I oftentimes ship a sauce only sold in my area to family at different elevations. The problem is that the bottle it’s sold in isn’t very secure and many times it’ll break in transit and leak everywhere.
What should I look for when shopping for bottles/containers to use for shipping?
Plastic bottles will swell but not burst.
The problem is these were packed sterile, and if you repack it’ll let in germs and cause spoilage.
Could resterilize by repacking in heavy duty canning jars with as little air as possible and re-steam them.
Technically yes, but if this is a sauce that doesn’t need refrigeration (including after opening) anyway, just not as big of an issue.
Another comment had a great point that less product = more air = more sensitive to different air pressures. Ideally, the product is in a plastic bottle already and OP can squeeze a little out if needed, put the cap back on tightly with the bottle slightly squeezed, pack it safely, and send it off. If the lack of outside pressure is an issue, it’ll give the bottle a way to grow a little.
Source: I live in Denver and always have something (de-) pressurize when I go to/from sea level