DIY Freeze Dry and Dehydrator
Backpacking Food Tip #2: DIY Freeze Dry and Dehydrator
Most of the shelf backpacking foods tend to fall into two categories: dehydrated or freeze-dried. Either way, the water has been effectively removed from the food, making it less dense (lighter weight) and sometimes significantly smaller (depending on the food). So, water-less food is the way to go, standard operating procedure, for most backpackers and backpacking trips. While I prefer fresh food, every trip is going to involve something that I need to add water too, but usually from the store, like a pudding mix or red beans and rice mix (I’ll talk about them later, no doubt). So, the real topic here is getting away from the prepackaged backpacking foods that are, unfortunately, quite expensive, by using a DIY method.
Today’s entry is the DIY Freeze Dry and DIY Dehydrator. If you have these two skills, you can literally bring anything into the wilderness with you and make it lighter and more compact from the magic of water loss. So, whatever your cooking or packing skills are, pick up these home skills as needed.
So we’ll use chili as an example. Chili is delicious on the trail, and you can usually find some dehydrated boxes of chili beans and spices in the supermarket. What these lack are three things: water, tomato paste, and meat. (If you’re a vegetarian, bear with me. You can do this with tofu or the fake ground beef substitute in the veggie section by the produce. It’s just an exercise.) Those chili kits serve four on the trail nicely. A particularly good one is called Darn Good Chili, and it is. Divvy it in half for a duo. It does leave you a little bit hungry though, so you want to add meat or make some biscuits (that will come later too). We’re going the meat chili route.
If you were making this at home, you’d probably pick up a pound of chuck and a can of tomato paste for the chili kit. The pound of chuck in my store is going for about $4.00 a pound, rounding up. It’s heavy and bulky, so chuck is not a good trail option. Cans also are horrible to deal with in the back country – you have to clean them, and stow them, and they don’t get smaller. Backpackers often seek out the rarer alternate form of tomato paste in a tube, because it’s less messy and lighter (usually). The tubes in the supermarket are rather gourmet, so I will turn to a neutral but like minded source for pricing, the General Grocery page at Packit Gourmet, who makes food kits for food lovers. I like their schtick, but they are pricey.
At Packit Gourmet, I can get 2 oz of freeze dried ground beef for $9.99, which turns into 4 oz when rehydrated. I can also get a tube of paste for $4.99. The meat is pretty much a single person’s serving. That means, to rock my trail group’s socks off, I would need to buy four orders of 2 oz to get a full pound of meat, and spend $39.96 to do it. Meanwhile, the can of tomato paste I can get for $1.50, probably cheaper if I shop around. The ones on the shelf are usually 6-8 oz, and the tube stuff really isn’t that much more concentrated and is about 4.5 oz – they sort of equal out, so don’t worry.
So priced as such, I’d spend $44.95 for the backpacking versions verses $5.50 for the regular stuff. In my book, that’s just not cool. Ah, but what about the time and effort you say? Does that make up for it? Not really. Pick a day when you have some time at home, like to do laundry, or an evening where it’s an at home movie night, and your time is spent doing fun things and not watching the water leave your food. Not that laundry is as fun as a movie, but you get my drift, right?
DIY Freeze Dry
Dry ice at supermarkets and some other supply stores generally costs only $1 a pound. All you need is a cooler, and some left over plastic containers – or even ziploc freezer bags. It takes a couple of days, but if you try not to open the cooler, it works just fine.
You need about an equivalent amount of dry ice to your food, so here we need one pound to freeze dry our chuck. You can get more if you want to be sure. It works by sublimation, the process by which water turns directly into vapor without heating up to that silly steam phase of existence.
First cook the chuck and let it cool. Protect the chuck from the dry ice by using the freezer bags or layer it with it in the plastic containers using paper plates (it won’t stick to the paper). If you use the plastic, poke some holes. The whole point is to give the water an exit and let the dry ice vapor do it’s magic. Make sure the chuck is spread out into chunks so it will fall apart easily after freeze-drying.
Pop that into a cooler for a few days – you may need to crack it open every so often to let the vapor out (or put a towel under the lid to prop it open). Over time, the water will sublimate and leave the chuck behind. This can take several days, so you can pull out a test “bite” to see how it reacts when thawed. It should be shelf stable and somewhat hard/soft (not one way or the other). It won’t turn black or react with air, but it will rehydrate in water and regain it’s springy chuck-like qualities. Food-like qualities.
Bottom line: It might take some experimentation, but you can pretty much throw dry-ice and food into a cooler and get dehydrated food.
Dehydrators are also expensive, but at least dehydrated food is cheaper than freeze dried food (see any $1 rice-a-roni sale). There are a lot of DIY backpackers who very much insist on getting a machine to do this, but I bet you already have one. It’s called an oven.
Like with the DIY Freeze Drier, you need a place for water vapor to go, so you’ll need a towel or potholder to prop open your oven door, which makes this a great winter time or evening activity. Turn your oven on it’s lowest setting, usually 150-200 degrees F, put the food you wish to dehydrate in the oven on a tray, put the towel in the door (turn off your oven light if you can, here, or it may stay on) and leave your food alone for hours. Here’s what to do for our tomato paste:
High amounts of surface area is key for the water vapor to escape the paste, so you can’t just pop in an opened can. It won’t work. Get some parchment paper because it will peel off easily from that, $3. Cover your tray or a cookie sheet, or pan or whatever with a layer of parchment. Spread your paste over the parchment with a spoon or spatula so it’s thin as possible.
I like making “columns” so I can divide the paste up if I need to. Only need half the can for a recipe? Maybe you’re only a duo and only need half the chili? Or maybe you need some other arcane fraction for a recipe in the future? Lay out your paste accordingly. Divvy it into sections – one quarter in a square here, or halves. Leave a little bit of blank parchment in between and you have an easy way to visually divide your paste.
Pop the tray into your low-setting towel-doored oven. If your oven can do this, set it to Convect. It helps circulate out the vapor. Check it in about two hours, and you will see the progress. You can touch it at this point and feel the progress too. Little droplets of water will be forming on top of the paste – the paste will be sweating it out. It usually takes about 3 or 4 hours to do tomato paste, which is great for dinner-and-a-movie night at home. When you’re done for the night, take the tray out, and see if the paste has stopped sweating. It might still be a little sticky, but it should not be moist. You can let it dry on the counter overnight and just go to bed. That’s it.
Bottom line: A little prep-time, a towel, and your favorite James Bond movie combine to make packable tomato jerky.
Alternate method: This is a little dangerous with more liquid foods, and very dangerous with sticky foods, and I don’t think I would ever chance it in our Mustang, Grace, but you can indeed dehydrate your foods on the dashboard of a car. It’s like a little greenhouse. Just crack your windows and put your tray on your dash. I kid you not. The kids at our school made fruit leather that way. It takes all (school) day, but it’s brilliant. Dudes, are you listening? YOU CAN USE YOUR CAR. IT’S DUDE FOOD. (I’m looking at you, Quinn!)
So there it is. If you have a little time and want to expand your trail recipes, or just want to lighten the recipes you have, you can very easily put together a DIY Dehydrator or a DIY Freeze Drier. See what seems to fit your style best, or what you want to try. The DIY Dehydrator is a little more sure fire the first time around, but the bottom, bottom line is this:
Why should I spend $40 more for food I can alter in my own kitchen while watching Pierce Brosnan find yet another way for Sean Bean to die on screen like I did last night???
(That and playing with dry ice with gloves makes me feel like a mad scientist. You?)
Cheers, and happy eating!