SuNutri
SuNutri
All Preservation Methods
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Freezing

The easiest preservation method for most fruits and vegetables, retaining nutrients and fresh flavor.

15-20 min read
Shelf Life: 8-12 months for best quality; safe indefinitely if kept frozen

Overview

Freezing is the simplest and most forgiving preservation method. It retains more nutrients and fresh flavor than any other method, and works for nearly all fruits and vegetables. The key to success is proper preparation (blanching for most vegetables), quick freezing, and airtight packaging.

Best For:

Most vegetables (with blanching)All berries and most fruitsTomatoes (for cooking)Peppers (no blanching needed)Herbs (freeze in oil or water)CornPeasGreen beans

Not Recommended For:

Lettuce and salad greensCucumbers (become mushy)Raw potatoes (turn gray)Whole eggs in shellMayonnaise-based foods

Safety First

Freezing is very safe but doesn't kill bacteria - it only stops their growth. Thaw safely and use proper food handling.

Important Warnings:

  • Keep freezer at 0°F (-18°C) or below
  • Thaw in refrigerator, cold water, or microwave - never at room temperature
  • Once thawed, use within 1-2 days
  • Don't refreeze thawed raw foods unless cooked first
  • Leave headspace in containers for expansion

Equipment Needed

Essential Equipment
  • Freezer

    Chest or upright freezer at 0°F (-18°C) or below

  • Freezer Bags

    Heavy-duty bags designed for freezing

  • Large Pot

    For blanching vegetables

  • Ice Bath

    Large bowl with ice water for stopping cooking

  • Baking Sheets

    For flash freezing before bagging

  • Permanent Marker

    For labeling bags and containers

Optional Equipment
  • Vacuum Sealer

    Removes air for longer storage

  • Freezer Containers

    Rigid containers for soups, sauces

  • Blanching Basket

    Makes blanching easier

  • Food Processor

    For pureeing before freezing

Step-by-Step Guide

1Select and Prepare Produce

Choose ripe, high-quality produce and wash thoroughly.

  • Use produce at peak ripeness
  • Wash under cool running water
  • Remove stems, pits, or seeds as needed
  • Cut into uniform pieces
2Blanch Vegetables (if required)

Brief boiling followed by ice bath stops enzyme action.

  • Bring large pot of water to rolling boil
  • Add vegetables (1 lb per gallon water)
  • Start timing when water returns to boil
  • Transfer immediately to ice bath
  • Cool for same time as blanching
  • Drain thoroughly
Tip: Most vegetables need blanching; most fruits do not
3Treat Fruits (optional)

Prevent browning with ascorbic acid or sugar pack.

  • Light-colored fruits (apples, peaches) benefit from treatment
  • Ascorbic acid: 1/2 tsp per quart water
  • Sugar pack: mix fruit with sugar (3/4 cup per quart fruit)
  • Syrup pack: cover with cold sugar syrup
  • Dry pack: freeze without treatment (works for berries)
4Flash Freeze (recommended)

Spread on baking sheet and freeze before bagging.

  • Line baking sheet with parchment
  • Spread produce in single layer
  • Freeze until solid (1-2 hours)
  • Transfer to bags or containers
Tip: Flash freezing prevents pieces from clumping together
5Package for Freezer

Remove air and seal tightly in freezer-safe containers.

  • Leave 1/2 inch headspace for dry pack
  • Leave 1 inch headspace for liquid pack
  • Remove as much air as possible
  • Seal securely
  • For vacuum sealer: follow manufacturer directions
6Label and Freeze

Mark contents and date, freeze quickly.

  • Write contents, date, and quantity
  • Place in coldest part of freezer
  • Don't overload freezer - air needs to circulate
  • Allow 24 hours to freeze solid

Processing Times

FoodPrep MethodContainerTime
Green BeansBlanch 3 minN/ABlanch 3 min
BroccoliBlanch 3 minN/ABlanch 3 min
Corn (cut)Blanch 4 minN/ABlanch 4 min
PeasBlanch 1.5-2 minN/ABlanch 1.5-2 min
SpinachBlanch 2 minN/ABlanch 2 min
PeppersNo blanching neededN/ANo blanching
TomatoesNo blanching neededN/ANo blanching
BerriesNo treatment neededN/AFlash freeze
PeachesAscorbic acid treatmentN/ATreat then freeze
ZucchiniBlanch 3 minN/ABlanch 3 min

Storage Guidelines

Storage Conditions
Location:

Freezer at 0°F (-18°C) or below

Conditions:

Consistent temperature, away from door

Shelf Life:

8-12 months for best quality; safe indefinitely if kept frozen

Signs of Spoilage
  • Excessive ice crystals (freezer burn)
  • Off-odors when thawed
  • Discoloration
  • Mushy or watery texture (quality, not safety)

Labeling Best Practices

Required Information:

  • Contents
  • Date frozen

Recommended:

  • Quantity
  • Blanching time used
  • "Use by" date
Example Label: Green Beans - Blanched 3 min - Sept 2024 - Use by May 2025

Troubleshooting

Other Preservation Methods