Insulated lunch bags are essential for keeping food at its peak and safeguarding against variances in temperature that can lead to food safety concerns. With proper insulation, your lunch will stay hot or cold for hours at a time. While many lunch bags today come with an insulated material built right into the lining of the bag, many bags still lack any kind of insulating material whatsoever. If you are looking to increase the insulating properties of your lunch sack, there are a few simple tactics you can try.
Visit your local craft and fabric store to order insulated fabric. Generally sold in 54 inch widths and featuring a silvery, reflective material, this insulating material will help to regulate the temperature of your meal. Depending on the size of your lunch bag, you may simply be able to stuff a length of this fabric into your lunch bag and cut to fit, with no sewing required. Bring the bag with you to the store and the sales staff can assist you with determining how much fabric you need to order.
Pre-chill the lunch bag and all food storage containers in the freezer. This will help to keep cold foods chilled more than if you use the bag and containers at room temperature.
Fill any empty space in the lunch sack with ice packs to prevent further loss of heat.
Freeze foods strategically. Frozen berries, grapes or juice boxes help to keep the rest of your lunch cold, and will thaw by the time you are ready to eat lunch.
Supplement your bag's insulation properties with the fabric discussed in Step 1, Section 1 above.
Search for creative heating solutions. You probably already have a hot water bottle or a heating pad for pain relief in your home, and these can provide additional heat for the foods in your lunch bag.
Purchase 1/2 inch styrofoam from your local craft store, and cut it to fit the bottom and top of your lunch bag. Styrofoam has moderate insulating capabilities, so it will help your food to retain heat.
Select food storage containers that are already insulated to store within your lunch bag, such as a Thermos.