Podcast Episode March 12, 2024

Episode 99 | How to Hide Your Food from Bears



In today’s episode of the Backpacking Light podcast we’re going to learn about how bears smell, and what you can do to hide your food from the nose of a bear.
a bear is looking at a bag of food

In this Episode:

What’s New at Backpacking Light?

The Cottage Gear Innovation Awards

the logo for the innovation award

Main Topic: How Bears Smell and What Can You Do About It?

  • The differences between bears being food-motivated vs. food-conditioned vs. habituated to humans.
  • The science behind food conditioning.
  • Comparing the nose of a human, dog, and bear – more olfactory receptors means more odor sensitivity; size of olfactory receptors means more range of smell.
  • By storing foods in a system using plastic ziploc bags, mylar bags, and Nylofume liners, and an Ursack or bear canister, you can reduce the range bears can smell the food down to 0.01% of what it would be originally.
  • Keep the outside of your food bags odor free!

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Home Forums Episode 99 | How to Hide Your Food from Bears

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #3805584
    Backpacking Light


    Locale: Rocky Mountains

    Companion forum thread to: Episode 99 | How to Hide Your Food from Bears

    In episode 99 of the Backpacking Light podcast we’re going to learn about how bears smell, and what you can do to hide your food from the nose of a bear.

    Ryan Jordan


    Locale: Central Rockies

    I’d be interested in knowing what folks do in terms of “cooking hygiene” to keep food smells off the outside of their food storage bags.

    Monte Masterson
    BPL Member


    Locale: Southern Indiana

    I’m also conditioned to stop at In-N-Out Burger for a caloric reward.

    Seriously though, I wasn’t aware Opsacks were that much better than regular Ziplocs. I totally believe it, but Opsacks don’t seem to have much durability. Regardless they’re probably worth the extra expense.

    Mark S
    BPL Member


    I believe there’s a fundamental mistake in the analysis predicting the distance from which a bear can detect the food inside various containers.

    The analysis keys off of the fact that a bear can smell a rotting carcass from 1000 meters away.  The analysis then proceeds to predict a bear’s detection of various containers based on the reduction (in percent) of odor concentration associated with that container system.

    The flaw in reasoning is that we aren’t carrying a rotting carcass. I believe smelly foods were chosen for the example, but a carcass is really big (and probably more stinky unless they’re carrying some of my favorite cheeses).

    Fortunately, the error pushes us towards ultra-conservative which is better than the reverse. Still, I’m often wondering what to do when I’ve just climbed into my bag for the night and I remember the gummy bear wrapper in my pants pocket.

    BPL Member


    Locale: Rainy Pacific Northwest

    I wonder if bears, in their evolutionary history, have developed an olfactory apparatus that mostly zeroes in, especially, and to a very fine degree, on the far-off faint smell of a carcass.
    And I wonder if, upon entering a known human campsite, they simply use their eyes, and being fairly intelligent, simply recognize the obvious food bag or canister, and set themselves to work upon it.
    I use Dr Bronner’s scent free soap with which to wash face, hands, dishes, and brush my teeth.
    I think for a “table” I’ll use a 1.5 ft square piece of plastic sheeting, to be folded up and stored in it’s own ziploc.
    I store rations in their individual ziplocs, each day’s rations in a foodsaver vacuum-sealed bag, all sealed bags stored in a large OPsak, stored in another OPsak, stored in the Ursack, and that stored in a zpacks waterproof food bag, and tie the Ursack in the thickets of the forest, somewhat hidden from an obvious view.  Then when all that is done I cross my fingers.  I’ll check out the Mylar and Nylofume bags.

    BPL Member


    I remember reading a study some years ago (sorry, I cannot say where it might exist) that claimed bears quickly and easily recognize things of a color that isn’t natural, like a yellow stuff sack or a bright orange hang line.  I very rarely camp in bear country, but I immediately swapped out my “unnaturally colored” kit for a neutral “forest colored” kit and have never had a problem :)  I almost always use a PCT bear bag hang.

    BPL Member


    Locale: Northern California

    Yeah…we humans smell. Especially after hiking.  If we cook, the odors  carry. If we light a fire, it’s the same as putting up a huge sign in the sky: humans, and their food, here. Humans  also make a lot of noise and camp within predictable parameters. (Yeah,  I know, camping off trail helps but below alpine levels…a bear will find you. they’d  find you above alpine levels, but there’s no other food there, so bears tend to stay below.) Bears have an incredible sense of smell–beyond that of a Bloodhound.

    I mostly hike in the Sierra. I always assume that,  below 10,00 feet, a bear will find me, if one is in the area. I  al also assume that bears know they can’t get into my canister, and  will move  on looking for easier pickings. And this approach has served me well. The bears understand there’s no food to be had in my camp;  they move on–the next campsite is larger and folks  are careless.

    Nick Garcia
    BPL Member


    Locale: South Florida

    Heading to the JMT in a few weeks, with regards to my BearVault, would you trim a Nylofume bag and use it in the canister or just place the canister inside the bag and twisting the top  when your ready to store away from campsite?

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