Containers

The container and the fill

Updated October 2026

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Why fill temperature matters PET tops out low Hot-fill PET exists and is a different product Glass does not care Cold fill moves the problem to preservation Which closes the loop with the first section Oxygen over the shelf life Ask the supplier the temperature, not the category Vacuum is a design load, not a side effect References

A hot fill and a PET bottle is the commonest mismatch in this craft.

Why fill temperature matters

Hot filling is a preservation step: the product goes in hot enough to sanitise the headspace and the closure, then cools and pulls a vacuum. The container has to survive that.

PET tops out low

Our resin chart puts PET at a service range ending around 120F, which is well below a hot fill temperature. A standard PET bottle will distort.

Hot-fill PET exists and is a different product

Heat-set bottles with panels designed to absorb the vacuum. They are not the same as an ordinary PET bottle and they are not interchangeable with one.

Glass does not care

59 glass containers on this shelf. Glass handles a hot fill without comment, which is why the shelf-stable end of this category is traditionally glass.

Cold fill moves the problem to preservation

If the product goes in cold, the container is easy and the keeping quality has to come from somewhere else: treatment, acid, refrigeration or a short life.

Which closes the loop with the first section

The regime decides the preservation, the preservation decides the fill, and the fill decides the material. That chain is why the container is the last decision rather than the first.

Oxygen over the shelf life

A long-dated juice in PET sees more oxygen than the same juice in glass. For a three-day fresh product that is irrelevant and for a six-month one it is not.

Ask the supplier the temperature, not the category

Whether a specific bottle is rated for your fill temperature is a question with a number as its answer. "Food grade" does not address it at all.

Vacuum is a design load, not a side effect

A hot-filled container cools and pulls inward. Bottles built for it have vacuum panels to absorb that deliberately; an ordinary bottle absorbs it by deforming wherever it is weakest.

References

The Davis Pack Supply catalog, measured 18 October 2026. The beverages shelf is 558 rows: 305 containers and 253 closures, 246 PET and 59 glass, from 30 to 976 mL with a median of 118. No HDPE and no PP. The closures include 159 continuous thread, 27 spouted, 19 flip top and 18 lug and twist, and no crown finish anywhere on the shelf.

21 CFR 120.24, process controls for juice. A processor must use "control measures that will consistently produce, at a minimum, a 5 log (i.e., 10 5) reduction" in the pertinent microorganism, effective "for a period at least as long as the shelf life of the product when stored under normal and moderate abuse conditions", with the requirements met and "final product packaging within a single production facility operating under current good manufacturing practices". law.cornell.edu

Written from 21 CFR 120.24 and 101.17(g), and from the catalog as it stood on 18 October 2026. Whether a given product is a juice, an acidified food, a dietary supplement or an alcoholic beverage decides which regime applies, and that determination is specific to a formula and a label.