Blanching vegetables helps degrade enzymes in vegetables that can cause celery to lose its color, taste and texture. If you find yourself with an abundance of celery that you want to freeze for later use, you should blanch it first to preserve the quality. Make sure to follow directions carefully and blanch the celery for exactly three minutes. Too much or too little time spent blanching both will affect the quality of the vegetables once frozen, the National Center for Home Food Preservation advises.
Wash the celery thoroughly under cool running water.
Trim the ends off the celery pieces using a sharp kitchen knife, the cut the remaining celery into pieces the size you desire.
Fill a blancher with 1 gallon of water for every 1 lb. of celery you will blanch.
Place the covered pot on a stove burner turned on high and wait for the water to boil.
Place the cut-up celery in the blanching basket or insert once the water boils, then affix the lid.
Set a timer for three minutes as soon as you put the celery in the pot.
Remove the blanching insert or basket from the blancher and drain away the excess water.
Place the blanching basket or insert into a pot or another large container filled with ice water and allow the celery to cool completely.
Stir the celery periodically during the cooling process.
Drain the water from the basket or insert once more, making sure you allow as much of the water to drain as possible before freezing the celery.
When cooling celery after blanching it, continually replenish the warming water with cool water, the National Center for Home Food Preservation advises. This will help cool the vegetables more quickly.
If blanched properly, you can store vegetables for up to 18 months in a freezer with a temperature of less than 0 degrees F, the University of Minnesota Extension reports.