Dark purple elderberries (Sambucus nigra, S. Canadensis) are a fantastic ingredient for baked goods, jelly, pancakes, and homemade wine—you can even make a terrific fruit-flavored vinegar with them. They are also an anti-viral medicinal herb, taken either as a syrup or a tincture.
But, like most berries, they do not last long in the refrigerator or on the counter. If you've got an abundance of elderberries, freezing is a great way to preserve them for future use (or to stockpile them until you have enough for a recipe).
It is also best to freeze elderberries before trying to de-stem them even if you plan to use them right away as it makes the process much easier.
How to Freeze Elderberries
Before placing the berries in the freezer, you need to follow a few steps. First, snip the whole elderberry clusters off of the shrubs, while they are still attached to their main stalks. Then rinse them under water to remove any insects or debris. Spread them on a dishtowel to dry off for a few minutes, and then simply put the whole elderberry clusters into freezer bags or containers. Make sure to pack them in loosely so as not to crush any of the fruit. Seal the bag tightly and freeze.
Freezing to Ease the De-Stemming Process
The flowers and fruits are the only edible parts of the elderberry shrub—the leaves, twigs, roots, and stems are toxic. So before using the berries, you need to remove them from their stems. It is tricky to get the juicy berries off of the stems without squishing them, but once they are frozen you can roll them off of the stems quite easily.
If you will de-stem the elderberries the same day as freezing them, spread them out on a cookie sheet and freeze, uncovered for one to two hours. Once they are frozen solid they are quite easy to remove from the stems by hand. Discard the inedible stems and proceed with the recipe using the berries.
If you are not using the berries right away, transfer the de-stemmed elderberries to freezer bags or containers; seal tightly and return them to the freezer.
Working With a Big Bunch
If you are working with a very large haul of elderberries, you may find that they start to thaw out quicker than you can de-stem them. To avoid this, simply work in smaller batches, only taking a few of the still-on-the-stem elderberry clusters out of the freezer at a time.
When you work with elderberries in a large quantity, it is also helpful to return the just-stemmed, still-frozen elderberries to the freezer quickly. If they have already thawed when you refreeze them, the result will be a big solid brick of fruit. If they are still frozen, the individual elderberries will stay loose in their containers or bags. That makes it easier to take out just what you need when you are ready to use them in a recipe.