If you don't see the snowflake symbol, avoid putting your new containers in the freezer. Extreme temperatures can deteriorate plastic, and if containers aren't food safe, this can cause chemicals to spread to food when the containers are taken out of the freezer.
Freeze Safe Symbol: The freeze safe symbol, usually depicting a snowflake or a snowflake inside a triangle, indicates that the plastic container is suitable for freezing food items.
Most food-grade containers can be frozen, but some work better than others. Filmy plastics and paper cartons won't keep moisture out for long. Meat sold on Styrofoam trays and wrapped in clingy plastic will deteriorate quickly and should be rewrapped in freezer or butcher paper or vacuum sealed.
The way to tell which (Ball/Kerr) jars are suitable for freezing is to look at the sides. Straight sides are suitable for the freezer. Any (Ball/Kerr) jar with a ``shoulder'' cannot be put in the freezer safely but is a appropriate for canning.
Only if it says freezer-safe (usually tempered glass). Otherwise, it can crack and that's no fun. Also make sure to remember that liquids expand, and glass has no wiggle room, so if you're freezing in a freezer-safe glass container, you still want to leave a little room at the top.
Freezing Food In Canning Jars, January 21, 2020
Regular mouth jars are not recommended for freezing because of the shoulders. As we know, when liquid freezes it expands. Therefore it is critical that enough headspace is available to allow for this expansion.
Room can be left in containers to account for this expansion but it is not always able to prevent damage to a container. Polypropylene and PVC are both plastics that are brittle at temperatures below freezing. Polystyrene is considered brittle at 68°F and is very brittle at temperatures below freezing.
If a jar is narrow, or has sides that taper inwards, the extra pressure placed on the glass sides as the contents freeze will make it crack (which relieves the stress).
Is your plastic container dotted with a snowflake symbol or two? This means it's safe to stow your container in the freezer—a godsend when you've made a delicious pot of stew and want to keep it around for later consumption.
Glass containers
Glass jars and storage containers are microwavable, dishwasher-safe and often freezable. This puts them among the best ways to freeze food without plastic.
FOR STORING LEFTOVERS IN THE FRIDGE & FREEZER: GLASS
For storing food in the fridge or freezer, glass, particularly OXO's set wins. The containers are freezer-safe so the glass won't break, leakproof with a tight seal (no mysterious liquids sticking to your refrigerator shelves!), and easy to clean.
Being able to freeze food and being pleased with the quality after defrosting are two different things. Some foods simply don't freeze well. Examples are mayonnaise, cream sauce and lettuce. Raw meat and poultry maintain their quality longer than their cooked counterparts because moisture is lost during cooking.
Only put plastics in the freezer if they have a freezer-safe label. Single use containers, such as ice cream or milk cartons, should be avoided for freezer use. According to MSU Extension, use containers in the freezer that are moisture-vapor resistant, leak proof, and easy to seal.
It looks like a recycling symbol (three bent arrows forming a triangle) with a number inside. This symbol does not depict the number of times that the plastic has been recycled, as is commonly believed. Instead, the symbol is used to tell recyclers and waste management handlers what the plastic is made from.
The snowflake or an Igloo indicates the coldest temperature of the freezer from 1–7 it may differ according to the different models of the refrigerator the 7 indicates the highest level so it is indicate by using the snowflake or igloo icons.
Particular types of glass jars and containers are safe to put in the freezer. But not all glass containers are freezer safe. When purchasing glass containers try to choose tempered glass or freezer-safe. This will ensure that your container will remain in one piece when you want to chill your food or drink.
What Are the Best Containers to Use? Glass, plastic and even freezer-safe bags all work perfectly (just make sure the bags are heavy duty). No matter what container you choose, pick something that's airtight.
Our borosilicate glass products can be put into freezer and can resist till -40°c.
The best freezer storage containers to prevent freezer burn are those that provide an airtight seal and lock out moisture. Look for BPA-free plastic containers with snap-on lids or silicone options that stay flexible even in freezing temperatures.
Jars with tapered sides or straight sides are freezer safe; shouldered jars are not.
General Usage: Rubbermaid Glass can be used for storing and heating food. Glassware is freezer, refrigerator, and microwave safe. Use glassware for warming and reheating food in microwave oven and in preheated oven.
It is important to only freeze in mason jars that do not have shoulders (jars that are straight sided or “tapered”) are the easiest because the contents can expand upward in the jar during freezing, especially if you're freezing liquids (jams, jelly, soup, broth, etc).
If using glass containers, be sure they're made of tempered glass that can be frozen. If you're using any type of plastic, be sure it's BPA-free. I especially love freezing soup flat in zip-top gallon-sized bags, as I feel it's a more efficient use of (very precious) freezer real estate.
Most foods will freeze well in glass including fruit, vegetables, soups and sauces, baby food, leftovers, biscuits, and vegetable peels and scraps (great for making stock).