I make a great eggnog concentrate that can be thinned out with either milk or whiskey for your personal drinking/sipping pleasure. I would like to can the concentrate so it will keep longer and I could then ship it to relatives who love it, but I'm worried about "cooking" my egg yolks and having the whole thing become a nasty curdled mess. How can I solve this without changing the basic yumminess?
In general it is not safe to can anything containing dairy or eggs. This is a fairly reputable canning site and it has some more information on safe canning practices and what cannot be canned: http://www.sbcanning.com/2011/11/what-food-and-ingredients-cant-be.html
Among the things listed as not safe to can:
Dairy: butter, milk, cheese, sour cream, cream (whipping or heavy), yogurt (greek or other), buttermilk, goat or any other animal milk, tofu, soy
Do not add: Oats, wheat, barley, grains, rice, bread, noodles or pasta, hominy, crackers, biscuits, pie dough, eggs
Sorry, but canning is not the way to go with this. Perhpas freezing it and then shipping in an insulated package with a cold-pack could work? Generally dairy and eggs (and even store-bought eggnog!) freezes really well :)
Besides simply being listed as unsafe to can (and there being good reasons for this), eggs and dairy are untested and as such (despite what you may find on pintrest/youtube) there is not any tested procedures to follow that would guarantee a safe product. Furthermore, the concentrate would be a low-acid food which means that it would have to either acidified (which would probably make it gross) to be waterbathed, or it would need to be pressure canned (which would certainly cook your eggs).