Freeze Drying · Prepping · Preserving · Recipes

Freeze-Drying versus Dehydrating: Frozen Peas and Corn

We have been running comparisons with Freeze-Drying versus Dehydrating with various ingredients, to see what the outcome is. This has meant that we are running both our Harvest Right freeze-dryer and our dehydrator running nearly non-stop of late. We have the large size Harvest Right freeze-dryer for reference.

This post is on drying frozen petite peas and sweet corn. Both are blanched, so pre-cooked. It’s as easy as taking a bag out of the freezer and processing it. No hard work doing any prep this time.

Freeze-dried on the left, dehydrated on the right.

Dehydrated on the left, freeze-dried on the right.

Now then….what is the actual difference between dehydrating it, versus freeze-drying it? In each method I weighed out the frozen product in both ounces/pounds and grams, measured it in cups, and then after cooking it, and then after it was dried.

Dehydrating Frozen Green Peas:

  • Frozen weight – 16 ounces / 454 grams
  • Frozen measurement – 3¾ cups
  • Dehydrated weight – 3.2 ounces / 90 grams
  • Dehydrated measurement – ¾ cup + 2 Tbsp

Placed on 3 dehydrator trays, dried at 153° for about 4 hours, till fully dry. Let cool on counter, then weighed and packaged up.

Freeze-drying Frozen Green Peas:

  • Frozen weight – 16 ounces / 454 grams
  • Frozen measurement – 3¾ cups
  • Dehydrated weight – 2.9 ounces / 82 grams
  • Dehydrated measurement – 2¼ cups freeze-dried

Place frozen on freeze-dryer trays, lined with silicone mats. Put into the machine, which was set on the pre-freeze mode. Took 18 hours 36 minutes to run batch. Processed immediately upon being done, into glass mason jar and sealed to remove air.

Dehydrating Frozen Corn:

  • Frozen weight – 16 ounces / 454 grams
  • Frozen measurement – 3 cups
  • Dehydrated weight – 4.9 ounces / 137 grams
  • Dehydrated measurement – 1¼ cups

Placed on 3 dehydrator trays, dried at 153° for about 4 hours, till fully dry. Let cool on counter, then weighed and packaged up.

Freeze-drying Frozen Corn:

  • Frozen weight – 16 ounces / 454 grams
  • Frozen measurement – 3 cups
  • Dehydrated weight – 4 ounces / 113 grams
  • Dehydrated measurement – 2 cups freeze-dried

Place frozen on freeze-dryer trays, lined with silicone mats. Put into the machine, which was set on the pre-freeze mode. Took 18 hours 36 minutes to run batch. Processed immediately upon being done, into glass mason jar and sealed to remove air.

Rehydrating:

We broke down the weight to what was ¼ pound when fresh. This way it was equal even though the size of the product wasn’t. We weighed by grams, converted to ounces, and then measured in a dry measuring cup.

Freeze-dried on the left, dehydrated on the right. As you can see, the dehydrated is much smaller in appearance. The color gets more intense as well.

However, you can only eat the freeze-dried in a dry state. The dehydrated needs to be soaked to be edible.

Freeze-dried on the left, dehydrated on the right.

Each item was weighed and measured out into a bowl. I covered each item with boiled water, stirred it, and covered it for 10 minutes. Checked for visual appearance, and taste/texture. Then let sit for another 5 minutes, for a total of 15 minutes.

  • Dehydrated Peas – 1.2 ounces dry equals 4 ounces fresh.
  • Freeze-dried Peas – 0.7 ounces dry equals 4 ounces fresh.
  • Dehydrated Corn – 1.2 ounces dry equals 4 ounces fresh.
  • Freeze-dried Corn – 1.0 ounce dry equals 4 ounces fresh.

Dehydrated left, freeze-dried right.

Both were tasty, but the dehydrated had some issues. About half the peas were perfect looking, but others were still small, as if their cells had collapsed. Still tasty, but would shine best in a soup.

Dehydrated left, freeze-dried right.

The freeze-dried are plump and look no different than before they were dried. The dehydrated though, have the look of dent corn, and while they taste good, they are just too chewy.

The Takeaway:

  • Dehydrating is the fastest way.
  • Dehydrating is the cheapest way.
  • Dehydrating frozen (cooked) vegetables leaves the final product very small. In the case of the peas, nearly 3 cups of water was dehydrated away.
  • The color of dehydrated gets more intense than freeze-dried (which often the color becomes very light when dry).
  • Freeze-drying preserves the size of the vegetable. It will be usually about the same size as when frozen.
  • Freeze-dried allows immediate eating, as a crunchy snack.
  • Dehydrating requires soaking to be edible for vegetables.
  • Freeze-dried rehydrated 1/3 faster than dehydrated.
  • The texture of both the peas and corn when dehydrated is “leathery”. This has always been an issue as long as people have been drying food for the outdoors and storage. When I first started writing backpacking recipes long ago, green peas were one of the few splurges I did for freeze-dried. If the dehydrated food isn’t fully hydrated, your stomach will grind on it. It’s why I use dehydrated veggies usually only in soups and stews, where it has a long time to plump up.
  • For long-term storage, if properly sealed, freeze-dried can last up to 25 years. Dehydrated is 1 to 2 years for storage. It will often become tougher and harder to rehydrate as it ages.

The Winner:

Freeze-drying wins with frozen vegetables. Yes, it is not the cheapest, nor the fastest method. But it produces a far superior product. Eating freeze-dried green peas is a real treat. They are crunchy, airy, and sweet as can be. They can be enjoyed as a snack, and as an ingredient in so many meals.

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FTC Disclaimer: This post contains affiliate links that give us commissions on products purchased. These items are what we used in the recipe/method above.

~Sarah