DRKsmoking
I really enjoyed your post, no matter how it turned out, the fantastic pictures and play by play of the process was a great read that will be useful and enjoyable to many!
I would throw out a couple points for you to consider for next time, which might be useful.
1. Sausage juiciness, and even flavor, is mostly tied to fat content. Its been proven over and over, you need 20 to 30% fat for a good tasting juicy sausage. Ground chicken has about 0% fat. Assuming your pork had 20% fat, your total was just 7.8% fat, not enough to give good juice or flavor. Much of the flavor is carried by fat. I would add 260 to 300 g of pork fat to your sausage myself, an additional 12 to 14%.
2. Water or liquid. Most sausages have 10% or more water added. In long slow smoke cooks like yours, most of it will be evaporated off during cook, so often folks will go 15% or more for that style of cook. The water does play a big role in perceived dryness, though fat content is usually what folks are describing as "juiciness". I would use 220ml water as a starting point for your recipe, so there would be some left after a 6 hr evaporation cook.
3. Texture-- I would NOT say you over mixed, per se, for a slow smoked sausage. But maybe that you're not clear on the target texture? Let me explain What I mean. Fresh sausages like brats or Italian, have a lightly bound looser texture than smoked sausage like kielbasa. That is totally intentional and comes from length of mixing, binder, and fat content. Your sausage texture looks exactly like what I would expect a slow smoked sausage to look like, a uniform solid mass that isn't semi-crumbly like a brat. It's perfect for your process. However, maybe in your mind you're thinking more of a fresh sausage brat-like texture? If that is the case, then just a quick mix with lower protein extraction, no NFDM binder, more fat, and a higher temp faster cook might give you the texture in mind? I'm just guessing what you're after based on your comments, but I personally like that sliceable texture you got! ;)
4. Binder. Thats a good bit of NFDM, which is used to lock the fat and water into bond with the proteins so it doesn't run out loose. Useful for high fat or liquid sausage and slow cooks, so fat doesnt render and moisture stays high. In your case, you had so little fat or moisture, that no binder was really needed, and you get the perception of dry with no juiciness.
With chicken sausage, the trick is to get enough fat and water into it and hold it, so I would use NFDM but it needs that 25% fat and 10% water to work with. And as said bybothers, you don't really need it with pork, though it is a nice insurance if your smoker temps get above 180 a bit.
Hope those comments are helpful to achieving the target sausage in mind! But I myself like the look of your product, and your rice dish is a great usage! Thanks again for your super enjoyable post and letting us be part of your cook, and journey--I love following along, and really appreciate it!