I didn't think they were made literally in store, I did word it poorly though as I was half asleep and about to hop into bed.
I was speaking of the two for four packs you can get in their fridges.
Out of interest since you seem knowledgeable on the subject of sausage, do any of the supermarkets actually make their own (literally) in store?
No, there are no supermarkets that make their own in-store. It’s a local authority licensing issue. To make sausages you need to be a licenced meat processor and it’s just not cost-effective. Morrison’s do have their own slaughter facilities and they make most of their own pies, bacon, minced beef, lamb etc. all done in Morrison’s owned and operated factories.
Where local butchers really have a huge advantage is they are licenced to prepare meat and meat preparations (sausages etc.) and they can basically have stock recipes they always have in stock and then if they do have a bit of something excess, they can open their recipe book and make a limited run from it.
There are only really 3 big sausage factories in the UK, unsurprisingly owned by the three biggest pork producers (Cranswick, Tulip and Danish Crown) and they pack for all the retailers. Tesco Finest are made in a special factory in Norfolk. The meat that goes in varies - breed, outdoor bred (the pigs are born in an arc in a field and spend their first 8-10 weeks outdoors), outdoor reared (they grow to full slaughter weight outdoors - but they may not have been born outdoors), organic etc. but the processes are all pretty similar and the retailers put the work out to tender every 12-18 months and the suppliers bid to see who gets the business. This usually comes at the same time as a range refresh or a packaging change.
As has been said several times in this thread, if you want a particular sausage, speak to your butcher. Independent butchers not only make their own sausages but also retail other independent butchers’ sausages so if they don’t make what you want, they can probably get it in for you.
Supermarkets are great, they sell decent food and fairly cheaply. If you want something that is genuinely different and better though, it really has to come from a butchers. My own personal favourites are Cowman’s in Clitheroe and McCartney’s in Moira. Both make their own rusk and seasoning packs so you’re getting something truly unique.