Is my crab stock safe to use?
Last night, we steamed a couple of live Dungeness crabs. After dinner, I made stock with the crab shells, strained it into a bowl, and cooled the bowl of stock in some ice water. Unfortunately, I forgot to put it in the refrigerator before I went to bed and left the bowl out all night. Do you think it's still safe to eat? The house was probably anywhere from 50 to 60 degrees (the heat wasn't turned on). It was left out for about 9 hours before I realized what I had done. I immediately put it in the refrigerator this morning. I really want to be able to save it because it was very tasty. But am I taking a big chance if I use it? I know that chicken stock might not be safe to eat, but maybe seafood stock is different? What if I bring it back to a boil?
Thanks for your advice!
Assuming you boil it for at least 10 minutes before eating, your biggest risk is staph toxin (not the bacteria itself) which is heat-stable. How likely it is that your stock has been infected with staph is dependent upon the environment (is anyone coughing or sneezing nearby? was it covered all night? did you stick a finger or used spoon in the stock?) Do not eat it without boiling it for 10 minutes first.
If you are not physically healthy, you should throw it out.
If the intent was to serve it to other people and you are not willing or able to guinea-pig it on yourself 12 hours beforehand, you should throw it out.
If it tastes or smells bad or off, you should throw it out.
If you are not willing to risk 6-48 hours of cramping, vomiting, and diarrhea for delicious crab broth, I would throw it out.
Lots of people will tell you it's probably OK. On the other hand...
It's not only bacteria that make you sick -- it's the waste they produce, which is not killed by boiling. Not to mention that these things can make your stock taste bad, negating the reason you wanted to keep it.
You left it out for far more than the 4-hour window of safety. I don't think any potential tradeoff in good flavor is worth the risk.
There's no real difference between chicken or any other stock, as you started with something sterile. Stock goes bad far, far quicker than meat -- sometimes as quickly as two days in the fridge. I wouldn't even think twice about throwing it out.