What Is Cold Pack Canning? | The Raw Pack Method Explained

If you’ve come across an old recipe telling you to “cold pack” your green beans or peaches, you might be puzzled about what that actually means. The term has caused plenty of confusion over the years, and even the experts have moved away from it. Cold pack canning simply means you put raw, unprepared food straight into your jars, then run them through the proper canning process. The modern, preferred term for this is raw pack, and it’s a technique worth understanding before you fill your first jar.

The Definition: What Cold Pack Canning Actually Means

Cold pack canning, more precisely called raw pack, means filling jars with fresh, unheated food before processing. The USDA National Agricultural Library (NAL) defines raw packing as the practice of filling jars tightly with freshly prepared, but unheated, food. You’re essentially packing the food into the jar while it’s still in its raw state, then sealing and processing it in a canner.

Penn State Extension notes the term “cold pack” is now often discouraged because it’s used inconsistently. Different sources have applied it to different methods over the years, which has led to real confusion in the canning community. The National Center for Home Food Preservation (NCHFP) agrees, stating that cold pack is often used incorrectly and that raw pack is the preferred term for putting raw food into jars.

Raw Pack vs. Hot Pack: What’s the Difference?

The USDA NAL contrasts raw pack with hot pack. Hot pack means you briefly cook or heat the food before packing it into jars, while raw pack skips that step entirely. Both methods are legitimate, but they’re used for different foods and different situations.

Raw packing is especially suitable for vegetables processed in a pressure canner. Dense vegetables like green beans, carrots, and potatoes hold up well when packed raw because the pressure canning process heats them thoroughly inside the jar. The NCHFP says modern research-based directions usually tell you to pack foods raw or cooked rather than using the ambiguous term “cold pack.”

Here’s where the confusion gets dangerous. Some people use “cold pack” to mean raw packing, while others incorrectly use it for jars processed in boiling water with no regard for the recipe’s actual requirements. Cold pack does not automatically mean safe for any food or any canning method. Safety depends on food acidity, jar pack style, headspace, and whether the recipe calls for a boiling-water canner or a pressure canner.

How to Cold Pack (Raw Pack) the Right Way

Whether you’re new to canning or just want to verify your technique, the steps are straightforward when you follow tested directions.

• Fill jars tightly with freshly prepared, unheated food. Pack the food in firmly, but leave the proper headspace called for in your recipe.
• Use the approved processing method for the specific food. That means a pressure canner for low-acid vegetables and a boiling-water canner for high-acid foods like most fruits and pickles.
• Follow current tested directions rather than generic cold pack instructions from older sources.

One thing to know before you commit to raw packing: it can cause air pockets and discoloration in stored jars, especially with fruit. Trapped air may lead to discoloration within 2 to 3 months of storage. That’s not a safety issue, but it can be a disappointment when you open a jar of peaches that have turned brown. If that matters to you, hot packing is often the better choice for fruit.

Raw packing is more suitable for vegetables processed in a pressure canner, not a blanket method for all foods. Low-acid vegetables need the higher temperatures only a pressure canner can reach, and raw packing works well with that process.

The USDA’s older bulletin, “Home Canning by the One-Period Cold-Pack Method,” describes the method as a USDA-extension practice in the Northern, Central, and Western States. It’s a historical source, not a current authoritative substitute for modern tested recipes. If you come across it in your research, treat it as interesting history rather than practical guidance.

You can find verified, current guidance on packing methods in the National Center for Home Food Preservation’s complete guide to home canning. That document covers both raw and hot packing in detail.

FAQs

Before you stock up on jars, it’s worth checking out our roundup of the best cold pack canning supplies to make sure you have the right equipment for the job.