Drying / Dehydrating

Introduction: Drying / Dehydrating

About: Made in Canada, I grew up crafting, making, and baking. Out of this love for designing and creating, I pursued a BFA in product design from Parsons School of Design in NYC. Since then I've done work for Martha…

Drying/Dehydrating is the oldest form of food preservation. From prehistoric to modern times, humans have used the heat from the sun, fanned by fresh air, to dry everything from mushrooms to fruit to herbs to seeds for planting the following season.

While it has always been an option in hot, dry climates, the advent of dehydrators (primitive to electric) have made drying and dehydrating foods for later consumption accessible and so easy!

In this chapter, we'll look at how we can adapt this ancient technique at home to properly air dry herbs and use a (not so ancient) dehydrator to make fruit leather and dried tomatoes.

Step 1: Why This Method Works

Like us, both enzymes and the spoiler microorganisms need water. Without it, they can't survive and won't thrive. While dried foods do still contain a bit of moisture - from 2-10% depending on what it is - as long as the foods are properly stored, it isn't enough water content to support the growth of spoilers. (Take that Salmonellae!)

It's also recommended to steam-blanch vegetables before drying. I know this seems counterintuitive, exposing something to water before drying it out, but it works like it did in the freezing chapter to slow enzymatic action and help the veggies retain vitamins during the drying process. It also helps keep their colors bright!

The only difference from the freezing chapter is that they should be steam-blanched instead of dipped in boiling water. Vegetables require longer blanching times in order to stop the enzymatic action that spoils low acid foods and they would get too waterlogged if we used the boiling water method.

Step 2: Supplies

These are the supplies you'll need if you decide to try the types of drying / dehydrating and suggested projects I link to in this lesson:

For Air Dried Herbs


For Fruit Leather

  • dehydrator (or oven)
  • fruit leather dehydrator sheets (or parchment and spray on oil)
  • ripe fruit*
  • lemons
  • cutting board
  • paring knife
  • chef's knife
  • medium bowl
  • small bowl
  • citrus juicer
  • blender
  • measuring cup
  • measuring spoon
  • colander

*Apricots, peaches, plums, berries, apples, pears and grapes can all be used by themselves or mixed with one another. Yum!


  • craft wood as spacers**
  • craft wood as leveler**
  • masking tape**

**These are used for a little system I made to get my leather to be a uniform thickness. Check it out in the fruit leather step! Similar wood strips are available at art supply or hardware stores.

For Dried Tomatoes

  • dehydrator
  • tomatoes
  • cutting board
  • paring knife
  • chef's knife
  • colander
  • large bowl
  • vinegar

Step 3: What (and What Not) to Dehydrate

As with all forms of preservation, there are foods that are better suited to this method than others.

An important warning to mention about what you shouldn't dry/dehydrate before we get to what you should:

NEVER HOME DRY eggs, poultry, and meat (except for very lean meat that is being made into jerky). These foods are a favorite of Salmonella and Staphylococcus bacteria. It's not worth the risk. Leave these to the commercial professionals.

Now, onto a sample list of wonderful things to dry at home. Remember to only use food that is in prime condition, aka very fresh*, as for all forms of food preservation.


  • pears
  • peaches
  • cherries
  • apples**
  • apricots
  • prunes
  • nectarines
  • coconut
  • dates
  • berries
  • bananas
  • blueberries***

*I do like my fruit to be on the ripe side of fresh for fruit leather because I find that produces a more flavorful product.

**In order for apples not to turn brown (aka oxidize) during the prepping and drying process, sprinkle a solution of 3 teaspoons ascorbic acid dissolved in 1 cup water over the pieces as you peel, pit, core and slice them. Peaches, apricots, pears, and nectarines also benefit from this practice.

NOTE: There are certain fruits that have a natural wax-like coating on them that need to be 'checked' in order to properly dehydrate. This means removing the coating by blanching them for 10 seconds and then plunging the fruit immediately into cold water. The fruit, other than blueberries, that require checking are: cherries, figs, grapes, prunes, dark plums and huckleberries.


Vegetables are less commonly dehydrated, but there are a few that work well with this process.

  • chili peppers
  • tomatoes
  • sweet potatoes
  • sweet corn
  • some herbs
  • mushrooms

*If you have more veggies to add to this list, please send me a note!

Step 4: Project #1: Air-Drying Herbs

The first suggested project for this lesson is: Air-Drying Herbs. This is the simplest drying/dehydrating method, as it require almost no tools – and NO ENERGY – to make happen. The air itself draws the moisture out and dries the herbs.

This technique is only safe to use on things (like herbs) that have very little moisture in them to start. If you tried to air dry a tomato slice (for example), due to its high moisture content, the spoilers would take hold and it would mold before the air had a chance to do any significant good.

To try your hand at my instructable on air-drying herbs, click on the link below.

How to Dry Herbs

Step 5: Using a Dehydrator or Oven to Remove Moisture

If you plan on doing a fair amount of dehydrating, I highly recommend investing in a good quality electric dehydrator. It doesn't have to be the fanciest on the market, but things to look out for are:

  • metal racks (if you're concerned about warm/hot food touching plastic like I am)
  • a side mounted fan* instead of a bottom mounted fan

*A side mounted fan more evenly distributes the air to all racks so that you don't have to shuffle the racks throughout the drying process.

Using an Oven Instead

If you'd rather try out these recipes to see if you like the results before investing, not to worry! The oven will work just fine, but will require some extra attention during the drying process.

The dehydrating processes can take anywhere from 6-24 hours (depending on what you're drying) and most home ovens don't have low enough settings to replicate the dehydrator settings, so you end up having to use (and monitor) an oven thermometer and attempt to keep the temp low enough by turning the oven off and on repeatedly, so that it doesn't over heat the foodstuffs. But it IS possible and a good way to start out if that's the only resource you have.

If you are lucky enough to have a convection setting on your oven, always use that for dehydrating, as the air flow created cuts down the oven drying times by almost half.

Step 6: Project #2: Fruit Leather

Fruit leather is a personal favorite. And PEAR fruit leather is at the top of my leather favorites list, so that's the recipe I chose to share.

To experience the tasty magic that is homemade fruit sheets of dried goodness, while practicing yet another method of food preservation, try my fruit leather instructable (link below).

Homemade Fruit Leather

Step 7: Project #3: Sun-Dried Tomatoes

The final project suggestion for this lesson is sun-dried tomatoes. Well, FAUX sun-dried tomatoes really.

Instead of battling humidity, insects, and morning dew – challenges that come with drying things outside – I find it easier to dry tomatoes indoors where they're less likely to mold before enough moisture has been removed. (Remember: The more moisture present, the higher chances that spoilers will grow!)

And not to worry, the results of home-dried tomatoes are just as delicious and 'Italy inducing' as the traditional sun-dried versions. :D

To give these tasty tidbits a try, click my instructable link below:

Sun-Dried Tomatoes

Step 8: Storage Tips

Place all dried/dehydrated foods in airtight containers, label/date them and store in a cool, dry, dark place like a cupboard or pantry. As long as moisture doesn't get introduced into the containers, the dried foods should last indefinitely!

Step 9: To the Pantry and Beyond!

Congratulations! You've completed my class on Canning & Preserving. I'm proud of you and hope you've enjoyed learning the basics of home food preservation. I'm excited for all the year round deliciousness in your future! :D

Here's some ideas of how to further your preserving craft:

  • Try new recipes using different fruits and vegetables! I've handpicked some great instructables for you to try once you've mastered the ones in this class. See the bottom of the class page for links.
  • Tackle pressure canning. It will allow you to can all the low acid foods that weren't invited to our high acid boiling water bath canning party. The book 'Putting Food By' is a deep dive into all things preserving, including how to pressure can.
  • Build your own outdoor solar dehydrator?

Just a few more of the ways to keep your pantry, fridge and freezer stocked with home preserved foods! :D

Try My Fresh Pasta Making Class!

If you enjoyed this class and want to learn more ways to play with food, check out my pasta making class and learn how to make delicious fresh homemade noodles and accompanying sauces.

Class Feedback

Please let me know what you thought of this class by sending me a message via my Instructables member profile page. If you have any suggestions on ways I can improve it, I want to hear about them!

Thanks & Happy Making!


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