Summer is the best time to take care of your supply of berries for the cold season. Freezing does not require complicated preparations, but it does have its own rules. UNN explains in more detail how to prepare, properly freeze, package, and thaw berries so that they retain their flavor and properties as well as possible.
Which berries are worth freezing
Ripe but not overripe, undamaged berries are best suited for freezing. Before preparing them, you need to sort them and remove spoiled fruit, leaves, stems, and other debris. If using strawberries, remove the stems. Cherries can be pitted before freezing. Large berries can be cut into pieces if necessary.
It is important not to put off freezing for too long. The fresher the berries are when prepared, the better suited they will be for storage.
How to prepare berries for freezing
Before freezing, the berries should be washed and allowed to dry completely, as excess water on the surface will turn into ice, which can cause the fruit to stick together. After washing, the berries should be spread in a thin layer on a towel or another clean surface. Only after they have dried can you proceed to freezing. This is especially important for berries you plan to freeze whole. One of the simplest methods is to first freeze the berries separately and only then place them in bags or containers. To do this, arrange the prepared berries in a single layer on a baking sheet or tray lined with parchment paper. It is important that the fruit not be piled closely together. Place them in the freezer until completely firm. Then transfer the frozen fruit to special bags or airtight containers. This method helps prevent the formation of one large frozen clump.
Freezing times may vary for different berries. For example, blueberries usually freeze in approximately 1–2 hours, while other berries may require more time.
How to package berries properly
After the initial freezing, the berries should be divided into small portions. This is convenient if only a small amount of the product is needed for cooking in winter.
Airtight containers or strong moisture-resistant bags designed for freezer use are suitable for storage. As much excess air as possible should be removed from the packaging, and each bag or container should be labeled with the type of berries, the freezing date, and, if necessary, the quantity of the product. The freezer should not be overloaded when adding fresh berries. Quick freezing helps reduce damage to the fruit’s structure. The optimal temperature for freezing fruits, berries, and vegetables is −18 °C or lower.
Can berries be frozen with sugar?
Yes, some berries can be prepared with sugar. For example, after washing and drying, strawberries can be sprinkled with sugar. To do this, place the berries in a container in layers, sprinkling sugar over each layer. Approximately 1/4–1/2 cup of sugar is used for 1–2 cups of strawberries, but the amount can be adjusted depending on the sweetness of the berries and personal taste.
After that, leave the strawberries for approximately 15 minutes so that they release juice and the sugar dissolves. Then close the container and place it in the freezer. It is advisable to leave a little free space, as the berries may release juice during freezing.
Berry purée as a freezing method
Berries can be frozen not only whole. They can also be blended or ground using a meat grinder, after which they are transferred to containers or special bags.
Sugar or honey can be added to the berry purée to taste, and this preparation is well suited for later use in smoothies, desserts, sauces, and other dishes. For blueberry purée, the material recommends using 1 cup of sugar for every 2 liters of crushed berries. The sugar is melted over medium heat, then mixed with the blueberries, cooled, and portioned for freezing.
How long can frozen berries be stored?
The storage period depends on the type and preparation method. Usually, berries can be stored in the freezer for about six months. For blueberries and blueberry purée, a storage period of up to 10 months is recommended, although it is best to use them within the first six months.
Frozen products can also be stored for longer, but their quality may deteriorate over time.
Why berries become soft after thawing
Not all berries retain their original shape after being removed from the freezer. The reason is related to the water contained inside the fruit. During freezing, it turns into ice crystals that damage the cell walls, which is why berries may become softer and lose some of their juice after thawing.
Rapid freezing helps reduce these changes. The faster the fruit freezes and the lower the temperature, the fewer ice crystals form and the less the berries' structure is damaged.
How to thaw berries properly
Thawing is no less important a step than the preparation itself. Berries should be thawed slowly and in the refrigerator.
At the same time, delicate berries are best used before they have fully thawed, as they may lose their shape afterward. If their texture has nevertheless changed, such berries can be used in yogurt or smoothies.