July 28, 2010

Dehydrating Blueberries: An Experiment

A couple weeks ago, I blogged about our blueberries. I thought the comments were interesting, especially on the topic of dehydrating.  The consensus was that home-dried blueberries end up more like little rocks than raisins.  I know that has certainly been my experience.

I cannot say I am an expert when it comes to dehydrating foods.  I've had some good results and some bad.  The bad have included everything from food that molded to those rocks we mentioned.  I have suspected that there is both an art and science to drying foods, just as there is to baking bread.  Knowledge is certainly required (the science of it), but experience fills in all the gaps that written directions leave wide open (the art.).

After reading all your comments, I took another look at the instruction booklet that came with my dehydrator.  I have an old, 5-tray  Excalibur, which continues to work quite well.  The setting for fruit is 135° F (57° C).  The time table in the booklet allows for quite a range of drying times for berries, anywhere from 10 to 15 hours.  I suspect this variance takes into account the type of berry, its moisture content, and the air's relative humidity.  I can see how each of these would be a factor.  According to the manufacturer, properly dried berries should have a "leathery" texture.  Obviously blueberry "rocks" have been dried too long!

Since I have an abundance of blueberries this year, I decided to experiment.  I decided to dry small batches for each of the recommended times, put them in containers, and observe them throughout the year.


I put a quarter cup of blueberries on each tray, set the temperature gauge to the fruit setting, and timed it.  After 11 hours, I took out the top tray.  I removed the second tray after 12 hours, etc.


The texture of the 11 hour batch was still quite soft, with the berry skins papery.  From my reckoning, they are still too moist.  The 12 hour batch was similar, but the smaller berries were firmer.  The longer the berries were left in the dehydrator, the drier they became, obviously.  In the 14 and 15 hour batches, the smallest blueberries were pretty hard.


Each one has been put in a labeled half-pint jar, and set on a shelf in my pantry.  I will check them from time to time, and give updates on how well they're keeping in my "Around The Homestead" posts.

18 comments:

Geodyne said...

Fabulous. It's always good to approach these things systematically.

Like you, I've found there is an art to drying food, and have had successes and failures. I left my dehydrator in Australia but have been thinking about trying my hand at sun drying this year, as we've been having such a dry sunny summer.

Benita said...

Don't you just love experiments? It's like being a scientist, but the results are more personal than global.

I'll be curious to see what your results are. And I STILL think you should write a book about your experiences as a homesteader.

maggie said...

I love home experiments like this. :) But at my house, they have a tendency to tip slightly toward "mad scientist," or from next door's perspective "deranged neighbor."

Kids and Canning Jars said...

You actually want your blueberries to be rock hard! Did you prick the skins or steam them so the skin could break? Here is a link to my idol in dehydrating. You could not have a better dehydrator. The Excalibur is the best. Good luck watch this video of blueberries it will help I promise!!!
http://www.dehydrate2store.com/videos/?id=5

Melissa

Michelle said...

We store all our home-dehydrated fruit in the freezer to prevent any chance of mold, since we don't use preservative like commercial dried fruit. Then you can stop the drying at whatever texture you prefer!

What Pigs Don't Know said...

Science experiments are right up Jason's alley! Will have to show him this. Looking forward to the results! -Carrie

bspinner said...

I dried blueberries only once and used a screen I took out in the sunshine and fresh air every day and brought them inside at night for what seemed like ages. It's been so long ago I can't remember is I was happy with them or not.

Leigh said...

Geodyne, if we didn't have our humidity, I would love to try sun drying. I think that would be more of an art than a dehydrator though!

Benita, yes, and I'm so glad my readers' comments prompted this. I am thinking about that book. Just need to figure out how to start, what to write, and when to write it!

Maggie, LOL. I know my neighbors think we're weird. Why else would we do so many things around here with hand tools!

Melissa, if that's the case, then all my experimental batches will probably mold. No, I don't do anything to pierce the skins, though I know some folks do. Really, my only argument with last year's batch was that the blueberries were bland and flavorless. They reconstituted well, but weren't tasty. Of course, they weren't very flavorful when fresh, but that wasn't a good year for blueberries. This year there's a huge difference, so maybe drying some of these would be more satisfactory.

Thanks for the link! I'm always looking for good resources.

Michelle, that's an idea. Of course, I'm running out of room in my freezer! really though, I have had good results with home dried fruits and vegetables. Some of them have kept for years. And years!

Carrie, here's hoping they turn out well!

Barb, well they must not have made a huge impression, LOL. OTOH, they obviously weren't absolutely terrible either. You'd probably remember one of those tow things.

Michelle said...

That's why we just bought a 2nd freezer secondhand!

Laura said...

I had a similar experience with blueberries last year. I call them "blue pebbles"! The good news is that they haven't molded... I am still planning to use them, but I think steeping them in brandy before using them in muffins or something would certainly make them more palatable!

I have one of the circular type dehydrators, and it recommends that you rotate the trays every several hours - I would expect that the top trays would be hotter/drier than the lower ones - good thing you took the top one out first!!

Robin said...

What a cool experiment! I have never tried drying blueberries. I plan on picking some more this year but I will probably freeze them again. When we get our kitchen put together then I think drying some would be fun. I would assume that you would use them in a lot of baking? Since I can't really bake at the moment, I just take my frozen blueberries out of the freezer and use them as a snack or whip up some cream and use is as a dessert.

Leigh said...

Oh Michelle, lucky you! Mine seems too small already. Doubt I could talk DH into a 2nd one though as he was skeptical about the first, LOL

Carrie, stay tuned!

Robin, the dried ones are nice for muffins and pancakes. I like your idea of freezing them for snacks and simple desserts though. I've frozen a bunch this year, so I'll be able to try those for myself.

Sharon said...

I don't have home blue berries but the ones from Costco are so sweet that I looked up information and froze ours. I don't have a dehydrator now though I'm trying to get one. My friends in Oregon recommended a Nesco, American Heritage - I think that's it. I'd have to order it online. There are none in stores here - I have exhausted the stores believe me. I used to have one, and along with many things I've lost track of, it's one of them.

Leigh said...

Dehydrators are pricey;! Still, once you have one, you'll be glad you bit the bullet. Of course if you ask me, I'd recommend the Excalibur! :)

Dorothy said...

I am fascinated. I never heard of a food de-hydrator. With one of these I could dry the summer herbs from my garden, going to see if they are available in the UK ...

Look forward to learning how your experiement goes.

patou said...

No, top tray is cooler, had to leave the top one on longer with my red bell peppers.

patou said...

I have 4 Nescos, all bought at thrift shops and swap meets. The one with the heater on top is better. Try ebay if you're impatient.

Leigh said...

I think it depends on the brand of dehydrator and where the heating element is.