If you have a good machine, such as our winning countertop model, the Nesco Deluxe Vacuum Sealer ($90), vacuum sealing food is quick and easy. Here’s how they work: Vacuum sealers typically come with a starter set of plastic bags, after which you buy more separately. You place the food you want to seal inside the bag, taking care to keep the top of the bag clean because food reside can prevent the bag from sealing tightly. Next, open the machine’s lid and position the bag. It goes over the seal bar and inside a small chamber ringed by a foam gasket. Shut the lid and press or lock it into place following the manufacturer’s directions. A port inside the machine pulls air from the bag and the seal bar heats up and melts a narrow strip across the top of the bag, sealing it shut. If you follow that basic method, plus our tips below, your food will last much longer than it will in conventional zipperlock bags or storage containers.
1. Label First
It’s hard to write neatly on a bag full of food. Instead, label your bags before you fill and seal them.
2. Use the Right Size Bag
Any food residue on the top of the bag can prevent it from sealing properly, so be sure to choose or cut a bag with enough room to get the food inside neatly. For most foods, 2 to 3 inches of headroom is sufficient.
3. Cuff Bags Before Filling
To keep the part of the bag that will be heat‑sealed clean before filling, fold the top 2 inches over to form a cuff; uncuff the bag before sealing it.
4. Make Bags Flat and Stackable
Bags that are flat stack better and save space. Both for food storage and sous vide cooking, arrange food so that it’s flat before you seal it.
5. Partially Freeze Fragile Food
To avoid crushing fragile foods such as fish and fresh berries, place filled, unsealed bags in the freezer for a couple hours. When the items are firm, vacuum-seal the bag.
6. Seal Only What You Want to Use at One Time
Freeze small amounts, only what you’ll want to thaw or cook at one time, in each bag.
7. Freeze Liquids Before Sealing
A vacuum sealer can pull liquid into the machine as the bag compresses, making a mess and potentially causing damage. To avoid this, freeze liquids until they solidify before vacuum-sealing them.
8. Include All Ingredients
When sealing bags to freeze for future sous vide cooking, be sure to include all ingredients, such as oil, butter, stock, and any herbs and spices. That way you can drop the bag straight from the freezer into the hot water bath without having to open, season, and rebag the items before cooking.