Last week I posted on Twitter that leaving chicken stock (recipe below) out on the stovetop all week was fine and I got all kinds of mystified tweets about how could this possibly be safe.
It is, and it’s a great way to have stock on hand all week for a quick sauce, a poaching liquid, an instant soup, add it to a stir-fry and thicken with cornstarch. You don’t need to go through all the straining and storing and labeling of stock and cleaning a big heavy stock pot. I do like to strain it out of one pot into another to get the bones out of it, but even that’s not strictly necessary to have easy chicken stock available most days of the week. [Update 8/24/2011: I should have clarified, provided that you boil it for at least several minutes, but, according to an article in today's NYTimes by food science authority, even this is unwise. While simmering the stock will take care of bacteria, it does not kill spores, and it does not destabilize all toxins. So prudence suggests that if you leave the stock on the stove top to cool overnight, bring the stock to a simmer the next day, strain and cool it then. (I'd like also to note, that the idea for Harold's article came from me—and I'm glad for Harold's reporting, as ever.)]
I’ll address the bacteria issues then describe how I personally make small batches of stock all year long using the leftover carcass from a roasted chicken dinner, which I do about once a week. (You should too, Russ Parsons!)
People are unnecessarily afraid of bacteria. Once your stock is cooked, it’s safe to eat. If there was bad bacteria in it, you’d have killed it. Let it cool uncovered (the faster the better; don't fear bacteria but don't give them the upper hand). Leave the pot out on the stove top (covered or uncovered once it's cooled, doesn’t really matter). Bring it up to a simmer for 10 minutes or so the next day and any bacteria that landed there and began to mulitply (and they multiply with astonishing speed at 90 to 110 degrees F.) will be dispatched well before the stock hits a simmer. [Again, as the article mentioned above notes, and as a commenter below notes, this leaves the possibility for heat stable toxins to develop.]
The only issue in leaving stock out all week is flavor. During the winter, our kitchen is cool. In the summer when it’s hot, I can’t leave the stock out because bacteria makes it sour. They don’t make it harmful. I would not leave it out for a week cold and eat it without reheating it. The following are recipe and pix of how I make small batches of chicken stock all year long. It take minutes of actual labor, not hours. Having Made And Consumed the The World’s Most Difficult Chicken Recipehere's what you do:
Easy Chicken Stock
- Chicken bones and scraps from the devoured chicken
- 1 onion chopped
- 1 or 2 carrots chopped (I peel them for photos!)
- 1 bay leaf
- 1 teaspoon black peppercorns, cracked
- optional: tablespoon tomato paste, garlic, thyme
- Combine all ingredients in a 2 quart pot cover with water, and cook over low heat (no bubbles, 180 degrees F/82 degrees C is ideal) for 4 to 6 hours or bring to a simmer and put it in a low oven (below 200 degrees F/93 degrees C) for 4 to 6 hours (I sometimes just leave it in overnight).
- If you want to strain it, strain it. If you want to skim the fat off the top, fine. If you don’t, don’t.
- Bring to a simmer before using; if not using the next day bring it to a simmer, allow it to cool and refrigerate it.
The following are pix from start to finished stock:
UPDATE 4/8/11: After an email exchange with a commenter, a large-animal veterinarian who wishes to remain anonymous, I'm adding information on bacteria for those who want it. I stand by all of the above, and I left Monday's chicken stock on the stove to cool overnight and didn't get around to finishing it till 4 the next day. I honestly think it's highly unlikely that it's unsafe, so unlikely that I won't hesitate to feed my kids chicken soup tonight, but it is possible that bacteria could be introduced to such a stock, two of which could potentially grow and create enough heat-stable toxin to make you ill. When I emailed the vet that it was more dangerous to drive a car than leave a stock pot out at room temperature (which it is), she advised me to wear a seat belt. Which I do. Also I refrigerated my stock when it was done in a quart deli container. While I don't think anyone is going to stir their stock with a toothbrush or pick their nose over it, then leave the stock out for several days, it would indeed be irresponsible of me not to convey as much info as possible about this issue for people who have concerns. Staphylococcus aureos is a common bacterium found on skin and in noses, where it is harmless, but it can, in the wet warm protein conditions of stock, generate a heat-stable toxin that could make you very, very uncomfortable. And there is a type of E. coli, unrelated to the nasty 0157:H7, that can generate a toxin that can give you diarrhea, which is no fun, especially if you are dining at Paul Bocuse (which happened to me this winter, almost certainly froom food poisoning). And if you want to get really paranoid about things keep the handy chart at the bottom of this link taped to your refrigerator. If you liked this post on chicken stock, check out these other links:
- The New York Times shares a recipe for Pressure Cooked Chicken Stock
- Here is a Matzo Ball Soup recipe from the Smitten Kitchen
- Here's the 2-quart All-Clad sauce pan I use here.
- Examines starting temperatures, stock clarity, protein density and more in this kitchen science article by CIA Chef Tucker Bunch.
- Here's more info on the All-Strain cloths and Dalton-Ruhlman cooking tools.
- © 2011 Michael Ruhlman. Photo © 2011 Donna Turner-Ruhlman. All rights reserved.