Raisins, the dried form of grapes, are available throughout the world. Known for their sticky-sweet taste, they are often sold in large batches owing to their small size. The fact that raisins are simply dehydrated grapes make them an excellent candidate for freezing, though they can keep just as well outside of a freezer so long as the conditions are ideal
Yes, raisins can be frozen; Raisins last up to twelve months with very little direct effort at preservation. So long as they are kept away from insects and moisture, they should remain in an edible condition, though the taste and texture will decrease over time1. To avoid this degradation of quality, it is best to freeze your raisins.
Can You Freeze Raisins?
When food, especially food like fresh produce, is placed in a freezer, the water is crystallized both on the surface of the food and at a cellular level within the very cells themselves, in some instances violently damaging the produce in a way that is not immediately visible to the naked eye. Because raisins possess an extremely low moisture content of below fifteen percent, they are not subject to this damaging process, and in fact retain their quality when frozen.2
How Long Do Raisins Last in the Fridge?
Surprisingly, placing raisins the fridge does not alter the shelf life all that much, allowing your raisins to last up to twelve months. If you wish to refrigerate your raisins instead of freezing them, simply place them in an air-tight container.
Refrigerating your raisins for long term storage is ideal so long as they will be consumed within six to twelve months. Refrigerating them is preferable as there will be no need for defrosting should you need to retrieve your raisins.
For longer stretches of time, freezing them is far more recommended to prevent spoilage.
To begin freezing your batch of raisins, the required items are a metal baking sheet that has been patted dry, several resealable plastic pouches depending on how many raisins there are, and a freezer.
Freezing your Raisins
The first step is to individually freeze your raisins so as to reduce large clumps of interconnected fruit. This, asides from being difficult to store, will make it more difficult to thaw the desired amount of raisins needed.
Retrieve your metal baking pan and line it with tissue or similar film-like material. This will ensure that the raisins do not stick to the pan in the event that excess moisture is present on their surfaces. After making sure this will not occur, pour the raisins onto the pan, taking care to avoid large mounds of raisins from forming.
Place the baking pan and the raisins in the freezer. There is no need to cover them as they are already dehydrated, and will not be affected by the low humidity of a freezer. Should you wish to cover the raisins in the event that they may absorb the smell or taste of other produce in your freezer, simply stretch any kind of cling wrap over the baking sheet.
After two hours, remove the baking sheet from the freezer and empty into a resealable container or pouch. This process will ensure that, so long as the raisins remain frozen, they will last for up to one and a half years.
Thawing your Raisins
Should you wish to retrieve your raisins from the freezer, thawing them is quite simple. Simply take the container of fruit and place it in the fridge for several hours, allowing the raisins to gradually return to an edible temperature. Should the need to defrost them be more immediate, instead place the container on your counter-top and allow the room’s temperature to thaw them.
Can You Freeze All Types of Raisins?
While there are only two commonly found types of raisins, namely from both red and white grapes, they all share the same properties of low moisture content and high sugar content, meaning that most if not all types of raisins hold up well to the freezing process. So long as procedures are followed appropriately, they should all keep well for over a year.
Raisins Signs of Spoilage
In the unlikely event that your raisins have spoiled in the freezer, or perhaps even before storing them, there are a few clear warning signs.
Raisins, being dried fruit with generally darker skin, are somewhat harder to inspect than fresh produce. If the quality of your raisins are in question, do not attempt to taste them and instead simply smell them for any odor of fermentation or sourness. Visually, off-color patches and unusual growths may be signs of mold or other forms of fungal colonization. This is entirely uncommon as most forms of fungal growth require moisture.
To avoid the introduction of moisture, ensure that the raisins are dry before storing, and that your container is absolutely air-tight so as to prevent humid air from condensing within.
Raisins may occasionally harden in the event that they have been exposed to evaporating conditions for too long. This is entirely normal, and is not a sign of spoilage, though the texture may be unpleasant. Hardened raisins may still be used in dishes that may mask the texture, such as in sauces and baking.
If you are using multiple batches of raisins from different sources, it is important to inspect them before freezing, as even a handful of spoiled raisins can release both enzymes and bacterial cultures, eventually spoiling the entire batch.
While the generally accepted length of time that raisins are safe to eat while frozen is eighteen months, in ideal conditions, raisins can last indefinitely. This is as of yet subject to academic study, and requires temperatures around or below zero as well as perfect packaging.
1. Unknown Author (July 2016) United States Standards for Grades of Processed Raisins, US Department of Agriculture
2. J.P. Zoffoli, B.A. Latorre (2011). 9 – Table grape (Vitis vinifera L.) Woodhead Publishing series, University of Washington D.C