Last fall, while bowhunting elk miles from the nearest road, I ate like a king without ever striking a match. Instead of my bulky stove and cooking pots, I used a new flameless cooking pouch made by MealSpec, and enjoyed hot, nutritious food twice a day.

The MealSpec pouch is one of a number of new portable cooking products that uses the reaction of chemicals to heat water that then cooks food. I also tested products from MagicCook and Barocook, comparing their portability, ease of use, field utility, and intensity and duration of heat. The latter two products (above, right) are virtually identical—both use chemical pouches in conjunction with supplied cooking vessels, which makes them easy to use but limits their portability and capacity.

The MealSpec product has a wider application in survival, military, and backcountry situations, or for anyone who needs lightweight and compact cooking gear that deploys quickly and relatively cleanly.

The Science
These flameless cooking products function like chemical hand warmers. Those packs use iron filings as their fuel and a salt compound as their catalyst. When exposed to humid air, the salt compound rusts the iron, producing heat as a byproduct of the exothermic oxidation.

The fuel in MealSpec pouches is aluminum powder, which reacts with calcium oxide when water is introduced and produces a more intense heat. In the case of the MealSpec, the heat is contained in a vented, zip-top bag that allows steam to escape but retains the hot water. I managed to get the temperature of the water in my bags up to 215 degrees on average, and they maintained at least 170 degrees for nearly an hour. That’s enough heat to sterilize water, hard-boil an egg, or warm up any prepared food that fits in the 11-by-13-inch bag.

The Utility
I used the MealSpec bag mainly to heat up dehydrated foods. I mixed cold water with the dried food, then sealed the food bag and placed it in the MealSpec bag. Then I added water (precisely 6 ounces) to the outer bag, zipped it up, and waited 20 to 25 minutes for my food to warm up.

According to MealSpec founder and CEO Dave Huselton, the military is looking at this single-use pouch to replace the standard MRE (Meal Ready to Eat) because of its portability and reliability, and for its ability to cook a variety of foods. “You can poach an egg, cook a raw chicken breast, or cook the fish you just caught,” notes Huselton. “That means you don’t have to carry your food. You can cook whatever you find or catch.”