Eggnog

Opened commercial eggnog keeps 3–5 days refrigerated; homemade eggnog keeps 2–4 days. Neither freezes well.

Keep it tightly capped on a cold shelf. Eggnog is rich in sugar, dairy fat, and egg protein, and it absorbs refrigerator odors quickly.

The commercial and homemade versions really are different products. Commercial eggnog is pasteurized, which is why it gets the longer window and why unopened cartons last until their printed date. Homemade eggnog made with raw eggs has had no kill step at all.

If you make eggnog at home, cook the egg base to 160°F — a stirred custard, essentially — then chill it rapidly. This is the USDA's recommendation and it eliminates the main risk. Alternatively, use pasteurized shell eggs or liquid egg product.

Alcohol is not a preservative at eggnog concentrations. Traditional aged eggnog recipes rely on much higher proportions than a typical drink contains, and are not a food safety strategy.

Eggnog combines raw egg, cream, milk, and sugar, which makes it one of the more hospitable things you can put in a refrigerator: high protein, high moisture, neutral pH, and abundant sugar.

The specific concern with homemade eggnog is Salmonella Enteritidis, which can be present inside an intact shell egg. Pooling a dozen raw eggs into a single bowl means one contaminated egg contaminates the entire batch, and the mixture then sits refrigerated for days — with sugar and dairy providing everything the bacteria need. That combination is why eggnog has a long history as an outbreak vehicle and why the USDA specifically recommends cooking the base to 160°F.

Commercial eggnog is pasteurized in the carton, so this risk is already handled. Its 3–5 day window after opening reflects ordinary dairy spoilage rather than anything egg-specific.

The signs of spoilage are the ones you would expect from dairy: a sour or sharply tangy smell, curdling or graininess that does not disappear when shaken, a thickened or ropy texture, and any mold at the neck of the carton.

Separation alone is not conclusive — eggnog settles, and a good shake resolves it. Curdling that persists after shaking does not.

Commercial eggnog carries a refrigerated "use by" or "best by" date while sealed. Once opened, use within 3–5 days (homemade 2–4 days) — do not stretch leftovers because the carton date is still a week away. Eggnog is a perishable dairy drink; when in doubt, discard it.