by Jay Ham | 2005-03-15 03:00:00-07
AntiGravityGear Pot Cozys are available to fit a wide variety of popular cookpots (and custom sized Cozys are also available). This one is sized to fit a 1.3-liter EverNew Titanium pot.
AntiGravityGear Pot Cozys have found their way into the packs of several staff members at Backpacking Light. Inserting a hot cookpot into a Cozy keeps food warm longer and can extend cooking times without further fuel consumption. We know we like them, but the unanswered question is "how much difference do they make?" To find out, I boiled 0.5 liter of water and measured temperature drop over time in a cookpot with and without a Cozy. I repeated the tests in freezing and room temperature conditions, using my ideal hot tea temperature (132 °F) for comparison. The AntiGravityGear Pot Cozy more than doubled the amount of time water temperature remained above 132 °F under sub-freezing (28 °F) conditions. The Cozy weighs less than 1.5 ounces (40 g) and, depending on your stove and fuel of choice, its weight may be justified by fuel savings and/or added convenience.
• Product ID
|AntiGravityGear Pot Cozy sized to fit a 1.3-liter EverNew titanium pot|
|Reflectix insulating wrap (1.25 oz/ft2)|
|1.3 oz (37 g) as confirmed by Backpacking Light|
|$9.00 (Price differs with different sized Cozys.)|
The AntiGravityGear Pot Cozys are made from Reflectix insulation, consisting of two bubble wrap layers sandwiched between layers of aluminum foil bonded to polyethylene. This material is designed to insulate heating ducts and hot water heaters, and its light weight renders it ideal for insulating cookpots for the lightweight backpacker. The aluminum reflective material makes the insulation more durable, heat resistant, and insulating than bubble wrap alone.
While it's true the Cozy keeps food warm longer, I carry mine to allow me to carry less fuel. After cooking for a shortened period of time, the cookpot is removed from the stove and placed inside the Cozy. The Cozy lid is then placed on top of the pot's lid, and the edges of the Cozy are folded inward to seal the top. Food continues to cook at the higher temperatures maintained inside the Cozy. It is important to understand that the pot must be removed from the stove and placed in the Cozy - never place the Cozy on the stove; it melts!
In practice, it is difficult to determine how much fuel is saved with a Cozy, because cooking time depends on several variables: the quantity and type of food, cooking temperature, ambient temperature, wind speed, and water temperature. I always leave behind more than enough fuel weight (alcohol) to justify carrying the Cozy, and have fuel remaining at the end of the trip.
For this review, a 1.3-liter EverNew titanium cookpot was paired with an appropriately sized AntiGravityGear Pot Cozy. The cookpot was filled with 0.5 liter of water (approximately 2 cups). After bringing the water to boiling (201 °F at 7,200 feet elevation), the pot was removed from the stove and temperature was recorded every 10 minutes under four conditions:
Temperature was measured using a digital kitchen thermometer with a remote sensor fit into the pour groove of the EverNew pot, allowing the lid to close securely. Room temperature varied throughout the study from 75 °F to 80 °F, while freezer temperature was constant at 28 °F.
For our discussion, we could select any temperature as a base line to compare results between the different tests. Ideally, this would be a real world temperature; like the minimum temperature to cook pasta, a typical backcountry staple. Cooking professionals seem to agree, however, that pasta is best cooked at a rolling boil, and a minimum pasta cooking temperature cannot be found in culinary literature. I settled instead on using my ideal hot tea temperature of 132 °F as a base line to compare heat retention performance.
The graph below shows temperature along the Y-axis and time along the X-axis. As expected, water cooled fastest in the uninsulated pot under freezing conditions; temperature stayed above 132 °F for less than 20 minutes. Using the Cozy under freezing conditions, the temperature remained above 132 °F for approximately 45 minutes. At room temperature, the uninsulated pot stayed above 132 °F for approximately 55 minutes, and the insulated pot kept water above 132 °F for 90 minutes.
Change in Temperature Over Time
Temperature drop in freezing and room temperature conditions with and without an AntiGravityGear Pot Cozy.
The Pot Cozy improved heat retention 2.3 times under freezing conditions and 1.6 times at room temperature. The insulated pot performed nearly as well under freezing conditions as an uninsulated pot at room temperature, allowing the winter backpacker to mimic three-season cooking. These results will likely differ somewhat from field conditions where wind and other factors come into play. The type and amount of food cooked and the type of cookpot (titanium, aluminum, stainless) will make a difference in how well heat is retained. Nevertheless, these results clearly show that a Pot Cozy extends cooking time and heat retention thus saving fuel.
Weight savings from fuel will depend on the type of fuel and stove efficiency. Certainly, those who prefer the extremely low end-of-trip weight of an alcohol or fuel tablet stove will benefit greatly from fuel reductions earlier in the trip. Fuel savings from a few dinners may offset the Pot Cozy weight. Esbit tablets cost about 50 cents each, so a Pot Cozy will eventually pay for itself if used long enough. With canister stoves, where there is less control over the amount of fuel carried, it may not be feasible to reap the benefit of reduced fuel consumption. The benefits of a Cozy used in conjunction with a white gas stove will be more noticeable in terms of the convenience of not having to simmer and being able to melt snow while your dinner is cooking.
"AntiGravityGear Pot Cozy REVIEW," by Jay Ham. BackpackingLight.com (ISSN 1537-0364).
http://backpackinglight.com/cgi-bin/backpackinglight/antigravitygear_pot_cozy_review.html, 2005-03-15 03:00:00-07.