Post Trip Consumables :Evaluation - use to end of life or replace with new?

I want this thread to be about “consumables” and maximizing their life in ways to realize the full potential of the consumable that is safe and functional.
To define “consumables” let’s start with Websters: “a commodity that is intended to be used up relatively quickly”.
To identify “consumables” (and feel free to add…):
Batteries, fuel canisters, plastic bags, food stuffs… I think you see where I’m going. I want to introduce a thread that shares some “tips and tricks” on using these items, these consumables to their fullest functional (safe) and economic value.
Okay… good but… what happens to a consumable that is not fully expended - has not expired from the last trip?
For example as I pack for a 5 day trip down the Apalachicola river, I run into several (4) fuel canisters. Does anyone have any experience / practice in evaluating the “spent-ness” of the source? Do you weigh it pre-trip and re-weigh it post trip and evaluate and mark it for the next trip?
Ultimate question: How to we maximize the longevity of our consumables and, provide for a safe trip?


1 Like

Much of the food that I take on multi-day trips is freeze dried with a shelf life of years. Any other food gets consumed at home within a few days of the trip.

I might take a package of extra batteries for something I really need to work, like a headlamp, but I don’t actually change batteries until I need to.

The usable contents of isobutane fuel canisters can be estimated pretty closely by floating the canister in water. The higher it floats, the less fuel it contains. I find that one canister will usually serve my needs for a trip lasting up to six days or so so I make sure I start out with a full one. I label my full canisters with a piece of duct tape that has “full” written on it and remove that label the first time I use the canister. I don’t discard partially used canisters. I’m cheap. I use them when base camping until they are fully spent.

I usually take Luci lanterns on trips so battery life is not a consideration there.


You can also switch to a white gas, alcohol or kerosene stove. The only consumable is the fuel and the stoves last indefinitely with very minor maintenance. The same is true of the stoves that use twigs, though finding fuel and controlling the heat can be issues.

Yes float the canister. Some even have marks on the side to show how much is left when you float it. Another way is to put a mark on the canister by scratching with a knife each time you use it. You will soon learn how many marks from your usage it takes to empty the canister. I have used white gas since the 70s. The canisters are convenient, but they generate waste, and in very cold weather don’t work well. The twig/dung/pinecone burners are probably the most eco friendly, but you have to remove the pot to add fuel, they are smoky, and you will benefit from a set of garden clippers to cut dry dead twigs from trees, and 1" dead wood into lengths to fit in the stove.

I use rechargeable AA and AAA batteries in things like headlamps, and gps. I love my Luci lights!

Food is consumed before expiration dates. :rofl:

The most important consumable is … dark chocolate!


My PCP (an MD with a specialty in geriatrics), is very wholistic and keeps continually informed on studies on the best nutritional and exercise regimens, which he practices himself and advises his patients to adopt.

He has determined that 85% dark chocolate has so much going for it in health benefits (like for your heart and immune system) that he “prescribes” eating an ounce of it daily as preferable to NOT eating chocolate at all.

Aldi’s sells packages of Choceur brand five 85% cocoa bars that are about an ounce each, perfect daily ration. Just finished the half bar that I ate as a “palate cleanser” after my supper – the other half was dessert after lunch. I know this is a sacrifice but I grit my teeth and comply.

By the way, the Choceur bars packaging is all cardboard and paper wrappers, no plastic, so I can compost them or put them in the municipal paper recycling bins. For camping, they can be used for firestarting tinder.


I used rechargeable batteries in the gps. I used a solar charger to charge them. Worked OK until I left the charger and batteries on the truck…then went to dinner in Hannibal MO.

1 Like

I would never have to worry about any dark chocolate reaching its expiration date :slight_smile:


I was so disappointed when I found out that Dark Chocolate wasn’t its own food group at the top of a Pyramid or something. That fact alone has made me question the reliability of such rankings.

1 Like

As for gas canisters: as mentioned above, you can get a pretty accurate assessment of amount remaining using a displacement method. You can also transfer gas from one canister to another using a valve like this: G-Works Gas Saver: Canister Fuel Transfer Adapter Review -

I have pretty much stopped using gas canisters. I have a small Solo Stove and I usually use it with a Trangea alcohol burner. I can also burn wood, but its really makes your pots sooty. I carry either a pint or quart fuel bottle depending on how long I will be out. I have mostly rechargeable electronics and have a solar charger and another rechargeable pack to charge with if needed. Since I an normally in a canoe, I have the luxury of a cooler, so I have a mix of fresh meat, eggs and veggies that I prep in advance and augment it with some packaged food, like rice or instant potatoes, salmon and snacks. None ever seems to make it home.

1 Like

Yeah, those disposable iso-pro fuel canisters can be a constant nuisance. All the hostels along the Appalachian trail had hiker boxes with plenty of near-empty cans.

I do start by weighting them. But there’s a little trick I use in the field. I wipe wet fingers along the side of the can. I want just small water droplets all around the metal surface. As the fuel burns and internal pressure drops a fine visible condensation forms on the can. You can see a definitive line showing the liquid level inside the can. The condensation will develop on the upper portion where the internal vapor expands and cools faster. The lower portion (below the condensation line) contains liquid fuel which does not expand. You may need to look closely at the can to see it. Try it with a spray bottle on your BBQ tank while grilling.
It may not be visible on a new/full can, but only after the level drops some. Also consider that the bottom of the canister is concave. So as the level approaches bottom you have liquid fuel just around the perimeter.

I also have a little lantern for those disposable canisters to completely burn off the fuel. Then I puncture the can for the recycle bin. I’m talking about the 4 or 8 oz. iso-butane. I don’t know about those heavier, green, 16oz. propane cans. How do you recycle those???

In deep winter the canisters perform poorly so I switch to white gas stove (Coleman liquid fuel). And I also trust only lithium batteries <35°F. Otherwise rechargeable is OK for 3 season.

Leftover food on a camping trip? Not likely. But just in case that’s why you bring the dog!

1 Like