seebee,
I think there are a couple of issues here. First, I don't remember seeing low-sodium versions of commercial sausages around, but I haven't really looked for them. I'm guessing they probably do exist. As was suggested above, a good place that makes sausage in-house will probably be happy to accomodate you with a custom batch, if the order size is adequate.
Secondly, the different between Polish and Italian is also an important distinction because in general terms, Polish are cured and Italian are fresh/raw. As such, the Polish relies far more heavily on (curing) salt as its identifying, distinguishing ingredient. I think it would be much easier to find lower salt Italian sausage because salt is mainly used as a seasoning in them. With Polish, while there are -- of course -- fresh varieties, the ones we commonly refer to as 'Polishes' in Chicago contain curing salt which, if omitted, would completely change the nature of the sausage.
I've been making sausage for about 5 years and it's really not a difficult thing to do. And I love being able to control not just the salt but all the ingredients that go into them. I try to use as little salt as I can without changing the profile of the product and generally speaking, the results have been very good. Even in cured sausages (that I end up cooking, like andouille, for example), I try to used as little curing salt as possible. With dry-cured, reducing the amount of curing salt can actually be dangerous, so I avoid doing so. But in many cases, going lower sodium is certainly do-able and the results actually help showcase the meat better. Ruhlman generally calls for 40g of kosher salt in a 5-pound batch of fresh sausage. I typically use about 30g -- which lines up with what some of my chef-friends do -- and find the results to be more to my liking.
As an aside, I think that more so than salt, fat is the most critical component in most encased sausages because without it, the sausages generally come out dry and crumbly. It is the fat in sausage -- and the proper emulsification of it during the process -- that give the final product the tight, moist and slightly spongy definition that makes it so satisfying to eat. But if you prefer less salt, reducing the amount of it in fresh sausage should not be a problem whatsoever.
=R=
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