OK. This got me thinking about Knorr Stock Pots. I don't expect you use them but for beef stock they are brilliant (its not as if I can really make beef stock very often at home). How come they keep so long? There are no preservatives listed in the ingredients unless you count glucose. It says they keep up to 3 days in the fridge once opened. But they keep for months otherwise.In the fridge I would not keep it more than 72 hours and that's if you cool it within a hour and a half
Freezing it in ice cube trays is a good idea and you can reduce the stock first
Ingredients:
Concentrated Beef Stock (Water, Beef Extract) (39%), Glucose Syrup, Salt, Beef Fat (5%), Flavourings, Yeast Extract, Carrots (1.8%), Potassium Chloride, Palm Oil, Caramel Syrup, Gelling Agents (Xanthan Gum, Locust Bean Gum), Sugar, Leek, Parsley, Maltodextrin, Lovage Root