Martha:
You picked a very difficult sausage to make at home, I think! A true "smoked polish sausage" has more of a cured sausage texture with a slight amount of smoke flavor and a golden-tan color. I am almost positive that this must be a cold-smoked product, done in a smoke-house at very low temperatures and relying on the salt/sodium nitrite cure for safety.
You would then take this "smoked" keilbasa and grill it before serving. We cook the storebought version regularly and also use the hot-dog sized versions on hot dog buns.
What you are describing is closer to a hot-smoked sausage where you start with raw, fresh sausage, cook it to a safe internal temp over a period of hours, and then eat it right away or freeze it. An example of this sort of thing would be cajun Andouille Sausage.
Most recipes for this sort of sausage that I have seen call for hot-smoking in the 190 - 220 degree range til you reach an internal temp of 160 degrees. Then, plunge the sausage in an ice bath to stop the cooking and quickly reduce the temperature before freezing.
The problem is that things like Andouille are supposed to have a nearly black shrivelled exterior. Smoked Keilbasa is not, but it is going to be unavoidable to get a safe internal temp. Smoking at 162-169 degrees, you'll take forever (if then) to reach an internal temp of 152 degrees.
I think the way to go would probably be to smoke them until they are the color you want, then put them in a steamer (or boil them) to finish cooking.
This is what the
www.sausagemaker.com has to say about smoking keilbasa:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>[qb]Sausage is placed in a preheated smokehouse at 130? F with dampers wide open. Keep this temperature until the casings are dry. Gradually increase temperature of smokehouse to 160-165? F with dampers 1/4 open. Apply heavy smoke and keep in smoker until the internal temperature reaches 152? F. If you are using a steam cabinet, remove the sausage from the smoker when it has an internal temperature of 135? F and cook in the steam cabinet to reach 152? F internally. Remove from smokehouse and shower with cold tap water until the internal temperature is reduced to 110? F Allow the sausage to hang at room temperature for about 30 minutes or until the desired bloom is obtained. Place in cooler at 38-40? F overnight.[/qb] <HR></BLOCKQUOTE>
The part about the steam cabinet acknowledges the problem you are having. That little note strikes me as the kind of thing that cookbooks love to throw in -- basically saying that, while they don't want to tell you their recipe won't work unless you do this, you have to do it or the recipe wont work!
You can't boil them first, because any moisture on the casing when they go into the smoker will make the casing hard.
On his website:
http://pages.cthome.net/edhome/sausage.htm
Ed Pawlowski describes the process as cold smoking at 90 degrees for four hours, then cranking up the heat to finish cooking them to 155 degrees before serving. He doesn't specify a heat for the this final stage, but I bet that it is pretty high (250) and done pretty quickly. This process strikes me as being the right way to go. What you buy in the stores looks like Ed's sausage at the end of the 4-hour 90-degree smoke.
Another option is make the fresh Keilbasa, hot smoke it at pretty high temperatures or even grill it quickly until it is cooked through, then eat it. I dunno. Like I said, that's a tough sausage to make at home.