Plastic Containers for Freezing Soup | What’s Safe & What to Skip

It’s late on a Sunday, you’ve got a pot of turkey soup that tastes even better than you hoped, and you want to stash half of it in the freezer for a busy weeknight. The question hits fast: are the plastic containers in your cabinet going to leach chemicals into that meal you worked for? The answer depends on three numbers you’ll find on the bottom of every container. Here’s exactly how to read them, which materials to trust, and — just as important — which to leave on the shelf.

Which Plastic Resin IDs Are Safe for Frozen Soup?

The recycling triangle on the bottom of a container tells you everything. For freezing soup, you’re looking for IDs 2, 4, or 5, and only when the container also says “BPA-free,” “phthalate-free,” and “freezer-safe.”

ID 4 (LDPE) is safe in solid containers like freezer bags, but the same resin used as thin cling wrap is a known source of phthalates — so stick to the thicker bag or solid container form.

Plastics to Never Use for Frozen Food

The three IDs you’ll see most often that fail the safety test are 1 (PETE), 3 (PVC), 6 (PS), and 7 (Polycarbonate). Single-use water bottles (ID 1), Styrofoam (ID 6), and polycarbonate (ID 7, which can contain BPA) are not built to handle freezer temperatures without degrading.

Why Experts Recommend Glass or Stainless Steel Over Plastic

Plastics can leach metals and chemicals, and that leaching increases significantly when containers are heated, scratched, or used for older food.

The safest route for the long haul is glass (Pyrex, Mason jars), stainless steel, or ceramic. These materials are non-reactive, heat-tolerant, and don’t break down with repeated freeze-thaw cycles. Food-grade silicone is another option that handles freezer, microwave, and oven temperatures without hardening or cracking.

If you’re looking for the best options across all materials — plastic, glass, and stainless — our hands-on guide to the top containers for freezing soup covers the models that actually hold up to repeated use and freezer burn.

How to Freeze Soup Safely — the Right Steps

Follow this order every time.

1. Cool the soup first. Refrigerate it overnight before freezing. Never put hot soup directly into any container — the temperature shock can crack glass and degrade plastic seals.
2. Choose your container. Wide-mouth jars with straight sides (no “shoulders”) prevent breakage from expansion.
3. Leave headspace. Soup expands as it freezes, and ignoring this rule is the most common cause of broken jars and popped lids.
4. Seal it tight. Use airtight lids. For bags, squeeze out as much air as possible before sealing — excess air causes freezer burn and spoilage.
5. Organize for cold. Place containers near the freezer vent (the coldest spot) and reserve the door for sturdy items you’ll use soon. Use sheet pans to create flat, stackable layers in pull-out drawers.
6. Thaw in the fridge. Move frozen soup to the refrigerator overnight. If you need it faster, submerge sealed bags in cold water (change the water every 30 minutes) or use the microwave’s defrost setting and cook immediately. Never transfer frozen food directly from the freezer to a slow cooker — it spends too long in the bacterial danger zone.

The models below meet the safety standards and earned top marks from the latest roundup reviews. All three are BPA-free, phthalate-free, and rated for freezer temperatures.

What Size Container Works for Batch Cooking?

Large batches of soup — the kind you make on Sunday to eat through the month — need containers that hold 4–8 cups. That’s one standard stockpot’s worth divided into two or three containers. Small batches or single portions work best with 1–4 cup containers, which fit easily into lunch bags and microwave safely.

Stackable designs with flat sides or dedicated vent holes for filling save serious freezer space. Souper Cubes are the standout for portion control: each 1/2-cup cube freezes individually, so you pop out exactly what you need for lunch without thawing the whole block.

Quick Facts: Safe vs. Unsafe Plastic Containers

Common Mistakes That Ruin Frozen Soup

The biggest failures come from five habits that are easy to change:

• Reusing non-food HDPE containers.
• Using LDPE cling wrap as a lid. Use a proper lid or beeswax wrap instead.
• Overfilling glass jars. Liquid expands when frozen. Ignoring the 2-inch headspace rule is why jars crack in the freezer.
• Microwaving plastic. Pour soup into a glass bowl before reheating.
• Keeping scratched or old containers. Scratches harbor bacteria and create more surface area for leaching.

6-Step Freezer Safety Checklist

Run through this list before you close the freezer door on a batch of soup. It catches the three most common trip-ups — overfilling, hot food, and wrong container — in about ten seconds.

1. Resin ID is 2, 4, or 5 — and the container says freezer-safe
2. Label says BPA-free and phthalate-free (or go with glass to skip the check)
3. Soup is fully chilled in the fridge (below 40°F / 4°C)
4. Headspace is at least 2 inches below the rim
5. Lid is airtight and the seal is dry and clean
6. Container is placed near the freezer vent (0°F / -18°C), not in the door