Freezing food is a fantastic way to preserve leftovers, prepare meals in advance, and reduce food waste. If you’re considering using canning jars for freezing, you likely have questions about their suitability and safety. This guide will delve into everything you need to know about freezing food in canning jars, from the types of jars to use to the best thawing practices.
What Type of Jars Can I Freeze In?
The type of jar you use is crucial for successful freezing. The most important factor is the shape.
Straight-sided or tapered jars are the best choice for freezing. These jars allow the contents to expand upwards as they freeze, which is especially important for liquids like soups, broths, jams, and jellies.
Freezer Safe jar chart
Alt text: Ball canning jars labeled as freezer safe, highlighting straight-sided designs that accommodate expansion.
Avoid using jars with shoulders or necks, such as sauce and woozy bottles. As the contents expand, the narrow opening can cause the glass to break. If you’re unsure whether a jar is suitable for freezing, consult the manufacturer or supplier. The image above illustrates which Ball jars are freezer-safe.
While straight-sided jars are generally recommended, you can freeze smaller portions of solid foods like grilled chicken, beef BBQ, or meatballs in other food-grade jars. However, always ensure there’s enough room for expansion.
Which Lids Should I Use for Freezing?
The lid you choose is just as important as the jar itself. To maintain an airtight seal, use lids with a plastisol or foam liner.
Reusing spent flat canning lids or single-piece lids is an excellent way to save money and reduce waste. These lids provide a reliable seal to keep flavors in and air out. Single-piece lids are particularly convenient for jams and other products you’ll access frequently. Plastic lids with foam liners are another viable option.
Ball also offers leak-proof storage lids specifically designed for wide-mouth and regular-mouth canning jars. These lids are not for canning or preserving but are ideal for freezer storage.
How Much Can I Put in a Jar for Freezing?
Proper headspace is essential to prevent breakage during freezing. Many Ball jars have a “FOR FREEZING—FILL HERE” line embossed on the glass. This line indicates the maximum fill level for freezing.
A general rule of thumb for any jar is to fill it to a little below the collar or to the freeze line if one is present. Leaving adequate headspace allows the contents to expand without putting excessive pressure on the glass.
What’s the Best Way to Fill a Jar for Freezing?
Glass is susceptible to thermal shock, so avoid abrupt temperature changes. Most food-grade glass can withstand a 90-degree Fahrenheit (32-degree Celsius) temperature difference. Therefore, maintain consistent temperatures when filling and thawing jars.
Start with clean, room-temperature jars (around 70°F or 21°C). Fill the jars with food that has cooled to around 160°F (71°C) and allow them to cool to room temperature before placing them in the freezer. This gradual cooling process minimizes the risk of thermal shock.
What’s the Best Way to Thaw a Jar and its Contents?
Proper thawing is crucial to prevent breakage and maintain food safety.
To safely defrost jars, place them on a dish towel or paper towel on a plate or tray to catch condensation. Allow the jars to thaw in the refrigerator overnight or on your counter if you can monitor them closely.
If you need to speed up the process, you can place the jars in a few inches of lukewarm water. However, never microwave a frozen jar, as the rapid temperature change can cause it to shatter.
More Freezing Tips
- Always label your jars with the contents and date to keep track of what’s inside.
- Consider freezing in smaller portions to avoid thawing more than you need.
- Ensure the food is properly cooled before freezing to prevent ice crystal formation.
- Use a freezer inventory to help you keep track of what you have frozen and when it needs to be used.
Freezing food in canning jars can be a safe and effective way to preserve your favorite dishes. By following these guidelines, you can confidently utilize canning jars in your freezer and enjoy the benefits of home-preserved foods.
