All nuts contain natural oils that will become rancid over time when stored at room temperature. Freeze shelled almonds and walnuts to keep them fresh during storage, which can be up to one to two years, according to the University of California, Davis. Take out and thaw only as many as you need for snacks or recipes. Buy nuts in bulk and shell them during the harvest season to freeze and enjoy year round, or take advantage of holiday sales. Freezing almonds and walnuts requires no special equipment or processing, but freshly shelled nuts should be dried in a single layer for 24 hours prior to freezing.
Write the nut type and the date on each zip-top bag with a permanent marker.
Put shelled nuts into zip-top freezer bags. Fill the bags as full as desired, leaving enough space to zip the top closed.
Hold the top of the bag with one hand and pinch at the edge over the zipper with the other hand to lock the two sides together. Slide your finger and thumb across the width of the bag to 1 inch from the end to press the zipper closed.
Place a drinking straw 2 inches into the bag through the opening. Put your mouth over the end of the straw and inhale to suck the air out of the bag. Pull the straw from the bag with your teeth while inhaling, and simultaneously pinch the rest of the zipper closed.
Place the bags of nuts in the freezer. Take out the quantity desired and thaw to eat as a snack or add to a recipe.
There is no need to repackage unopened commercially packaged nuts prior to freezing. You can substitute plastic freezer containers for zip-top freezer bags. Use bags or containers especially designed for freezing foods to prevent freezer burn and ensure maximum freshness.