A bone tip is a point load on a film that's 0.065mm thick. When the chamber pulls to full vacuum, the atmosphere presses the pouch onto the product at roughly 10 tonnes per square metre. Something has to give, and it's the film. The pack looks perfect on the bench and it's loose by the morning.
Here's what stops it, in the order that costs least.
1. Cover the point
Most punctures come from one or two sharp spots: the cut end of a rib, the shank end of a leg, a chine bone left by the saw. Cover that spot and the rest of the bone is harmless. Bone guard pads exist for exactly this, or use a folded square of greaseproof paper, butcher's paper or a piece cut from a spare pouch. Lay it over the tip before the meat goes in the bag. It adds two seconds and saves the pack.
This works with the standard 65 micron pouch on most bone-in product. A whole chicken with the legs tied, a rack of lamb with the bones French-trimmed and covered, a bone-in pork loin.
2. Take the pressure off with a shorter cycle
A chamber machine pressing film onto a bone at 99.9% vacuum will find every point. On product that's going into a display fridge for a couple of days, you don't need that. Drop the vacuum setting to 95% and the film sits on the bone rather than being forced round it. You still get a tight pack, and the pouch survives. For long storage or ageing, keep the full vacuum and use one of the other methods.
3. Use a bigger pouch than you think
A pouch that's just big enough forces the film to stretch across the bone at an angle. A pouch with room lets it drape. Go up a width. A rack that fits a 250×350mm bag on the bench is better in a 300×400mm; a rib of beef that technically fits 300×400 wants 350×450mm. The extra costs a penny or two a pack.
4. Move to 130 micron
When the first three aren't enough, or when it's not worth the time to guard every bone on a busy Saturday, our 130 micron pouch is twice the thickness. A bone tip that goes through 65 micron film will usually press into 130 micron and stop. It's 18.8p a bag against 2.7p to 7p for the standard sizes, so it belongs on the product that's actually costing you packs, not on everything.
It comes in one size, 210×650mm, which is long and narrow on purpose. It takes a fore rib, a rack, a whole fish or a shank end to end, and if your chamber isn't 650mm deep you seal it in two passes: vacuum and seal with the open end on the bar and the far end folded, then turn it round. The 130 micron guide covers when it's worth it.
What doesn't work
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Cling film round the bone. It creases into hard ridges under vacuum and makes the puncture worse.
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Foil. Sharp edges of its own, and it's not what a customer wants to find inside a pack.
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Embossed bags. They're for edge sealers. In a chamber machine they seal fine but cost three times as much and the texture doesn't add puncture strength.
Check the pack before it goes in the fridge
Press the pouch. If the film is tight and the meat feels solid, it's sealed. If there's give, or you can see a small bubble tracking towards a bone, open it and repack now rather than find it tomorrow. A punctured vacuum pack is worse than no vacuum pack, because the meat sits in a sealed bag with air in it and the surface goes off faster.
Losing packs on one cut in particular? Tell us what it is when you request a free sample pack and we'll include a couple of 130 micron pouches to try against it.
