Does a company like Heinz make their own? Is there some big company making all of the glass for everyone? Is there a bunch of mom-and-pop glassmaking operations producing them?
Saint-Gobain is one of the larger firms in the glass packaging industry.
There are numerous packaging companies that make glass and plastic containers for retail food companies.
As an aside, one of my clients is CSI.
Sounds cool, right?
Closure Systems International.
They are a division of Alcoa and make almost all of the plastic screw off bottle tops for Coca-Cola and Pepsi.
To answer more of the OP question, Heinz used to make their own glass and may still do so. Gallo does so today.
Many of the ‘mom & pop’ glass factories have been bought out - many by Ball, which sold out to Saint-Gobain. (3 generations of my family worked in one such factory)