Boiling Chicken Stock
I make a lot of chicken stock at home, and I often find it at a full boil by the time I get back to turn it down. I lived beside a chef once, and he told me just a few bubbles every few seconds, the barest simmer possible.
So I'm curious, what happens when I make a mistake and it reaches a full boil?
I'm also terribly lazy, so when I make stock I often leave it on the stove until the next day, then boil it again...
Then leave it till the next day, then boil it again... etc. So when I bring it back to a boil, it often boils away for a few minutes before I get back to it.. again..
Other than perhaps clouding up the stock a bit with fine particles of chicken, is it hurting the flavour?
Boiling it tends to incorporate the fat into the stock - that's where the clouding really comes from. This makes it subject to going rancid, since it can't be thoroughly degreased.
I suffer from the same lazy tendencies myself - waiting for a pot to come JUST to a simmer is like watching paint dry, only less fun - and so I came to rely on my crock pot. Unfortunately, the older ones will STILL boil, even on the low setting, but at least it's not that mad seething boil that screws everything up. The newer ones have a non-boiling setting, and they're pretty cheap. Try Target or BB&B.
when you boil and reboil the stock, have you strained out the carcass and other bits?
I find that boiling too long produces a cloudy stock. Also, the mouth-feel is different. The boiled stock seems a little gritty on the tongue, at least that's the feel I get.
You should give it a try to see if you can taste the difference. What you can do is bring your water to a boil before adding the other ingredients. Next, just turn to the burner to low or medium-low to let the stock slow cook for a few hours. Another alternative is to use an oven-proof pot and put the stock in a 200F oven.
It's easy and you don't have to worry about the stock boiling off when cooking low and slow.
If you want to really remove the fat before reboiling to help clarify a little more, I would suggest tossing in a bunch of ice.
This will harden the fats and bring them to the surface and make it easier to skim and remove. Once skimmed, you can reboil to evaporate the added moisture.
OR, as noted by Thomas Keller, you can offset your stock pot on the burner, which helps create a convection and helps keep the impurities on one side of the pot so you can ladel out the clearer stock from the other side.
Just a couple suggestions.
You have been thorougly informed on the reasons why it is not a good idea to boil. But if you want to avoid the 'boil blues' again, get a crock pot/slow cooker. I am not a huge fan of the appliance over all, but stock is one thing it does brilliantly and, after making my chicken stock from scratch resolutely for years, I have gone the slow cooker route now.
Boiled stock isn't better or worse, it's just different. If you're looking for silky clear stock you can't boil it. But if you want something more unctuous and thicker, and don't mind cloudiness, boil away!