag will make a whooshing sound as air outside the vacuumed space rushes in to fill the void.

The result? Without ambient air exchange, food sealed by the FoodSaver stays fresh about five times longer than it would without storage [source: FoodSaver]. One review of the FoodSaver V3840 reported that sealed packages of meat showed no signs of freezer burn after a month in the freezer [source: Kitchen Contraptions].

The mechanics of the FoodSaver vacuum also allow for quick food preparation as well as storage. A method of marinating called [https://recipes.howstuffworks.com/tools-and-techniques/sous-vide.htm]sous vide ("under vacuum" in French) uses a vacuum sealer hose extension and a tray to remove air and open meat for marinating. The void creates a suction effect within the tissue of the meat, causing it to absorb marinades quickly. The FoodSaver System specifically uses a pulse vacuum method for marinating, which vacuums air out of the marinating tray for several minutes, rests for 30 seconds and then resumes air removal once more.

In addition to the vacuum unit, the FoodSaver System also uses a series of sensors to detect conditions inside and outside of the bag. A liquid detection sensor notices when liquid spills out of the top of the bag and automatically shuts the vacuum off. Another sensor detects the presence of a bag and triggers the motor, which starts the vacuum process. When the pressure inside the bag reaches a low level, the machine seals the bag shut using a heating element that fuses each side together.

As complex as the FoodSaver's mechanics sound, the machine is actually quite easy to use. Read the next page to find out how to use the FoodSaver System.

As we've seen, there are two ways to use the FoodSaver System, with bags and with containers with specially-designed lids. We'll take a look at both of these vacuum sealing methods.

It's a easy to vacuum-seal food using bags. A roll of plastic bags -- one long plastic bag, actually -- is stored inside the FoodSaver unit. To create a customized bag, a length of plastic can be pulled out and cut with the bag slicer blade. If it's the first bag off a new roll, the end will be sealed already. If the roll has already been used, the bottom end of the bag will have also already been sealed, since the last sealing will have fused the end on the top of the last bag as well as the bottom of the next one.

Once a foodstuff is put into the bag, the open end can be placed into the vacuum channel, a horizontal slot located at the unit's base. Here, the FoodSaver senses the bag and begins to do its thing. It will shut itself off, but the company recommends using the "Seal" button when vacuum sealing fragile or soft foods like potato chips or angel food cake [source: FoodSaver]. This will cause the machine to seal the bag immediately, rather than continuing to remove air and possibly crushing the chips or smashing the cake. To keep liquids from rising out of the bag and into the drip tray (which will cut the power to the vacuum device), you can freeze the liquid item before placing it in a bag and sealing it in solid form.

The machine also comes with a retractable hose for vacuuming air from things like wine bottles and Mason jars as well as for marinating meats and infusing oils. The hose plugs into the tops of the lids the company sells (some units come with accessory lids, but the hose is only compatible with FoodSaver accessories). As when sealing bags, the FoodSaver hose canister attachment shuts off automatically once the pressure with in the jar or bottle has dropped. Untwisting the hose from the lid seals the lid.

Food isn't the only item that the FoodSaver can keep intact. The company also suggests a number of uses for the vacuum sealer. Live in a flood zone? You can keep paper documents dry indefinitely by sealing them. The same goes for emergency kits for water-logged outings like kayaking trips. It's also a good way to save seeds for gardening between seasons.

Visit the next page for more information on the FoodSaver and related topics.