Ketchup is a staple condiments found in every American household and is naturally paired with fried food, burgers, hotdogs, and the like. Companies such as Heinz Co. have popularized the condiment all over the world.

However, not everyone may be consuming ketchup regularly or are buying in bulk, resulting in a few problems with storage and extending its shelf life. Instead of throwing away a bottle of ketchup that may be near or past its expiry date, its shelf life can be extended by freezing. 

Ketchup’s Shelf Life 

When left unopened, ketchup can keep fresh for up to two years. Once opened, it stays fresh for about a year and is best stored in the refrigerator. Freezing ketchup extends its shelf life for up to several years with very few changes to its flavor after defrosting. 

The shelf life of ketchup is typically one to two years because of food preservatives like benzoic acid and sorbic acid. These are the same preservatives used in other common food items such as bread, soda, and ultra-high-temperature (UHT) milk. 

Preservatives are necessary since tomatoes are seasonal and expire quickly on their own. Moreover, the high water content of tomatoes encourages the growth of microorganisms in the condiment which can result in mold and spoilage. Elements of the processing method and pressured packaging all help extend the shelf life of commercial ketchup. 

What is Ketchup? 

Ketchup’s main ingredients are tomatoes, sugar, vinegar, spices, and preservatives. Sweeteners range from cane sugar to beet sugar, glucose syrup, and/or corn syrup. White distilled vinegar adds to the acidity of the tomatoes and also acts as a natural preservative. The thicker the consistency of the ketchup the higher ratio of sugar and spices are added relative to the tomatoes. 

Packaging 

Heinz Co. has dominated the mass production of ketchup with its narrow-neck bottles. The bottle was designed so that ketchup could be easily poured while minimizing its exposure to air. Exposure to air results in making the sauce darker and thicker in time. 

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Ketchup should not be frozen in a glass bottle due to the expansion of water

A clear glass container was ideal as it allowed consumers to view the product and did not cause chemical reactions to the ketchup. Eventually, plastic food-grade squeeze bottles became more convenient. Today, environmental concerns over plastic pollution resulted in the development of recyclable plastic containers. 

Freezing Ketchup 

Since the condiment has a high percentage of water, it freezes rapidly like ice. When you defrost it, ketchup tends to separate because of the weight difference between water and the rest of the ingredients. The defrosted ketchup needs to be stirred together for all the ingredients to be combined into their original form. 

While ketchup freezes well, there are certain do’s and don’ts when it comes to freezing the condiment. For starters, ketchup is prone to freezer burn so it should be stored in a sealed container before keeping in the freezer.

Second, ketchup in glass bottles should never be put directly in the freezer because the bottle could explode. This is because water expands when it freezes and since ketchup has high water content, it expands as well. 

The condiment can also be frozen in smaller portions or batches using an ice tray or silicone mold. Simply pour the ketchup into the mold and gently tap to even out the contents and freeze until it’s solid. After the ketchup is solid, the portions can be placed in a re-sealable bag or any other reusable container. A properly sealed container will prevent exposure to moisture, which leads to freezer burn. 

The same freezing tips apply to those who make their own ketchup or fresh tomato sauce. There are several advantages for making your own tomato sauce or ketchup such as controlling the amount of sugar in the recipe, the absence of preservatives, and reducing glass or plastic waste from packaging. 

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