How do supermarket "brands" come about?

[PiedNMash]

I was having a conversation with someone about their DC only liking branded food e.g. will only eat Heinz beans etc. I totally couldn't get my head round that. Why do kids care? Mine never get to see the tin TBH. I am interested in this for budgeting reasons.

Anyway. I always thought that big supermarkets hassled or negotiated with big companies to make their own house brands. Perhaps not the same recipe, perhaps slightly inferior, but this is how I thought it worked. So, for example. Heinz want Tesco to sell their beans. Tesco says OK, but you have to make XX tins under Tesco brand. Its kind of a win-win. I have never thought that Tesco have their own factory making their own beans. This has been my underlying reason for why I mostly buy non branded, but still good quality food. E.g. I'd never buy branded tin tomatoes unless a bargain and otherwise buy Waitrose only label tin toms as I'm sure they are as good, if not better.

So, I'm sure I am not right. Can anyone enlighten me as to what happens? I'm genuinely interested.

More likely than not it will be a third party manufacturer you've never heard of which makes the supermarket's own brand as well as stuff under brand names you'd recognise. An example is Northern Foods - it started out making M&S chilled stuff but is also the company behind Fox's Biscuits, Batchelors, and others.

Similarly Cranswick plc makes Weight Watchers pork products, but if you closely on the back of Lidl's Deluxe sausages you'll see that they're made by Cranswick too.