You may already know that Outdoor Herbivore is against the use of heating foods inside of soft plastic. It doesn’t align with our view of producing backpacking food made from high quality, organic ingredients, and subsequently urging hikers to pour boiling water inside a plastic bag to reconstitute it. This is why we do not sell our food in stand-up cook pouches.
But cooking liners are rated for much higher temperatures (up to 400 degrees F), so does that make them safer for hot food?
Out of curiosity, we decided to look at the feasibility of using cooking liners as an alternative to reconstituting hot foods in cooking pouches.
What are Cooking Bag Liners
Cooking bags, or pot liners, are essentially a smaller version of a “turkey” bag, such as those designed to trap moisture while cooking a turkey inside of an oven. The only difference is that the cooking bag liners are sized to fit inside of a round pot so that foods can be boiled and simmered inside. Because the liner eliminates food-to-metal contact, it prevents sticking and keeps your dish clean.
Cooking bags are made of high-temperature synthetic plastic polymers (PET or nylon), which are thin and flexible. The bags, while extremely thin (about 1 millimeter), are made from the same material to withstand cooking for several hours inside of a hot oven.
How Cooking Bag Liners Work
You insert the bag inside of your cooking pot so that it nests inside of your pot while you boil water and cook/reconstitute dried meals. Since food never makes contact with the metal wall of your pot, it eliminates any food particles from sticking there. While you don’t have to worry about cleaning your pot, you will have to carry the dirty liner until you can find a trash receptacle to dispose of it properly.
Here is a video showing cooking bags in action with a backpacking stove:
Cooking Bags for Backpacking
Pot liners can be an alternative for backpackers who like the convenience of cook pouches or freezer bag cooking. The added advantage of using a liner is that you can eat directly from your pot, which likely has a wider opening than a rectangular shaped pouch/freezer bag. Besides giving you more space to dig in and eat, the bowl shape makes it easier to scoop out every last drop, eliminating food from getting caught in a corner. Otherwise, the advantages of a liner are similar to a pouch –
- Saves on dishwater & eliminates clean-up work since food does not make direct contact with the cook pot.
- Frees up the cooking pot for the next immediate use; however, you must lift out the bag and be careful not to spill the contents as there is no top seal.
Advantages of cook liners
Unique advantage and disadvantages of cooking liners over traditional plastic backpacking food pouches rated for boiling water.
- High-temperature rating (up to 400 degrees F); however, upon closer examination the 400-degree rating is for radiant heat, not direct contact with heat.
- Uses less plastic (1 – 1.5 mil) when compared to cooking pouches (5 – 8 mil) which means they are lighter to carry and cheaper to produce.
- Eliminates the need to use of a separate insulated “bag cozy” for keeping food hot while it is rehydrating in a plastic pouch. With a liner, the food rehydrates inside of your lidded cooking pot, which is a much better insulator.
- Easier to eat from versus a cooking pouch with corners. The liner takes the shape of your cooking pot (bowl) since it nests inside of your pot, thus giving you more room to dig in and eat.
Disadvantages of cook liners
- 1-time use; high temperatures cause the plastic to break down after initial use.
- Works best for radiant heat; direct heat can cause melting. During our tests, 60% of the bags we tested melted from normal use.
- If the liners do melt while you are cooking food, not only will you have a mess to clean up, but you will have ruined your meal with the melted liner.
- Must get the right size liner to prevent excess plastic from hanging over the edge, which can melt to the side of your pot with stove flame and create a mess.
- Food residue can still get caught inside the corners or wrinkles of the bag. This means you are packing out cooked food waste as well as dirty packaging.
- The liners are very thin and can get cut with spork or fork during stirring.
- The risk you assume from eating food heated inside of plastic (non-BPA does not guarantee safety).
Until cooking bags are suited for direct heat, we don’t think a 60% failure rate is a good investment for avoiding dishes. Some manufacturers suggest adding water to the pot before placing the liner inside, which can protect it from the melting created by hot spots that may develop from direct heat. We did not try this extra step. Another suggestion is to not use the liner for boiling water/cooking, but only for hydrating the food. At some point, you have to ask yourself if the extra expense is worth the perceived benefits. For us, liners created an additional hassle.
Cooking liners come in various sizes. The smallest standard size is a 2 Qt round liner (9″ x 14″), which is large enough to fit major backpacking cook pots, ranging from 1 – 2 L in size, including the common brands such as, GSI, SnowPeak, MSR, and JetBoil.
The cost for an individual pot liner ranges from $.12 – $.40.