A lot of people say they like the Old Faithful Flameless Geyser Portable Cooking System but that it is too heavy for backpacking.

You can still have all the speed and convenience of flameless cooking without the weight. I’m going to show you a hack that allows you to use the Old Faithful Geyser technology, a freezer bag, and a collapsible water bottle for lightweight cooking and heating water at the same time. This Ziploc Freezer Bag method can also be used to heat up to four MRE 8 ounce entrees at once or a double portion Mountain House freeze-dried meal without the water bottle. Basically, anything you can fit into the freezer bag and seal shut upright can be heated. Trail cooking doesn’t get any easier than this.

You will need:

Old Faithful Flameless Geyser heating pack

01-Gallon Ziploc Freezer Bag

Mountain House single serving freeze-dried meal

01-liter collapsible water bottle

 Step 1:

Open the Mountain House meal and add ¾ cup of water from your one-liter collapsible water bottle. Squeeze some air out of the bag and seal the zip top shut. Knead or gently shake the bag a little to distribute the water throughout the dry ingredients.

 Step 2:

Open one Old Faithful Flameless Geyser heating pack and put it in the bottom of a dry 01-Gallon Ziploc Freezer Bag.

 Step 3:

Place the Mountain House meal in the bag. Squeeze the excess air from your water bottle and seal it. Place the one-liter collapsible water bottle into the bag with the meal. Arrange the contents so that the heater pack is on the bottom of the bag and can contact the meal and water bottle.

Step 4:

Add 6-8 ounces of water to the Ziploc bag to activate the heater pack.

Step 5:

Seal the Ziploc bag and cut a ½ inch slit in the bag near the zipper closure to vent steam. If the slit isn’t large enough the bag will pop open.

Step 6:

Prop the bag against something to keep it from falling over while it cooks. You may need to put a rock or heavy stick on each side to keep it steady.

That’s it! The heater pack will start to steam in one minute. Allow the bag to cook for 15-20 minutes. CAUTION: The Ziploc bag will get very hot! DO NOT try to move the bag while cooking.

So how did it work? During a field test, the Mountain House meal was nice and hot. The water was hot enough to make some instant coffee or tea.

Performance test results:

Outside air temperature: 40F

Water bottle temperature at start 60F

Water bottle and food temperature at finish 172F

If you dry out the Ziploc Freezer Bag it can be used again if you are careful with it. The Old Faithful Flameless Geyser heating pack can be safely disposed of in the next trashcan.