To be safe I just tossed some goose stock I made three weeks ago. What could realistically have been in it? [duplicate]

Question

I just realized that I forgot about the stock I made from the Christmas goose. I am aware that stock, especially made from poultry, is an excellent growth medium for all kinds of microorganisms, so I ended up tossing it (absolutely gutted though, it came out so good). Now my partner got annoyed with me for this and we ended up arguing about whether it would have been safe to consume after cooking the stock for a couple minutes before consumption. I did a lot of googling tonight, but I'm having difficulty providing her with references as to what kind of spoilage could exactly have happened (botulism, for example, apparently wouldn't have been a plausible issue given refrigeration and re-boiling). So maybe some of you can help me? Here's the key parameters:

The stock was prepared three weeks ago. It was reduced quite a lot and we ended up with two 13 oz glasses, one filled 90% of the way with a thick layer of fat on top, one filled 80% of the way with a slim layer of fat. The reduced stock was filled into the glasses at boiling temperature, and the glasses were closed immediately, left to cool for two hours in the kitchen and have since been in the fridge, which is at 7° Celsius (we were afraid the glass might burst from temperature shock when put directly into the fridge). The stock is very gelatinous (does that reduce water activity?). Pressure cooking the stock before consumption (rather than just boiling) would also have been an option.

Answer 1

Erring on the side of caution is probably always advisable, but I think in your case there would only be rancidity instead of microbial contamination. Since stock is at high temperatures for long periods of time, you can assume the solution is pasteurized and provided that the jars were properly cleaned and well sealed, bacteria shouldn't be a huge concern. Extended time in the fridge with a little bit of air in the top may lead to some off flavors, but all of this is pure speculation.

Whatever the condition of your stock, using it within a week or two is probably a good guideline since no one is perfect at cleaning jars or other kitchenware. It's also very important to keep in mind that food poisoning can arise from toxins that can carry over even after the pathogen has died or been inactivated.

To get a sense of how botulism works, see this WHO article:

https://www.who.int/news-room/fact-sheets/detail/botulism

Though spores of C. botulinum are heat-resistant, the toxin produced by >bacteria growing out of the spores under anaerobic conditions is destroyed by >boiling (for example, at internal temperature greater than 85 °C for 5 minutes >or longer). Therefore, ready-to-eat foods in low oxygen-packaging are more >frequently involved in cases of foodborne botulism.