Vacuum sealing soup works, but you need to freeze it solid first or use a special technique to keep liquid from being sucked into the machine
Vacuum sealing soup is possible, but it's different from sealing dry foods. The problem is that a standard vacuum sealer pulls air out of the bag by creating suction, and that same suction will pull liquid up into the machine's vacuum chamber and potentially damage it. The solution is to freeze your soup completely before sealing, or to use a water displacement method that doesn't rely on the machine's suction.
Most home cooks find freezing the easier route. Pour your cooled soup into a freezer bag, freeze it flat or in a block until it's solid, then run it through the vacuum sealer. The frozen soup won't be drawn into the machine, and you'll get an airtight seal that keeps freezer burn away for months longer than an unsealed bag would.
Key Takeaways
- Freeze soup completely before vacuum sealing it, or the liquid will be pulled into your machine and may cause damage.
- Pour cooled soup into a freezer bag, lay it flat to freeze, then seal it once it's solid throughout.
- The water displacement method (sealing the bag while submerging it in water) works without a machine but takes more time and care.
- Vacuum-sealed frozen soup keeps for three to four months in the freezer, compared to two to three months in an unsealed bag.
- Thaw vacuum-sealed soup in the refrigerator overnight, or reheat it directly from frozen on the stovetop over low heat.
Freezing soup flat before sealing
The flat-freeze method is the most practical for home use. Let your soup cool to room temperature, then pour it into a quart-sized or gallon-sized freezer bag. Lay the bag flat on a sheet pan or cutting board and place it in the freezer. Leave it there for at least eight hours, or until the soup is completely frozen solid.
Once frozen, remove the bag from the freezer and run it through your vacuum sealer according to the machine's instructions. Because the soup is solid, the sealing process will work normally—the machine will pull air from the bag without drawing liquid into the chamber. You can then store the sealed bag upright or flat in your freezer.
This method works with any soup: broth, cream-based soups, vegetable soups, and chunky stews. The texture of the soup doesn't change during freezing or reheating, though very delicate ingredients like fresh herbs or soft vegetables may lose some firmness.
The water displacement method for sealing without freezing
If you want to seal soup without freezing it first, you can use the water displacement method. Fill a large pot or bowl with water and bring it to room temperature—it should not be hot. Pour your cooled soup into a freezer bag, leaving about an inch of space at the top.
Slowly lower the bag into the water, keeping the opening above the waterline. The water pressure will push air out of the bag as it sinks. Once the bag is submerged up to the seal line, quickly close the bag or use a handheld sealer to seal just the top inch. Remove the bag from the water and let it drain.
This method creates an airtight seal without using your vacuum machine, so there's no risk of liquid damage. However, it's slower and requires more attention than freezing. The soup will still need to be refrigerated or frozen after sealing, and it won't keep as long as vacuum-sealed soup does.
How long vacuum-sealed soup lasts in the freezer
Vacuum-sealed soup keeps for three to four months in the freezer at 0°F or below. This is significantly longer than soup in an unsealed freezer bag, which typically lasts two to three months before freezer burn becomes noticeable. The airtight seal prevents ice crystals from forming on the surface and protects the soup from absorbing odors from other foods.
Refrigerated vacuum-sealed soup (not frozen) lasts three to four days, the same as soup stored in any airtight container. If you're sealing soup to keep it in the fridge rather than the freezer, the vacuum seal's main benefit is preventing spills and keeping odors contained.
Thawing and reheating vacuum-sealed soup
To thaw frozen vacuum-sealed soup, move the bag to the refrigerator and leave it overnight. This is the safest method and prevents bacterial growth. Once thawed, pour the soup into a pot and reheat it over medium heat, stirring occasionally, until it reaches a simmer.
You can also reheat soup directly from frozen without thawing first. Place the sealed bag in a pot of hot water (not boiling) for 15 to 20 minutes, or until the soup is warm enough to pour. Alternatively, cut open the bag and pour the frozen soup directly into a pot, then heat it over low heat, stirring frequently to break up the block and heat it evenly.
Do not microwave soup while it's still in the vacuum-sealed bag, even if the bag is labeled microwave-safe. The seal may burst from steam pressure, or the bag may release chemicals when heated. Always transfer the soup to a microwave-safe container first.
Preventing common mistakes when sealing soup
The most common mistake is trying to seal liquid soup without freezing it first. This damages the vacuum sealer and wastes the soup. Always freeze first, or use the water displacement method instead.
Another mistake is overfilling the bag. Soup expands slightly as it freezes, so leave at least an inch of headspace at the top of the bag. If the bag is too full, the soup may push out of the seal line during freezing, and you'll lose the airtight seal.
Don't seal soup that's still warm or even room temperature. Warm liquid will create steam, which can warp the bag or prevent a proper seal. Always let soup cool completely before freezing or sealing.
Choosing the right bag for soup
Use freezer bags rated for vacuum sealing, not regular storage bags. Freezer bags are thicker and designed to withstand the pressure of the vacuum process. Quart-sized bags work well for individual portions, while gallon-sized bags are better for larger batches.
Some vacuum sealer machines come with special bags designed for that specific model. Check your machine's manual to see whether you need to use those bags or whether standard freezer bags will work. Freezer bags from any brand will generally work with any vacuum sealer, but the machine's own bags may seal more reliably.
Avoid using thin plastic bags or bags not labeled for freezer use. These won't protect the soup as well and may tear during the sealing process or in the freezer.
Frequently Asked Questions
Can I vacuum seal hot soup?
No. Hot soup will create steam that can warp the bag and prevent a proper seal. Always let soup cool to room temperature before sealing, and freeze it solid before running it through the vacuum sealer.
What happens if liquid gets into my vacuum sealer?
Liquid in the vacuum chamber can damage the machine's motor and sealing strip. If this happens, unplug the machine when ready and let it dry completely before using it again. If liquid has been inside for more than a few hours, the machine may need professional cleaning or repair.
Can I vacuum seal cream-based soups?
Yes, as long as you freeze them first. Cream-based soups freeze and thaw well and don't separate or change texture noticeably. Follow the same freezing and sealing process as you would for any other soup.
Do I need a special vacuum sealer for soup?
No. Any standard vacuum sealer will work with frozen soup. You don't need a chamber sealer or any special equipment—just freeze the soup solid before sealing it with your regular machine.
Can I refreeze vacuum-sealed soup after thawing it?
Yes, as long as you thawed it in the refrigerator and it hasn't been at room temperature for more than two hours. Refreezing doesn't affect the quality of soup significantly, though the texture may become slightly softer with each freeze-thaw cycle.