How to Freeze Dry Green Beans at Home

Freeze drying, also known as lyophilization, is a great way to preserve foods like green beans while maintaining their flavor, texture, color and nutritional content. With the right equipment and techniques, you can easily freeze dry green beans at home.

An Overview of Freeze Drying

Freeze drying works by freezing foods and then reducing the surrounding pressure to allow the frozen water in the food to sublimate – transition directly from solid to vapor form. This sublimation happens because the frozen foods are kept under vacuum conditions. The final product retains 98% of its nutrients and is extremely lightweight because of the removed water content.

When done properly, freeze drying also prevents the growth of microorganisms and slows down chemical reactions that cause food spoilage. This allows freeze dried items to be stored for years if kept dry and sealed from humidity.

Benefits of Freeze Dried Green Beans

There are several advantages to freeze drying green beans yourself at home:

• Long shelf life – Properly freeze dried and stored green beans can last 5-25 years depending on the storage method. This gives you access to their flavor year-round.

• Lightweight – The water is removed during freeze drying, making the end product very lightweight and easy to store.

• Nutrient retention – Unlike other preservation methods, freeze drying retains 98% of the original nutrients in green beans. This includes vitamins minerals and antioxidants.

• Intense flavor – With the water content removed, the natural flavors of the green beans become concentrated and intense. Rehydrated freeze dried beans taste fresh.

• Easy to use – Freeze dried green beans can be directly rehydrated by soaking in water or adding to soups, stews and other dishes. No thawing required.

• Food safety – The very low moisture environment inhibits bacterial growth, mold and microorganisms that cause food spoilage.

Equipment Needed

You’ll need the following equipment to get set up for freeze drying green beans at home:

• Freeze dryer machine – This specialty appliance is required for freeze drying. Look for models with temperature controls and a collector for ice condensation. Expect to pay $3,000-$6,000 or more.

• Food processor or mandoline – For slicing green beans evenly before freeze drying.

• Mesh drying trays – Trays designed for the freeze dryer to hold the beans in a single layer.

• Cutting board, knife, kitchen shears – For trimming green bean ends.

• Measuring cups, mixing bowls – For blanching and preparing the beans.

• Vacuum sealer or mason jars – For long term storage of the freeze dried beans. Oxygen absorbers also help.

Step-by-Step Instructions

Follow these steps for freeze drying green beans at home:

1. Wash and Prep Beans

Rinse fresh green beans under cool running water. Trim the stem and tip ends with a knife or kitchen shears. Slice the beans into uniform 1⁄4 inch pieces using a mandoline or food processor for even drying.

2. Blanch Beans

Blanching helps stop the enzyme actions that can affect the beans’ flavor, color and texture during freeze drying. To blanch:

• Bring a large pot of water to boiling.
• Add green bean slices and blanch for 3 minutes.
• Drain beans into a colander and immediately dunk in ice water to stop cooking.
• Pat beans dry with paper towels or a clean dish towel.

3. Arrange Beans on Trays

Place the prepped green beans in a single layer on the mesh drying trays designed for your freeze dryer. Make sure none of the pieces are overlapping.

4. Freeze Beans

Put trays of green beans in the freezer for 1-2 hours before freeze drying. This pre-freezing prevents beans from blowing around in the freeze dryer.

5. Load Freeze Dryer

Following your appliance’s instructions, carefully load the trays of frozen green beans into the freeze drying unit. Attach any hoses, close the door securely and turn on the machine.

6. Begin Drying

On most home freeze drying machines, the process will automatically go through all the stages: freezing, pressure reduction, sublimation drying, and desorption.

Drying times vary based on load size and machine specs, but green beans typically take 8-14 hours to fully freeze dry.

7. Check for Dryness

To test for dryness, take a few green bean slices and allow them to return to room temperature in an unsealed container for 10-15 minutes. They should feel dry and brittle when ready.

8. Unload and Pack Beans

Remove the freeze dried green bean trays from the unit. Funnel the lightweight dried beans into airtight storage containers like mason jars or vacuum seal bags. Pack with oxygen absorbers to maintain freshness and prevent oxidation.

9. Label and Store

Label containers with the contents and date. Store in a cool, dry place away from light, heat and moisture. For maximum shelf life up to 25 years, consider storing in the refrigerator or freezer.

And that’s it! With the right equipment and some practice, you can stock up on freeze dried green beans to enjoy their concentrated flavor and excellent nutrient content for years to come.

Frequently Asked Questions

Here are answers to some common questions about freeze drying green beans at home:

How long does it take to freeze dry green beans?

Expect the total freeze drying process to take 8-14 hours depending on your machine and the size of the load. Beans must first be frozen then dried via sublimation under vacuum.

Can you rehydrate freeze dried green beans?

Yes, one benefit of freeze dried beans is how quickly they rehydrate by soaking in water. Place them in a bowl of cool water for 5-10 minutes before cooking or eating. The texture will be similar to fresh beans.

How long do freeze dried green beans last in storage?

Stored in airtight containers in a cool, dry place away from light, freeze dried beans can last 5-10 years. For maximum 25 year shelf life, consider refrigerating or freezing the dried beans.

What is the recommended storage method for freeze dried green beans?

Pack dried beans in mason jars or vacuum sealed mylar bags with oxygen absorbers. Then store in a cool, dark place around 60°F with very low humidity. You can also refrigerate or freeze them.

Can you freeze dry beans without blanching first?

Blanching is highly recommended. It stops the enzyme actions that affect color, texture and flavor during freeze drying. However, some people do skip blanching with mixed results.

Is it safe to eat freeze dried green beans without rehydrating?

Yes, freeze dried beans are safe to eat in the dried state as a crunchy snack due to their low moisture content. However, they have a more pleasant, fresh bean flavor when rehydrated.

What temperature is best for freeze drying green beans?

Most home freeze dryers have a set drying temperature ranging from 95°F to 115°F. Following your unit’s recommended temperature setting produces the best results.

Can you use a food dehydrator instead of a freeze dryer?

No, only a true freeze dryer that vacuum seals and sublimely dries frozen foods retains the same quality. Dehydrators don’t properly freeze dry.

How much does a home freeze drying machine cost?

Expect to pay $3,000 to over $6,000 for a quality small batch freeze drying machine for home use. The investment can pay off if you use it frequently for preserving your garden harvest.

Are there safety risks with home freeze drying?

As with any appliance, follow all manufacturer safety instructions. Only freeze dry foods intended for human consumption. Avoid contamination and food spoilage with proper sanitation, storage and handling.

With the right freeze drying equipment and some practice, you can stock your pantry with nutritious, flavorful freeze dried green beans that will last for many years!