Hexagonal Jam Jars

The hexagonal jar is the traditional preserve-shop jar. It became closely linked with British and European farm-shop jams, where the faceted shape signaled small-batch quality and stood apart from plain round commodity jars. The flat facets catch the light, are easy to grip and give a stable front panel for a label.

The tiny 28 ml and 41 ml sizes are a market of their own: they are the standard hotel, B&B and airline breakfast portion, and the same hex shape scaled down has become the go-to mini jar for wedding and event favors.

Hex jars are built around twist-off lug caps and hot filling, which makes them a natural fit for high-sugar, high-acid preserves that need a reliable vacuum seal. Marmalade, berry jams, lemon curd, honey and wholegrain mustard are the classic fills.

Because the empty jar already looks gift-worthy, brands use it for hampers and seasonal ranges, often dressing the lid with a gingham fabric cover and twine instead of, or alongside, a printed cap. Hospitality buyers order the mini sizes in volume for breakfast service.

The body is six flat panels rising to a rounded shoulder and a lug-finish neck. The facets are molded, so corner radii and panel flatness come from the tooling; crisper facets look sharper on shelf but need careful mold design to keep the wall even at the corners.

On a lug finish, angled threads on the glass engage the lugs on the cap. As the hot-filled jar cools and the headspace contracts, the cap is drawn down onto its plastisol gasket and the vacuum holds it closed.

Jams are typically hot-filled at around 82–85 °C, capped, and briefly inverted or steam-flushed to treat the underside of the cap before cooling sets the vacuum. Keep headspace consistent: too little and the cap can buckle, too much and the vacuum is weak. The faceted corners are the thinnest points, so avoid hard glass-to-glass contact on the line.

For fabric-top gift sets, the cloth is decoration only. The metal cap underneath makes the seal and goes on before the cover.

Larger hex jars are formed by press-and-blow and the small portion sizes by narrow-neck press-and-blow, which controls glass distribution and keeps them light. The hexagonal blank mold defines the facets before the final blow, and each jar is annealed and inspected, with particular attention to the sealing surface on the lug rim.

We supply caps in stock gold, black and white or printed with your design, plus labels, hot stamping and fabric-top gift dressing. Send us your fill volume and filling temperature and we’ll recommend the size, cap and liner.