Dear Franco,
Interesting post. I'm not sure I correctly understand what cream liqueur is but I assumed it was the class of drinks like Bailey's Irish Cream etc. If not, you can probably ignore what comes next.
Like Simon I haven't found any scientific masterpieces yet, however I found a couple of perhaps related links via google for which I enclose the relevant chunks below. As you can see they are unfortunately not in total agreement with each other however the content might be of some interest.
(1) There is a second class of liqueurs that bears some consideration - cream liqueurs and egg liqueurs. Despite alcohol's great disinfectant properties, every liqueur book I've ever read cautions people against trying to keep cream or egg liqueurs for more than a few weeks to a month, and then only in the refrigerator. rced to make the same recommendation. Even with the alcohol, treat it like fresh milk or fresh eggs. If you would throw out milk that had been in your fridge for that long, you should throw out your liqueurs. So these should be made immediately before they are to be consumed. It is perhaps possible to keep cream liqueurs longer, but in order to experimentally determine how long they can last, I would be required to, on at least one occasion, consume spoiled cream or egg liqueur. And that I have no strong urge to do.
Again, commercial liqueurs last considerably longer. Eierlikör and Bailey's Irish Cream both have much longer shelf life than four weeks. But it is because they know what they're doing that they can get long shelf lives. As long as we're just puttering in our kitchens, we should be a good bit more careful.
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(2) As oddball as sone of the ingredients sound, This is better than most of the off-brand "Bailey's" imitators out there. For those of you worried about the raw eggs in the recipe, the alcohol in the whiskey does in any bacteria, as well as preserves the mixture. Keep refrigerated.
The links are-
http://www.guntheran...urs/storage.htm
http://everything2.c...eys Irish Cream
I didn't pursue any further in case I had misunderstood yr requirement. If not I will search a bit more although I wouldn't put yr hopes too high.
Rgds / Charles.C
