We all have those moments when, in search of that jar of pickles or maybe the curry paste, we unearth a container, deep in the back of our fridge, that was probably best left unearthed. Stratified, congealed, cloudy, and impossible to identify as what it once was. Those are the times when you skip the sniff test and throw the entire sealed container into the trash.
Or, if you're like me, you give it a little pat; say to yourself, It's not quite ready yet; and gently place it back in its corner, where it belongs.
You see, for the last year, I've had two quarts of my eggnog hanging out in the back corner of my fridge, waiting to be cracked open and tasted. That time has finally come.
I first heard about aged eggnog when Michael Ruhlman wrote about it on his blog back in 2008, but it didn't seem to become wildly popular until last year, when folks started recommending making your eggnog up to a year in advance, claiming that mellower, more complex flavor and richness would be the rewards you'd reap. Think of it as your past self leaving a little holiday gift for your future self, and the nice part is, your future self doesn't even have to send a thank-you card.
But here's the real question: Is aged eggnog all it's cracked up to be? Is it worth giving up fridge space for a year? Is it even better at all? I mean, I like cool things and fun experiments, but there has to be a reason to age eggnog beyond just the "it's cool!" factor, right?
Well, we tasted and found out.
You must be wondering: Is it safe? Statistically, about one in every 20,000 eggs sold in the US is contaminated with salmonella, so, assuming you're getting a random sample of eggs and using eight of them in a batch of nog, that's a .04% chance of being exposed. But eggnog contains booze, and booze kills bugs. How well? Very well.
A team of microbiologists at Rockefeller University, in what sounds like a late-night-at-the-holiday-party-inspired bit of good science, proved that, at least in lab conditions, given an alcohol content of 20%, eggnog comes out the other end completely sterile after just 24 hours of resting. That's cleaner than eggnog bought in sealed cartons from the supermarket.
Short answer: Yes, it's safe. At least, it's as safe as anything with a 20% booze content can be.
For my taste test, I set up a simple blind triangle test, in which I served nog in containers marked A, B, and C. In this case, container A held nog that had been aged for a year, while B and C both contained fresh nog. I vigorously shook each container to homogenize and froth the contents before serving, and I asked the tasters to taste all three before commenting. Tasters also tried them in random order (i.e., not everyone started with batch A). Right off the bat, it was abundantly clear that A was the outlier. Aging for a year makes a huge difference in flavor, and no tasters were confused by that. But was it a positive difference? Given all the hype for aged nog, I assumed it would be, but I was surprised to find that the exact opposite was the case. Tasters unanimously preferred the fresh stuff over the aged.
While fresh eggnog is simple, smooth, and, well, fresh-tasting, aged eggnog is much more aggressive. The booze comes out stronger, and there are medicinal, almost minty flavors that people will pick up on—almost as if you've spiked your eggnog with an herbal liqueur, like Fernet-Branca. Those flavors on their own are not bad. I quite enjoyed them, actually, but when coupled with the sharpness of the booze, they become overbearing.
I was a little surprised. The results of my taste test were in direct opposition to one conducted by the generally reliable Cook's Illustrated. They found, unanimously, that aged nog was mellower and smoother than fresh nog. Similarly, Alton Brown says that "the longer the nog ages, the more mellow it will get." In The Art of Eating, Holly Jennings found three-week nog to be "rounder, smoother, and noticeably more complex."
But then there are some outlying voices that agree with my findings. Boozenerds.com found that nog peaked at three weeks, then went downhill from there (the oldest they tasted was five weeks old, and it was described as "eggy" and "almost metallic"), while Julia Thiel of the Chicago Reader claimed that year-old nog had "more depth and complexity of flavor," but that "the booziness made it a little difficult to drink."
Thiel's assessment is most in agreement with my own. The nog was definitely more complex—new flavors had developed that are not present in fresh nog—but the booziness came strongly to the forefront.
So what accounts for the different results? The main thing seems to be age. All of the side-by-side blind taste tests I've seen have pitted nogs aged for just a few weeks against fresh nog. Those that claim that nog gets mellower continuously over time don't offer experimental data to back up those claims, and we all know how easily the human mind can trick itself without the benefit of blind tasting.*
*This all reminds me of a taste test I performed on aged whiskey, in which tasters who thought they were drinking older whiskeys ranked them better, even if the whiskeys were in fact younger or identical.
Cook's Illustrated also conducted its test quite differently, omitting the dairy from the aged nog and adding it just before serving, which could further skew the results. To be fair, my taste test also had a small sample size, only five tasters.
If I had planned better, I would have made batches of eggnog month to month throughout the whole year, week to week for the last two months, and day to day for the last two weeks. so that I could do a full blind taste test tracking changes over time. Unfortunately, I didn't, and it'll take me another full year if I want to try this out again. Such is the pace of good science.
But! Here's my request to all of you: Go out and make a batch of my eggnog sometime in the next couple of months (make sure to note the date!), save it in your fridge for the holidays, make up a fresh batch, then have your friends and family taste the two side by side (blind, of course!). I'll set up some kind of forum for us all to report back, and we'll see where that data takes us.
So Is It Worth It?
If I had to live in a world with only year-old nog and fresh nog, I'd pick the fresh. Fortunately, we don't live in such a world, and we can compromise. My favorite results of the night came from mixing the aged and fresh nogs, so that I could capitalize on the complex new flavors in the aged nog while toning down its harsh edges and booziness with the fresh. Cook's Illustrated was on to something when they suggested leaving the dairy out of the aging step.
You know how there are broiled-eel shops in Japan that have had the same pot of sauce simmering away for centuries, topping it up with fresh sauce daily but slowly letting it build up in complexity over time? I suggest that a bar with more space and commitment than I currently have (perhaps somewhere in Brooklyn or San Francisco) start up a never-ending eggnog barrel. Fill it halfway this year, let it rest for a year, top it up with fresh nog, and serve. Each year, pour only half of what's in the barrel, leaving the rest to age again until it can be re-topped and served again.
It'll make for some seriously good drinking. Or, at the very least, some seriously casual science.