At least we’re in agreement, then, that I spelt it correctly. 
Ground beef + tomato sauce is called “ragu” in Italy.
Bosda’s Rule Of Thumb–if you gotta ask, pitch it!
This kinda follows the recipes I’ve seen. I was slightly mistaken saying ground beef. Pork and beef are used (or just beef or even just pork.) Milk is added and boiled down before the tomatoes. I’ve always used ground meat, although I’ve also seen recipes using minced meat (which really is not all that different than ground.)
At any rate, I’ve never seen sausage used in a Bolognese. (Although, honestly, I wouldn’t say you couldn’t use sausage, because sausage is essentially just spiced ground pork/beef/veal/etc.)
Twelve day old MEAT sauce? I’m glad you pitched it, and I wasn’t even invited for dinner.
In my experience, the way spaghetti sauce goes bad first is mold, and you can see mold. I find that it generally molds after about a week or two, but before then, if I can’t see anything growing, I eat it. If I do see anything growing, of course, I toss it out.
But then, IANAMB, and I rarely cook for anyone other than myself, so don’t take my word on it.
What about pickled herring? How long can one keep that in the fridge?
Oddly enough, I’d have said quite the opposite; seems like these threads pop up quite frequently and (from my POV, admittedly toward one extreme of the scale - having been trained in food hygiene for a catering role) I’m usually taken aback by the number of laissez-faire comments and advice based on very limited samples of anecdotes.
In terms of general dissemination and consensus of information, I’d say that food hygiene is the SDMB’s weakest topic (weakest I’ve yet come across, anyway).
I hear you, but lacking microscopic vision, I wonder how virulent the bacterial nasties could be without my even being aware of it. What I can’t see might hurt me.
Tenar, send me your mailing address. I have a gift waiting for you. 
Mmmmmm! I just had home made bolognese tonight. Pancetta, ground beef, ground veal, ground pork, tomatos, carrots… Cooks for hours. Add cream in the last 5 minutes and serve with fresh, imported Parmesean. My wife is SO awesome!!! 
Carnac, any chance of posting the recipe for this wonderful sauce?
So your name is really a misnomer, huh?
Why not? The mods will forgive, once they taste this dynamite family secret.
Saute a chopped onion in a fair amount of EV olive oil, say 5-6 T, until transluscent. Don’t skimp of the EVOO. Add 1 medium can of what Yanks call tomato sauce, such as Hunt’s. (Stop wrinkling your nose.) Add maybe 1/2 teasp. of dried basil and 1/2 teasp. of fresh rosemary, though dried will suffice. Add 1 clove garlic, smashed. No more. Reduce on low flame/heat for 1 hour, stirring a couple time. Obviously, leave the lid OFF and easy on the heat. Add a twist or two from the pepper grinder.
The resulting reduction will result in a surprisingly complex sauce so good you’ll want to have some bread handy. Trust me on this. If you want meat in it, saute it in onions separately.
I could teach you more, my young Jedi, but you’d just get into trouble with the women. Baby steps. Baby steps.