Preserving food using cold-fill hold 

Cold-fill hold is a preservation method used to ensure that food products are both safe and shelf-stable. It requires an initial heat treatment and, after bottling, can be stored at room temperature.

Cold-fill hold is especially valuable for those who wish to process foods that may lose quality if exposed to high heat before bottling, such as mustard or certain sauces. This method is also ideal for products packaged in materials that cannot withstand high temperatures.

Because cold-fill hold does not include a high-heat filling step, it is critical to follow proper food safety protocols to ensure the safety of consumers.

Container selection and sanitation

Before processing, ensure jars and lids are clean and food-grade. The lid must have a continuous thread closure; two-piece flat and ring lids used for water bath canning will leak.

To sanitize containers and lids, apply a food-grade sanitizer following the manufacturer's instructions. For example, you may use unscented liquid chlorine bleach (sodium hypochlorite). To use chlorine bleach safely and effectively, it must be diluted the day it’s used.

To 1 gallon of water, add:

• 1 tablespoon bleach at 2.75 percent strength, or
• 2 teaspoons bleach at 6.25 percent strength, or
• 1 teaspoon bleach at 8.25 percent strength

Heating and cooling step

An initial heating step is critical and must be sufficient at inactivating vegetative microorganisms, which, when active, may cause foodborne illness.

Time and temperature are important factors. For example:

• Heat a mixture to 165 degrees Fahrenheit for 10 to 15 minutes, ensuring all parts of the food are heated to at least 165 degrees Fahrenheit for a minimum of 1 minute 12 seconds.
• After the heating step, cool the food to 50 to 70 degrees Fahrenheit before bottling.
• Placing the mixture in the refrigerator will increase the cooling rate.

pH

Cold-fill hold requires a lower pH than traditional water-bath or hot-fill hold methods. The final product must have a pH of 3.3 or lower. However, a pH of 3.5 or lower is acceptable if the food is formulated with 2.5% acetic acid.

In cases where the food contains both 2.5% acetic acid and 0.1% benzoic acid, a final pH of 3.8 is acceptable. Both acetic acid and benzoic acid act as preservatives, inhibiting the growth of harmful microorganisms.

Test the pH of your final product after it has been processed and cooled using a pH meter designed for liquids.

Filling container

After the heating step, the food must be cooled before being poured into sanitized, food-grade containers. Once the container is filled, securely fasten the continuous thread lid and invert the container. The low pH of the food acts as a sanitizing agent during this process. 

Example process

1. Heat mixture to 165 degrees Fahrenheit for 5 minutes.
2. Cool the mixture to room temperature.
3. Fill the mixture into sanitized containers and ensure the mixture is at least 50 degrees Fahrenheit, with a half inch of headspace.
4. Put the lid on securely and invert the bottle.
5. Turn containers upright and hold for at least 6 days at 50 degrees Fahrenheit or above.
6. Record holding time and temperature in a physical or digital log.