How do you freeze blueberries so that there are ice crystals inside?
I eat frozen blueberries straight out of the freezer multiple times a day, and sometimes I buy a bag and the blueberries inside are frozen perfectly so that the core of the blueberry has crunchy ice crystals, and the outside doesn't, resulting in a massive burst of blueberry flavor. Can someone tell me how to freeze blueberries this way myself? I'm pretty sure this isn't a common question so please don't be afraid to post an answer that you aren't sure is correct, because this is top of the line blueberry science that is very experimental, and i'm willing to try multiple freezing techniques to get the perfect result.
Best Answer
Normally freezing processes try to avoid forming large ice crystals by freezing rapidly and maintaining a temperature well below the freezing point of the liquid in the product (not simply 0°C due to sugar and other solutes, which concentrate as some liquid freezes).
I suspect that the ones you are aiming to imitate have been through a thermal cycle in transit -- quite possibly as you take them home.
So you can try to do the opposite. Freeze fresh blueberries at home, in a single layer but fairly slowly (perhaps freezing them in an isulated container and/or adding large containers of room temperature water to the freezer at the same time). Allow to nearly defrost and freeze again. If you're starting from frozen berries, allow them to nearly defrost and then refreeze slowly.
You'll have to be careful about the quality of other things in your freezer doing this, and the goal is to stay cold enough that food safety isn't an issue, or at least no more of an issue than keeping fresh berries in the fridge for a few days before freezing. As a result I leave the mechanics at an exercise for you. A cool box with a thermometer inside may be useful.
Pictures about "How do you freeze blueberries so that there are ice crystals inside?"
Quick Answer about "How do you freeze blueberries so that there are ice crystals inside?"
Place the blueberries in a single layer on a parchment paper-lined baking sheet and freeze for at least 1-2 hours or up to overnight. Once firm, transfer the berries to a freezer-safe bag, breaking apart any berries that are stuck together.How do you properly freeze blueberries?
To freeze blueberries, spread the blueberries on a rimmed baking sheet in a single layer. Place in the freezer for two hours, then pack the blueberries for long-term storage.Does freezing blueberries change the texture?
When fruits like blueberries experience freezer burn, it adversely affects their taste and texture. You won't get that full flavor and juicy texture from them if they were damaged in the freezer.Do you need to wash blueberries before freezing them?
Don't wash the blueberries before freezing them. Yes, it sounds counterintuitive, but there's a good reason for this. Blueberries have a natural waxy coating on their skins called the bloom. The bloom protects the blueberries from pests or bacteria, and it also helps them stay nice and juicy.How do you flash freeze blueberries?
Line the cookie sheet or pan with plastic wrap (or other lining), then add one layer of blueberries. Try to see that they're not touching; you want to flash-freeze them individually. Put the pan on a level freezer shelf and freeze for 30 minutes. Remove the pan and immediately scoot the berries into your plastic bag.How to Freeze Blueberries
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Skylar Kang, Vivien Pintácsi, Charlotte May, Marisol Peinado