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Hot filling
Also known as: hot fill, hot filling, hot-fill pouch, hot fill packaging, hot fill and hold
Hot filling packs a product while it is still hot, typically around 80–95 °C, and seals it at once to reduce microbial risk.
Hot filling is a process in which a product is filled into its pack while still hot, typically around 80–95 °C, and sealed immediately. The hot product also heats the pack's inner surface, reducing microbial risk. Jams, sauces, ketchup, fruit purées, soups and some drinks are commonly hot filled.
How it works
After heat treatment the product goes straight to filling, the pouch is sealed, often held or inverted briefly so the hot product contacts the closure, then cooled. Hot filling is typically suited to acidic products; low-acid foods usually need a higher-temperature process such as retort. The food business is responsible for validating the process.
What the pack must handle
- A heat-resistant sealant such as suitable PE grades or CPP
- Adhesives rated for temperature, to avoid delamination
- Strong seals and dimensional stability while hot
- Food contact compliance tested at the fill temperature
Spouted pouches and stand-up pouches are common hot-fill formats, and caps must also tolerate the heat. Give your converter the actual fill temperature in degrees, then run real-product trials on your line and check sealed samples after a few weeks of storage.
Frequently asked
What temperature is hot filling?
Typically around 80–95 °C, depending on the product and process validated by the food manufacturer.
Why do hot-filled pouches look slightly shrunk?
As the product cools its volume drops and a slight vacuum forms inside, which pulls the film inward; this is normal if seals stay intact.
Related terms
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