PDA

View Full Version : Dehydrating foods and having them KEEP



ScottP
02-19-2008, 01:09
This year I plan to dehydrate my own fruits and vegetables. I also plan to make my own energy bars. I bought a vacuum sealer as well as a dehydrator, and since I sweat a lot when I hike, all of my food will be amply salted.

Does anyone have any tips on getting dried fruits, beans, vegetables, etc. to keep?

My two energy bar ideas:
#1 Home-made skim yogurt (done this before, it works well), mix in nuts, dried fruit, salt, and instant 12-grain oatmeal, spread onto sheets and dehydrate, vacuum seal

#2 instant quinoa flakes, some home-made almond butter (to hold everything together), salt, and dehydrated vegetable chunks.
dehydrate, vacuum seal.

I know that the #2 bars won't taste the greatest, but I'm really more worried about nutrition and about the food that I prepare and package now keeping until I finish my hiking season at the end of August.


Thanks,

Hermes

ScottP
02-19-2008, 01:11
Additional question: would it be possible to use whole milk instead of skim, and still have the energy bars keep?

Appalachian Tater
02-19-2008, 01:12
Some people keep their dehydrated food frozen until it is mailed to them.

minnesotasmith
02-19-2008, 01:30
I suggest these options instead:

Cooked meals:
Add dried parsley, dried tomatoes, or dried onion (all easy to get, often from dollar stores)
Buy freeze-dried spinach and broccoli in quantity online (Emergency Essentials is a seller I've used), and add it to Knorr's whole-grain mixes, ideally ones that already contain some green vegetables

Uncooked trail food:
Sushi-grade (black-colored and preferably Japanese-origin) seaweed -- has protein and minerals as well as vitamins
Germans sell a cooked vegetable sausage that might be worth getting as well

Town food:
Make a beeline for the canned goods section, and get 1-2 cans of dark green vegetables to eat with every nonrestaurant meal; that means spinach, kale, collards, turnip greens, asparagus, or peas, NOT cabbage, celery, green beans, wax beans, or starches like corn or potatoes

Restaurants, try to hit AYCEs like Golden Corral, Shoney's, Ryan's, Western Sizzler, or Ponderosa (all at non-breakfast times), where you can get ready-to-eat decent vegetables in quantity. (Add brussel sprouts to the list of good veggies, but avoid the raw green peas on the salad bar, along with lettuce of any kind.) Chinese food tends to be greasy, and hamburger/hotdog/fried chicken place? Leave those for the hikers less serious about getting to put their hand on the sign on Mt. Katahdin. ;)

Dogwood
02-19-2008, 07:10
ScottP, like the yogurt energy bars idea. Where do U get the quinoa flakes? U kinda lost me on the quinoa energy bars when u added the veggies though. I'm new to dehydrating myself, but I wonder if U can reuse or purchase those sealed packets that absorb oxygen(a company called Ageless makes them) that U find in store bought prepackaged dehydrated foods. Maybe, those would help your dehydrated food to last longer? It's funny I read your concerns about food keeping because just tonite I was repackaging meals for the PCT and was concerned that I wouldn't be using some of this food until 2-3 months down the road(trail). I just double baggied most of it until it's ready to be mailed and when I repackaged it I tried to squeeze as much of the air out as I could.

minnesotasmith
02-19-2008, 08:05
They do not work in the presence of dessicants. The latter deactivate the former over time.

Also, O2 absorbers reduce gas volume in containers. This will create negative pressure that can bring in air and water, especially if the container is nonsturdy AND nonflexible. (Bags and to some extent plastic softdrink/juice bottles will collapse, desirably.)

fiddlehead
02-19-2008, 08:34
If it's any help, i found some hamburger that i had dried in my pack 5 months after the hike and it was still ok. I just ziplock and put in the freezer and the only thing i ever had go bad was cheese (parmesan)

I usually buy in season or grow my own and dry veggies as the stuff you buy out of season has no taste. wait till they get tree ripened for peaches. They are awesome on the trail then. (of course it is too late for that now unless you are here in the tropics and don't buy from one of the bigger growers who somehow can grow food that has no taste)
Don't dry bananas too hard, they taste much better if you don't.

Don't know about the milk question but would think the whole (fat) milk would be tough to dehydrate. Fat doesn't dry. (to my knowledge) You can buy powdered fat milk in Mexico and France though so there must be a way. I've seen a thread on that on whiteblaze a few years ago i think. Milkman brand (dried) milk isn't bad if you must buy it in the states.

budforester
02-19-2008, 08:55
Does anyone have any tips on getting dried fruits, beans, vegetables, etc. to keep?
I'm really more worried about nutrition and about the food that I prepare and package now keeping until I finish my hiking season at the end of August.


Thanks,

Hermes
As said, the freezer is a good storage place. Tips: be sure it is adequately dried; protect from moisture, oxygen, light.

Dehydrated foods will keep a long time. Most of the vitamin losses have occurred by the time the food is dry; there is little more lost over time. With good storage the minerals, carbs, fats, proteins are fairly stable.

budforester
02-19-2008, 09:04
Additional question: would it be possible to use whole milk instead of skim, and still have the energy bars keep?

You could probably get it to ferment OK, but I suspect it would dehydrate better without the fat content. Also, milkfat may be more prone to oxidative off- flavors... there is probably a reason that yogurts and cheeses are often made from skim- milk. BTW, I sometimes make yogurt from non- fat dry milk powder; it's cheap and I can mix some up and start a batch whenever I want, from that fresh box in the pantry.

Fiddleback
02-19-2008, 09:50
Is there really a problem?

The original point of drying foods was to 'keep' them through the seasons they weren't available...and they were kept without refrigeration. Dehydration takes the drying process a little further and, IMO, extends the shelf life of the food even longer. Refrigerating/freezing the food until it's time to hit the trail should help but keeping the food protected from air and bugs on the trail is probably more important. Use care to not introduce pathogens into the package by repeatedly dipping into it with dirty hands, utensils, etc, and your properly dried/dehydrated food should last much longer than your hiking season.

As for powdered whole fat milk -- Nido can be found in the ethnic food section of WalMart and I've read that other brands are available at REI.

Test the food at home and have fun!

FB

Alligator
02-19-2008, 10:08
...
Does anyone have any tips on getting dried fruits, beans, vegetables, etc. to keep?...
Vacuum pack and freeze. I don't usually do fruits, but all my meals are combinations of veggies, beans, and grains. I've used meals up to 2 years old. That's not rigorously tested, but I think you would be fine for meals of these types up to a year. There are three things you have done to the food: dried, vacuum sealed, and frozen it. The problem is, your meal is usually different than others so that storage times will be hard to really know for sure. Your kitchen is not a well controlled environment.

You are going to dehydrate your energy bars? Have you actually tried one after this process?

Smile
02-19-2008, 11:36
I've dried a bunch of shrimp and added little mini sealed packets to some pasta meals, they need to be rehydrated first while the water's heating up, and then continue while the pasta cooks. A few of the bags desealed for about a week, but they were still very rock hard and crunchy, so I just resealed them again, and all is well with the new seal ( I tried cheap bags, not a good idea, stick with the FoodSaver brand bags!) I don't think - but don't know - if any regular moisture in the air that got in could over a short time ( say within 6 mos) would be enough to do anything to the shrimp.

Any ideas or experience with this?

budforester
02-19-2008, 12:14
I've dried a bunch of shrimp and added little mini sealed packets to some pasta meals, they need to be rehydrated first while the water's heating up, and then continue while the pasta cooks. A few of the bags desealed for about a week, but they were still very rock hard and crunchy, so I just resealed them again, and all is well with the new seal ( I tried cheap bags, not a good idea, stick with the FoodSaver brand bags!) I don't think - but don't know - if any regular moisture in the air that got in could over a short time ( say within 6 mos) would be enough to do anything to the shrimp.

Any ideas or experience with this?

Moisture absorption could accelerate development of off- flavors. Microbial spoilage in an almost- dry food would usually show up as mold growth.

ScottP
02-19-2008, 12:22
Thanks for the advice everyone.

I won't be able to store these in a the freezer (my mom is doing my maildrops and she really won't have the storage space for 4-5 months worth of hiking food)

I've tried the oatmeal yogurt bars. They taste better than power bars, but not as good as clif bars.

Hoop
02-19-2008, 13:34
About to buy a dehydrator -- any recommendations, or is anyone dissatisfied with their choice?

Smile
02-19-2008, 13:36
Excalibur. :)

fiddlehead
02-19-2008, 23:38
Here's the only picture i have of mine. BUilt it myself, inside there are 6 (aprox) 1.5 foot by 1.5 foot trays made from wooden frames and teflon screening.
I bought the heater that sits in the bottom. The top slides open for air control. http://i249.photobucket.com/albums/gg201/fiddleheadpa/zdehyrator.jpg

I've supplied lots of my hikes with this dehyrator and the beauty of it is that it is so big.
I've lived on organic farms out west where they just spread screening out in the heat and put thousands of peaches, apples, whatever on them to dry.
Also saw people who just stretch screening above their woodburners in winter to dry veggies.
I use my oven for the hamburger.

minnesotasmith
02-19-2008, 23:44
Is an appropriate-sized freeze-dryer that's not intended for laboratory use, so is halfway reasonably priced.

Wise Old Owl
02-20-2008, 00:49
Additional question: would it be possible to use whole milk instead of skim, and still have the energy bars keep?


If I had to guess how to do this in my house I would take regular yogurt add some honey and DRIED Milk to the mixture in blender Then add the rest of it and pulse the other ingredients in. Then take the plastic sheets for making Fruit rollups and spray nonstick and spread the mixture and turn on the dryer.

You are in a test and trial area,

budforester
02-20-2008, 12:01
Is an appropriate-sized freeze-dryer that's not intended for laboratory use, so is halfway reasonably priced.
That's a difficult wish, but you might contact a local dealer in used food processing equipment. They have wide connections and can come up with unusual items, sometimes. You might try DIY, too. Here's a wikki link (http://en.wikipedia.org/wiki/Freeze_drying#Freeze-drying_equipment)about the process. Foods are usually processed on trays, for maximizing surface area. I have frozen them in a conventional deep- freeze. Then one needs to place the trays in a chamber and suck down vacuum past the critical point quick enough to avoid any thawing... want the water to go straight from solid to vapor. So you need a very good vacuum pump and a chilled trap to keep moisture out of the pump. A vacuum chamber with a good seal is needed. I wonder if a discarded pressure vessel like an autoclave could be fitted up. Then the process can be speeded by raising the temperature... you could do this at room temperature, it would take longer. You might find equipment ads in trade magazines or contact food science staff in you local universities for some sources of used equipment... maybe someone could even be talked into doing some trial batches for you. I no longer have the connections to do that.

Mercy
02-20-2008, 13:12
I bought a 700 watt Nesco online from Target after looking for weeks in various stores.
$69.95 I had it in a couple of days (about a week earlier than what the tracking system at Target said!)

Make sure the one you get has a fan (I've used a friend's that doesn't, and there's no comparison!)

I like mine because 1)it is pretty quick 2)it has five nice sized trays 3)it came with 2 screens and 2 fruit roll up trays 4)you can add more trays later if you want 5)its easier to clean than the one I'd borrowed from my friend.

Pedaling Fool
02-20-2008, 13:48
I bought a 700 watt Nesco online from Target after looking for weeks in various stores.
$69.95 I had it in a couple of days (about a week earlier than what the tracking system at Target said!)

Make sure the one you get has a fan (I've used a friend's that doesn't, and there's no comparison!)

I like mine because 1)it is pretty quick 2)it has five nice sized trays 3)it came with 2 screens and 2 fruit roll up trays 4)you can add more trays later if you want 5)its easier to clean than the one I'd borrowed from my friend.
Fans are crucial, carries away the moisture saturated air, otherwise you might as well use the oven.

Pedaling Fool
02-20-2008, 13:58
I've never done anything special to keep my food while waiting to be mailed off. This includes meat/poultry, fruits and vegetables, all of which I've kept for about a year at the longest. I just store in a plastic bag (regular ziplocks, not vacuum sealed) and throw in my mail-drop box. Would not subject my dehydrated food to light, especially sunlight, not sure if that would be bad, just seems like the right thing to do.

The Weasel
02-20-2008, 14:03
Three things that help make dried foods last:

(1) Eliminate or don't add anything with fat, to the greatest extent possible. "Whole" milk if very fatty, and fat gets rancid with age, anywhere from a few days (in very warm temps) to a few weeks or so, sometimes longer, but rarely.

(2) Especially for meats/poultry/fish, use significant amounts of black pepper and garlic powder, which retard spoilage significantly.

(3) Eliminate all air to the greatest extent possible, either by vacuum or at least by tight packaging. If drying using an oven or warm dehydrator and ziplocs, pack while warm in a warm room, then seal tightly, and freeze/refrigerate until needed.

TW

Pedaling Fool
02-20-2008, 14:11
Fat is a problem, because it doesn't dehydrate. Never dehydrated anything with milk in it. Although I've done tons of meat/poultry. When I make the marinade I add about 1 tsp of salt to each pound of meat. I heat the marinade to disolve the salt then put the meat in once marinade has cooled. I let soak (all meat is soaked) over night then dehydrate. DISCLAIMER: I never cook poultry, despite many things I've read directs cooking. So take your chances, has worked fine for me.

The Weasel
02-20-2008, 14:23
Fat is a problem, because it doesn't dehydrate. Never dehydrated anything with milk in it. Although I've done tons of meat/poultry. When I make the marinade I add about 1 tsp of salt to each pound of meat. I heat the marinade to disolve the salt then put the meat in once marinade has cooled. I let soak (all meat is soaked) over night then dehydrate. DISCLAIMER: I never cook poultry, despite many things I've read directs cooking. So take your chances, has worked fine for me.

Salt is excellent. A shortcut that includes pepper, vinegar and salt is to use a few tablespoons of Worcestershire Sauce per pound of meat.

TW

Cuffs
02-20-2008, 14:39
Excalibur. :)

Thats for sure! I love mine!

As for the addition of salt... why? You say its because you sweat alot. Sweat, while not too attractive, is a good thing. I know the sodium promotes water retention, but you need to sweat to keep you cooled off to some extent. Its a natural body function, dont fight it.

ScottP
02-20-2008, 14:42
Hydration requires more than just water--it also requires electrolytes (salt is one of these).

Having a ton of water and not enough salt is just as bad as having not enough water!

minnesotasmith
02-20-2008, 14:49
Hydration requires more than just water--it also requires electrolytes (salt is one of these).

Having a ton of water and not enough salt is just as bad as having not enough water!

1) Most hikers have plenty of sodium in their bodies and normal diet anyway.

2) Trail food commonly has if anything substantially more salt in it than food hikers eat back at home.

3) Only a few elite athletes doing faster-paced (say, running) exercise in hot, humid weather are commonly at risk for hyponatria, which is a life-threatening depressed level of sodium in their bodies/bloodstream.

4) From first-hand experience in exercise in hot weather (I lived in the tropics while on a cross-country running team that ran in the daytime only, aside from summer AT hiking) while adding no additional salt to my food, I never have had an apparent problem with low sodium levels in my body.

Thus, instead of worrying about how to get enough salt into your body when hiking in warm weather, I'd suggest looking at it as a welcome way to dump excess salt already in your body, that you won't want to do anything intentional to replenish it.

Alligator
02-20-2008, 15:17
1) Most hikers have plenty of sodium in their bodies and normal diet anyway.

2) Trail food commonly has if anything substantially more salt in it than food hikers eat back at home.

...I don't normally add any salt to my food while cooking. I found once on a longer trip in hot conditions that I was very likely salt deficient as a result of not adding any salt to my meals. All my dinners were home dehydrated. I can't remember all the snacks from that trip, but I remember including unsalted sunflower seeds in my GORP.

It was clearly obvious that a lot of the salt that I had going in to the hike had left. I judged this from the whitening of my backpack.

Most folks do get enough salt, but be careful of being overly cautious also.

Pedaling Fool
02-20-2008, 15:33
...Most folks do get enough salt, but be careful of being overly cautious also.
It is a balancing act. I try and listen to my body (I know sounds whaky) but when you focus on what you need vice what you want it actually can work. Not easy though, takes some practice, since our lifestyle is centered so much on what we want.

ScottP
02-20-2008, 15:35
Cross the desert in June then tell me how much salt I need to bring to cross another desert...or talk to any ranger in the grand canyon, and ask them how common evacuations because of hyponatramia are.

Every PCT hiker learns very quickly to carry some form of salt supplement.

Hiking 35+ miles a day carrying a pack up and down mountains in a desert is an elite athletic activity and has requirements beyond what someone running cross country (3.1 miles) will have.

When buying pre-made food, there is often an excess of salt. When making your own food, it is very important to make sure that you have some salt in everything, AND an additional way to regulate salt intake (salty pretzels, one hiker even carried a salt lick, etc.)

sarbar
02-20-2008, 16:04
Scott...I live on a low sodium diet and still hike in hot areas and yes, I sweat quite well. I also enjoy section hiking the PCT every year, and yes, enjoy reasonably long miles per day.

But...it isn't the salt you need. It is a balanced act - and one thing you really need is potassium. Often the foods we crave contain a bang of potassium as well as salt (such as potato chips, mashed potatoes and french fries).

The majority of hikers out hiking are not doing even 20 miles a day - more like 10 or less. Those few doing 20-30 or more, well, yes, they are different. But you cannot say that every hiker needs a ton of salt. They just don't with a normal American diet. On average most Americans are consuming 3-5,000 mg of sodium a day. We don't need that! We can live on 1500 mg a day quite easily - if you balance everything. I rarely break 2300 mg a day when backpacking. (I don't feel like laying on my mat listening to my heart race all night after a salt fest.)

What I have learned over the past couple years on meds and many Dr's later is this: if I eat something saltier than I should (ie...over 150 mg of sodium per serving) I make sure I eat something high in potassium with it (such as OJ, banana, potatoes, greens, etc). This helps my body process the sodium. I don't retain fluids and it helps with my heart. I try to keep dinner under 800 mg, and always have vegetables in my dinners.

While high endurance athletes do require more, just remember it isn't only salt you need! You need potassium and other electrolytes! They balance water retention and help your heart be protected. You strip your potassium and you will have MAJOR issues. What many don't realize is that when your electrolytes are stripped it affects your ability to think clearly, you will feel lethargic and sleepy as well.

Better to carry lots of vegetables and fruits, eat a balanced diet of carbs and protein and if you get a craving, well pay heed to it.

Mercy
02-20-2008, 16:08
I coat my meats with lime juice first, then add whatever I'm marinating in, then dehydrate. For many years I was on a boat with ice only... no freezer. I can tell you that lemon or lime marinated meats took much longer to spoil. (The lime also makes the meat more tender)

ie. I preserve with lime rather than salt.

I eat my jerky as a protein source, not to add salt to my diet, therefore, my jerky isn't real salty. (I sure like that smoked flavor, though...)

ScottP
02-20-2008, 16:50
I know that I tend to consume plenty of water and potassium, but not enough salt (even at home when I'm very active I need to actively add salt to my food or else I wake up in the morning with calf cramps). I don't have the typical American diet where salt is added to every food, and I rarely eat pre-processed items, so for me making sure that I have enough salt is an issue. I eat a large amount of fruit and vegetables, so I have never had potassium problems.
I had similar issues (but far worse), on my AT shakedown of my food system last year. I had enough of everything BUT salt. I was hiking with Li, who is a ranger in the Grand Canyon and an experienced desert hiker, and he told me that based on my diet and his past experiences (including frequent evacuations for hyponatremic hikers in the grand canyon), that my salt intake was too low. After adding some salt to my diet, I had no more problems. Again, as I said, not an issue for people consuming pre-processed items, but something to keep in mind when preparing your own food. I never said 'hikers need to eat more salt.' I just said that I know I need to add salt to my food. I am making no recommendations to other hikers about nutrition.
I also wrote above that salt is just one electrolyte to keep in mind. Again, I have the salt/electrolyte/water thing figured out pretty well for myself and don't really need input from anyone unless they feel that they are an expert on the topic.

The issue at hand isn't proper hydration, it's how to keep dehydrated foods from spoiling. Salt relates to the spoilage question in that it should extend the shelf-life of my foods.

Appalachian Tater
02-20-2008, 16:58
The basic issues, then, are:
1. Achieve proper dehydration by removing sufficient water to prevent spoilage; then
2. Maintain a sufficiently-dehydrated state to prevent spoilage.

You already know how to keep moisture out of foot. Seal it in an airtight container and use desiccants if necessary. Salt is a safe, inexpensive, common one.

sarbar
02-20-2008, 17:37
to keep dehydrated foods from spoiling. Salt relates to the spoilage question in that it should extend the shelf-life of my foods.

Well, yes and no. To properly store food it is air and moisture that are your enemies. First off, make sure the food is 100% dry, let cool then package in food vac bags. If you want a better seal get a commercial food sealer instead, they work a lot better. Use a dessicant in your packages that is food grade.

Salt was used for a long time in preservation as it does work - but at a cost of taste. Of course, back in the day salt was also hard to come by so using it in meat wasn't a bad idea. We can do so much better these days though.

In all honesty, I would only recommend salt in preserving food when it comes to jerky (which is using the old methods used for thousands of years anyways). In everything else you just can do it with heat and packaging. Even in the olden days salt was used only in preservation of meat and cheese. Vegetables, fruits and grain have always been preserved by drying. They don't need to be salted.

Nearly Normal
02-20-2008, 17:38
Buy the How to books or check at the library.

hopefulhiker
02-20-2008, 18:35
Had a problem with some of the homemade beef jerky molding a little bit after sending it to sit in Post officess.. It was just stored in ziplocks.. but the problem was soved by...

I found that if you vacuum pack the dehydrated food with one of those machines they sell at Wal Mart, then freeze t the food will last longer..

budforester
02-25-2008, 20:45
Is an appropriate-sized freeze-dryer that's not intended for laboratory use, so is halfway reasonably priced.

MS, in a post today, Gumball gave a source for some freeze dried products. Here's a link (http://www.whiteblaze.net/forum/showpost.php?p=549924&postcount=10). they have quite a variety and offer bulk sizes. They even have some "organic" products. It might be cheaper and easier to formulate meals from prepared ingredients... that's how food manufacturers operate.

Wise Old Owl
02-29-2008, 14:52
I've dried a bunch of shrimp and added little mini sealed packets to some pasta meals, they need to be rehydrated first while the water's heating up, and then continue while the pasta cooks. A few of the bags desealed for about a week, but they were still very rock hard and crunchy, so I just resealed them again, and all is well with the new seal ( I tried cheap bags, not a good idea, stick with the FoodSaver brand bags!) I don't think - but don't know - if any regular moisture in the air that got in could over a short time ( say within 6 mos) would be enough to do anything to the shrimp.

Any ideas or experience with this?

Yes, I too have had the premium bags deseal and air get back in, but you do not need to rebag them they are ok even with hot water in them I suspect the hole where the air got in is not an issue. I am not sure about dried shrimp after 6 months.

On another tread I am working on a project of dried and regular spam in both freezer bag and vacume seal a meal. I was surprised at how much water was in spam. some of it is going in the dryer and all of it will be kept at 70 degrees to test shelf life from 3 to 7 days.

Wise Old Owl
02-29-2008, 14:58
I bought a 700 watt Nesco online from Target after looking for weeks in various stores.
$69.95 I had it in a couple of days (about a week earlier than what the tracking system at Target said!)

Make sure the one you get has a fan (I've used a friend's that doesn't, and there's no comparison!)

I like mine because 1)it is pretty quick 2)it has five nice sized trays 3)it came with 2 screens and 2 fruit roll up trays 4)you can add more trays later if you want 5)its easier to clean than the one I'd borrowed from my friend.

Uhh I am not going to argue here, I recieved a Ronco With extra trays and it doesn't have a fan, When I added a fan for fun it took longer. I like it just the way it is. Funny how I got a different result.