Sunday, March 6, 2011

How Not To Dehydrate Yams

(Yes, you read the title correctly)

Yams are a very good source of potassium and fiber, as well as vitamins B1, B6, and C. In addition, yams are a good source of manganese and carbohydrates. Besides all of the reasons they are good for you, they just plain taste great...naturally sweet and full of flavor. I found a recipe for dehydrated yams, and decided it would make a wonderful backpacking meal, so I excitedly went and bought 10 pounds at the grocery store. You get some funny looks when you buy so many yams!

Start by washing the yams, then shred them to whatever size you want. I use the larger size shredding attachment on my food processor for this.

Next they need to be boiled or steamed for just a minute or two. This apparently is a key step because the "cellular membrane within the structure of the vegetable needs to be changed through cooking (like steaming or boiling) so that it’s softer". Skip this step and you'll end up with yams too chewy to be enjoyed. So I brought a huge pot of water to a boil, dropped all 10 pounds of yams in, replaced the cover, and left them in there for about 5 minutes. The volume was so large it really didn't return to a full boil, but I figured it would be OK since I left them in there for longer than a minute or two.

Onto the dehydrator trays the shredded (almost) boiled yams went. 145 degrees until they are crispy - about 5 or 6 hours should do the trick.

What came out was a crunchy little bag of shredded goodness - all 10 pounds fit in a gallon bag. They taste pretty good right out of the bag too!

So how did they come out once a cooked them? Chewy...too chewy to enjoy. Obviously that step where I didn't bring them back to a full boil was more important than I thought. So rather than toss them, I reboiled them, then dehydrated them again. This time when I cooked the yams they were not chewy, but I think the repeated boiling, dehydrating, boiling, and dehydrating cooked the wonderful taste right out of them. They were bland.

So this post is about what NOT to do...we all make mistakes. I'm going to try this again, and I will boil less yams at a time and make sure I bring them to a full boil. Yams are too good to give up on, so wish me luck and I'll let you know how it goes!

Update 3/06/2011: My second attempt was a great success...sooo good! As Eugene suggested below, add some butter flavoring, cinnamon, or whatever you prefer to make it even better. And a huge advantage is the fact that it ends up being extremely light. Today I started with 27 ounces of yams and after dehydrating the batch weighs scant 3.08 ounces, which translates to 281 calories per ounce. This is the most calorie dense food I have found, even higher than 257 calorie per ounce almonds! Have some of both and you end up with a great balance of carbohydrates, fat, and protein!


  1. Nice! I can see a butter packet, some brown sugar, cinnamon, and a dash of nutmeg going pretty far in that dish.

  2. When in the field - I add a pre-made sauce of peanut butter, hot sauce and vinegar! Amazing.

    Also - When I prepare em, I use a pressure cooker, and "steam" the shredded yams for just about 30 second. Then I drink the orange water at the bottom of the pot. YUM!

  3. Mr Clelland, I'm flattered to have you visit my site...I'm a big fan of your work! Your Groovy-Biotic Cooking article on BPL was the inspiration for this post, and I will definitely be trying your sauce idea.

    Since I don't have a pressure cooker, I found that bringing the yams to a full boil did the trick, but a pressure cooker is on my wish list.

    Thanks for your comment!

  4. Oh yum...I really like the Satay/PB sauce. I make that and add it to Ramen and top it with some wild onions/scallions, but to add your satay sauce to dehydrated/rehydrated Sweet Potato..WOW! that sounds AMAZING!

  5. Cook and mash the sweet potatoes. spread on teflon or parchment to one eighth inch thick and dehydrate. Break up dried pieces and grind into powder. Ten pounds of powder will fit into a quart ziplock. Rehydrate starting at a 2 parts hot water to one part powder simmer. Add more water if necessary. You can also add the powder to soups or stews.

  6. To retain the vitamins, steam them instead of boiling. Unfortunately vitamin C is destroyed by heat.

  7. I love your posts! Great ideas. However, I don't think your calorie calculation is correct. An ounce is 28.3495 grams. The most calorie dense food is pure fat, which is 9 calories per gram. 28.3495 g/oz * 9 cal/g = 255 calories/ounce. Sweet potatoes would be mostly starch and carbs are slightly less than half half the calories of fat, so pure starch with 0% water would be 125 calories/ounce. These would be maximum caloric values/wt but since some water is present, actual calories would be slightly less. Some calories must be lost along the way. Perhaps a lot of starch is washing into the water?

    Again, I love your ideas and I bought a dehydrator just to start making some Delight Sauce! :)