How long will a drink with eggs and or milk really keep?

[cteavin]

Around October I made my first batch, spread over three bottles, of Aged Egg Nog. One was to sample week to week to get a feel for flavor and the other two were for the holiday -- it really does get better as it ages.  

 

The eggnog was such a success I've decided I have to have more. Of the recipes I started with was Alton Browns which said you could age it for a year, but every other recipe put a shelf life of at most two months in the fridge. Looking at recipes for Irish Cream I keep reading the same shelf life.  

 

I would think with the alcohol content high enough there would be no spoilage, even with raw egg yolks. Am I wrong in this assumption? Is there any science about how long something will keep in alcohol? In that past I've had Fruit Cakes, soaked in Navy Rum, that lasted years and were just as pleasant to eat after many years tucked away on grandma's pantry shelves. 

 

 

[weinoo]

Aged egg nog.

Aging eggnog for a few weeks sounds a little dicey. Aging it for a year sounds insane. The perishable parts of eggnog—milk, cream, eggs—could easily last a few weeks if properly refrigerated. But how many people have voluntarily consumed year-old milk and eggs?

 

A few, as it turns out—including Michael Ruhlman. Aged eggnog is nothing new (though most people don't wait an entire year to consume it). It's likely that back before modern technology, when hens didn't lay eggs in the winter, eggnog would have been made in the fall and then kept in a cool place until the holidays. George Washington reportedly created his own eggnog recipe involving rye whiskey, rum, and sherry, which he'd let sit for several days in a cool place. According to indepthinfo.com, it was "reputed to be a stiff drink that only the most courageous were willing to try." And many of the recipes for aged eggnog that have surfaced online date back to the late 19th and early 20th century. (Sadly, there were none in the old cookbooks I recently wrote about.)

 

[gfweb]

I recall Ruhlman's piece about it. Aside from the fact that year-old nog sounds disgusting there is certainly no data on safety.  Ruhlman in general takes a cavalier attitude toward food safety, leaving warm stock on the stove for days etc etc.

 

But it probably won't kill you.

 

And lots of people get sick over the holidays...why not one more reason?

[Ian Tuck]

Jeff Morgenthaler did it too. Now, I actually have a Campari bottle full of eggnog I made last Christmas (2013) in the fridge. It's the second of two bottles I made. The first one was horribly off when I tried it at about 8 months. It's quite possible that this one will be too. Jeff tweeted out a while back that he had some that was delicious. Perhaps my ABV wasn''t sufficient as a preservative.

[bostonapothecary]

I think some of the answers here are contained in another thread, but I can't remember where it is.

 

There are lots of commercial precedents for stabilized egg yolk liqueurs like advocaat and bombardino and I also did some exploring on the Bostonapothecary blog with Fluid Gels are Our Future: Fernet Bombardino, but I didn't get to take it as far as I wanted because of the expense. The secret is to low temp pasteurize the egg yolks into a gel, then shear thin the gel into alcohol to preserve it using a blender. Low alcohol percentages are not good at killing bacteria, unlike say 60%, but they do prevent bacterial growth and the magic number is 18% for the minimum of microbiological stability though I over shoot for 20% to err on the side of caution.
 

It is hard to say how sensitive these liqueurs are to oxidation, and in my experiments I vacuum de-gassed them, but these days I favor pressure de-aeration with my champagne bottle manifold because it works better, is cheaper, and uses beautiful bottles that are easy to serve from.

 

One of the stumbling blocks I couldn't develop a definitive best bet for was the thickening power of the yolks that sets in over time. The thickness on day one was very different than day seven. You could either add less egg yolks or you could re-shear-thin back to the original consistency. I was developing this as a way to batch flips and other high maintenance dessert drinks for high volume service or special events but I never really had to put it to the test.

 

Lots of potential here and I'll revisit it someday.

Edited January 2, 2015 by bostonapothecary (log)