6 Best Freezer Jars For Jams And Jellies That Won’t Crack
Avoid cracked glass in your freezer. Our guide reveals the 6 best jars for jams and jellies, designed to withstand freezing temperatures without breaking.
There’s nothing quite like pulling a jar of last summer’s strawberry jam from the deep freeze on a cold January morning. But there’s also nothing more defeating than discovering that jar has a massive crack up the side, leaving your precious harvest unusable. The frustration is real, and it’s a waste of hard work, beautiful fruit, and valuable time.
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Why Your Choice of Freezer Jar Matters for Jam
The science is simple: water expands when it freezes. Since jam and jelly are mostly fruit and sugar dissolved in water, they expand, too. This expansion exerts immense pressure on the walls of its container.
If that container is rigid and has the wrong shape, something has to give. Standard canning jars, with their distinctive "shoulders" below the threads, are the most common victims. The jam freezes from the top down, and as the lower portion expands, it gets trapped by the frozen layer above and the narrow shoulders, forcing the glass to crack under the pressure.
Your choice of jar is about working with this physical reality, not against it. You need a container made of a flexible material that can give a little, or one with straight sides that allows the expanding jam to slide upward without creating pressure points. Getting this right is the difference between a well-stocked freezer and a heartbreaking mess.
Ball Plastic Freezer Jars: The Go-To Standard
When you need something that just works, these are the answer. Ball designed these jars specifically for freezing, and it shows. They are made from a flexible, BPA-free plastic that has just enough give to accommodate the expansion of your jam.
They are practically foolproof. Each jar has a convenient fill line molded into the side, taking the guesswork out of leaving enough headspace. The screw-top lids create a tight seal, preventing freezer burn and messy leaks if a jar gets tipped over before it’s solid.
Of course, the main tradeoff is that they’re plastic. For many of us trying to reduce plastic use in the kitchen, this is a significant downside. But for sheer reliability and peace of mind, especially for a beginner, their purpose-built design is unmatched.
Ziploc Twist ‘n Loc: An Affordable, Reliable Pick
Don’t overlook the simple solutions you can find in any grocery store. Ziploc’s Twist ‘n Loc containers are a surprisingly effective and budget-friendly option for freezer jam. They are widely available, inexpensive, and come in handy 8-ounce and 16-ounce sizes.
Their strength lies in their flexible plastic construction and a lid that provides an excellent seal. You can hear and feel it lock into place, giving you confidence it won’t pop open. The plastic is pliable enough to handle the expansion of freezing jam without any issue.
Are they a forever solution? Probably not. Over time, the plastic can absorb stains and odors from dark berries like blackberries or black currants. They also may not stand up to as many years of repeated use as a dedicated Ball jar. But for their cost and accessibility, they are a fantastic workhorse.
Kerr Wide Mouth Jars: The Best Glass Option
Many people prefer storing food in glass, and it is possible to freeze jam in it if you are careful. The key is to choose the right kind of jar. The only glass jars safe for freezing are those with completely straight sides and a wide mouth.
Kerr’s wide-mouth pint and half-pint jars are a great example. Because they have no shoulders, the expanding jam can move freely upward as it freezes, preventing the pressure buildup that causes cracks. This straight-sided design is non-negotiable for freezing in glass.
Even with the right jar, your technique is critical. You must leave at least a full inch of headspace to give the jam room to grow. Cool the jam completely in the refrigerator before it ever sees the freezer, and consider freezing it with the lid placed on loosely, tightening it only after the jam is solid. It’s more work and carries slightly more risk, but it’s the best way to use glass.
Weck Mold Jars: A Durable, Straight-Sided Choice
If you want a glass option that is both functional and beautiful, Weck jars are a fantastic choice. Their "Mold Jar" line is particularly well-suited for the freezer. These jars are essentially straight-sided cylinders, offering a clear path for expansion.
Made from thick, heavy-duty glass, these jars feel incredibly durable and resist the thermal stress of freezing better than thinner glass. They look great in the freezer and are perfect for gifting. You can see the vibrant color of your raspberry or peach jam right through the crystal-clear glass.
The main consideration is the closure system. The traditional glass lid, rubber ring, and metal clips work, but for the freezer, many people prefer Weck’s separate plastic lids for convenience. The biggest tradeoff is the price—Weck jars are a premium product and a significant investment. But for a beautiful, long-lasting, plastic-free option, they are hard to beat.
Arrow Home Freezer Tubs: Great for Bulk Batches
When you’ve just processed 20 pounds of strawberries, you’re not thinking about pretty jars; you’re thinking about efficient storage. This is where simple, no-frills freezer tubs shine. They are the workhorses for preserving large harvests.
These containers are typically square or rectangular, a major advantage for freezer organization. Round jars waste a lot of space, but these blocky tubs stack neatly and let you pack a chest freezer tight. The thin, pliable plastic is designed to bulge and flex as the contents freeze.
They aren’t fancy. The lids are functional but may not feel as secure as a screw-top, and they certainly aren’t what you’d use for a gift. But for pure utility and maximizing your freezer space after a bumper crop, nothing is more practical.
Rubbermaid Twist & Seal: Secure and Stackable
Rubbermaid’s Twist & Seal containers are another excellent and widely available plastic option that hits a sweet spot between durability and convenience. They feel a bit more substantial than Ziploc containers and offer a truly leak-proof seal.
The "Twist & Seal" name says it all. The lid screws on very securely, which is great for preventing spills when you’re moving liquidy jam into the freezer. They are also designed to be stackable, with indented lids that help keep a stack from sliding around.
Like other plastic options, they can stain over time, and they aren’t meant to last a lifetime. But they are a reliable, mid-range choice that you can trust to keep your jam safe. They represent a great balance of security, stackability, and affordability.
Tips for Preventing Cracking in Any Freezer Jar
The container you choose is only half the battle; your technique is the other half. Following a few simple rules will drastically reduce the risk of cracking, no matter what jar you use. These steps are all about managing expansion and avoiding sudden temperature changes.
Adhering to these practices turns freezing from a gamble into a reliable process. The most important rules are:
- Leave Ample Headspace: Don’t eyeball it. Use a ruler if you have to. A minimum of one inch from the top of the jam to the rim of the jar is a safe bet.
- Cool It Down Completely: Never put warm or hot jam directly into the freezer. Let it cool to room temperature on the counter, then move it to the refrigerator for several hours until it’s thoroughly chilled.
- Freeze Lids Loose (Especially for Glass): For glass jars, place the lid on top without screwing it down until the jam is frozen solid. This gives any trapped air an escape route.
- Thaw Slowly: The risk of cracking isn’t just when freezing, but also when thawing. Avoid thermal shock by moving your jar from the freezer to the refrigerator to thaw overnight. Never run a frozen glass jar under hot water.
Ultimately, these aren’t just tips; they are non-negotiable steps for success. By respecting the physics at play, you can ensure that all your hard work in the garden and kitchen pays off with perfectly preserved jam.
Choosing the right freezer jar is about matching the container to your priorities—whether that’s the foolproof reliability of plastic, the timeless appeal of glass, or the sheer volume needed for a huge harvest. Understanding why jars crack is the first step. By selecting a jar with flexible or straight sides and following proper cooling and filling techniques, you can guarantee that every jar you pull from the freezer is as perfect as the day you made it.
