Quickly and Easily Preserve Produce with Flash Freezing

One of the challenges with eating seasonally is that when food ripens, an overload sometimes occurs. Consider the amount of zucchini you are offered between June and August. There are boxes at church, piles at work, neighbors leaving them on your doorstep – and if you have a garden full of them, well, God bless you, because you are a busy person, picking day and night!

Thankfully, it’s actually easy to preserve garden produce for later use.

(Posts on Under the Median contain affiliate links. When you make a purchase through one of our links, I will receive a small commission at no additional charge to you. To read our affiliate policies, click here. Thank you.)


There are really three ways to significantly lengthen the shelf-life of foods: Dehydrating, Canning, and Freezing.


Canning requires an investment in jars, lids, a canner, and various other optional pieces of equipment. I must admit, with the exception of applesauce, I’ve not done much canning (nor did I enjoy the experience very much).


Dehydrating allows you to store more items, while using less space. You can use a commercial dehydrator. I have a nine-tray Excalibur. This top-of-the-line unit gives you incredible versatility and a lot of rack space!

If you aren’t in the market for a commercial dehydrator, then you can use your oven or even your microwave to dehydrate. The microwave works especially well for dehydrating herbs.


For step-by-step freezer organization instructions, watch this video from our YouTube channel.

Some fruits and vegetables lend themselves better to freezing than others. The list of what really should never be frozen is actually pretty small. Celery loses cell structure when frozen. It’s a limp mess when you try to thaw and use it. However, celery leaves can be dehydrated and of the entire plant can quite successfully be cut into small pieces and dehydrated. The higher the water content, the less likely it is to freeze well.

Some Items Which Don’t Freeze Well

  • Radishes
  • Potatoes
  • Lettuce
  • Cucumbers
  • Melon
  • Citrus fruits

Freezing Methods

When it comes to cold storage, it is necessary that you understand two things: Which foods require blanching and which ones can be directly frozen. After that, it’s simply a matter of deciding whether you need the item stored flat, shredded, or frozen into large, ready-to-use cubes. I use the large ice cube method mainly for freezing herbs. Zucchini lends itself well to shredding and then freezing in quart bags, with 2-4 cups of product per bag.

For a list of common fruits and vegetables, their shelf life, and methods of long-term storage, request my free fruit and vegetable savings guide.

The final method of freezing is flash freezing.

What is Flash Freezing?

Flash freezing involves laying the produce in a single layer on a baking sheet and then freezing until solid. The items are then removed and placed in a labeled freezer bag for long-term storage. The main advantage of this method of freezing is that when you open the bag, you can easily remove just the amount that you need for your recipe, since each single fruit or vegetable was individually frozen and then packaged.

Before Beginning

It’s very important that you first find out if the item you wish to freeze needs to be blanched. Blanching is when you boil a vegetable for a short time and then remove it, thrusting it into a cold water bath to stop the cooking action. Blanching inactivates enzymes which are responsible for rotting the produce. It also helps preserve the color and consistency of the produce once it is frozen.

A good rule of thumb for vegetables with bright color, like broccoli, is to take them out of the boiling water when they turn bright green. The texture when you thaw it will be perfect and the color will be retained.

Some Vegetables Which Need to be Blanched

  • Green Beans – (3-5 minutes)
  • Broccoli – (3 minutes)
  • Asparagus – (2-4 minutes depending on the thickness of the spear).
  • Peas – (2 minutes)
  • Squash – (3-5 minutes)
  • Corn – (4 minutes)
  • Cauliflower – (5 minutes)

For a list of the most common vegetables and methods of lengthening their shelf life, request a free copy of my Fruit and Vegetable Savings Guide

Step-by-Step Flash Freezing Guide

Step 1:  Cut the fruit or vegetable into the size that you will most likely want to use. 

Some fruit, like strawberries or grapes, is perfectly fine to leave whole.  For instance, I slice green onions into small pieces, while zucchini is sliced into pieces appropriate for soup or for a casserole. 

Step 2: Line a baking sheet with parchment paper

 The parchment paper keeps the fruit or vegetable from sticking to the surface of the baking sheet.

Step 3: Place the entire baking sheet flat into your freezer. 

Depending on the size, thickness, and water content of the fruit or vegetable, it will take between 20 and 45 minutes for the individual pieces to freeze firmly.

Step 4:  Remove the tray from the freezer

The parchment paper can be shaped into a funnel to allow you to easily transfer the contents of the pan to a large freezer bag.

Step 5:  Prep the Freezer Bag for Proper Storage

Remove as much air as possible from the freezer bag.  Label with the month and date of freezing, the name of the item, and (if applicable) the amount which is in the bag. 

2 thoughts on “Quickly and Easily Preserve Produce with Flash Freezing”

  1. Sorry but this is not flash freezing

    In physics and chemistry, flash freezing is the process whereby objects are frozen in just a few hours by subjecting them to cryogenic temperatures, or through direct contact with liquid nitrogen at −196 °C (−320.8 °F). It is commonly used in the food industry.

    • In the scientific arena, you are correct. However, the terminology is also commonly used in relation to home cooks freezing produce in a single layer on a baking sheet. Thanks for your comment.


Leave a Comment