Maximum Collagen Extraction

[scott123]

After simmering my chicken stock for 7 hours I still notice undissolved pieces of soft cartilage. I can squish them between my fingers but they aren't completely dissolved.

Soft cartilage is one of the primary sources for the collagen that makes soup gel, right?

If I want the thickest gel should I simmer it longer?

Also, although I've never seen a recipe adding salt to stock before you simmer it, has anyone ever tried it? In theory the salt should raise the boiling point and the collagen should melt faster. Besides that, I'm not sure what effect the salt would have.

[Suzanne]

It will help if you add some acid, such as white wine, but I don't think you are ever going to melt ALL the collagen. And seven hours on the first boil is more than you need -- 3 to 4 should be plenty; after that, you'll just be releasing more minuscule bits of protein into the water. Strain the stock and defat it. Make a second stock with the bones, etc. (this is remoullage -- reboiling the bones with more water and fresh aromatics), strain and defat that one, then combine the two stocks and reduce them. Reduction gives you a concentrated stock, one that will gel well.

The main reason NOT to add salt to the stock initially is that once you start reducing the stock, you will have no control over the saltiness. I doubt salt would make much difference to the temperature or the collagen extraction.

[dano1]

Like Suzanne said, simmer chix stock 3-4 hours tops and taste as you go. Stocks that simmer too long(yup, knew 1 chef who kept his garbage stock going 48hrs plus) will taste "muddy".
Chicken stock i will salt from the start. Something we are all told not to do but it does IMO give your stock a depth you will not acheive by salting at the end. Do not salt if reducing to glace. i do not salt any other stocks, veal, fish, etc...
Reduction is the key to a full bodied stock or sauce without resorting to artificial measures. A split veal foot never hurts either for those meat stocks .
Reduce, reduce, reduce.

hth, danny

[chef from va]

i am curently taking a class called soups stocks and sauces. textbook method of making stocks for us (which has yet to be proven wrong) says to boil for 1 hr and simmer for about 8 - overnight. we never add salt to our stocks because we use it in our sauce production and we dont want to have a salty flavor to start with. as dano1 said if you boil the stock for to long you will have a funny taste to it and it will also be cloudy. our teacher Chef Rerez has told us that it is ok to not disolve all of the connective tissue (collagen) as long as the stock is simmered long enough little bits dont hurt. reboiling the bines and adding that "weak stock" (after draining the bones and bits and peices) will also help to change every last little bit of collagen into gelatin. and be sure to skim the fat. like i said before we do this every class and we havent had any trouble with it at all.

[scott123]

From what I'm hearing, it sounds as though stockmaking is about body versus flavor. The longer you simmer the more collagen (body) you get but the flavor gets muddied. So you end up with a compromise - long enough to get a good amount of collagen but short enough to keep the flavor intact.

If one were to have a lot of time on their hands couldn't a better stock be made by separating the soft cartilage from the other bones and simmering them separately - the flavorless cartilage for a very long time and the flavor giving ingredients for only a couple of hours?

[dano1]

Scott, whatever you do,DO NOT BOILyour stock for an hour, unless it has been passed and you wish to reduce to demi, glace, or sauce. You WILL cloud it and find the taste unappetizing.
You do need the bits of flesh on the bones to give your stock flavor- along with mirepoix, sachet. The body is controlled by reduction after the initial stock is made-unless its fish or shellfish based. Reduction of these will increase flavor but there just isn't enough collegen there to tighten.
If you want to boil bones for collegen, your stock will taste like boiled bones -not very appetizing. One thing you can do to "fortify" the flavor of your stock is to make what used to be called a second stock or broth(not remoullaige). What this is are meat trimmings and more mirepoix added to a stock for more depth of flavor. The meat has only so much to give before becoming tired. Think along the lines of consomme here.
One thing to remember, and this appears to get lost nowdays, is that stock is just a vehicle, whether it be for soups or sauces. The "demi" this and "reduction" that abounds now on menus shows to me someone who has not grasped the concept of basic saucemaking. Ok enough of my rant .

hth, danny

p.s. ohh always skim as your stock comes up. The proteins are good for beer but not stocks.
l

[soussweets]

three hours is plenty of time to release all of the collagen in your chicken as long as its well quartered. for max colagen release, start your stock in a pot of ice water, the slower you bring it up to a simmer, the more time you have for all the good stuff to release from the chix. start slow, once u simmer, keep it on a slow roll. then u have the option of a remulage( never have the time for that myself- i only use this method when dealing with veal or larger bones) strain, shinois and reduce till your hearts content. chicken glace de viande is a beautiful thing with some fresh herbs and a little butter mounted in.

[scott123]

If you want to boil bones for collegen, your stock will taste like boiled bones

I think you might have misunderstood me. Soft cartilage, as far as I know, has no flavor. The bones would be included in the short term (2 hours) flavor-producing pot. The soft cartilage would go in the long term (8 hours) body-producing pot.

Although I appreciate everyone's kind advice, I think I should be clear that I have no intention of simmering my stocks for less than 7 hours. My initial question was as to whether or not to simmer it for longer, not shorter. I adore cloudy stocks. My goal is not clearer stocks but maximum collagen extraction.

[Suzanne]

Okay, Scott, we got you. I'm not sure I understand why you don't mind that your stocks are cloudy, but if that's all right with you, so be it. Really, though, 7 hours is excessive for chicken. Just once, try it our way: simmer 3 hours, strain and make a second stock with fresh cold water and the bones, then combine the two stocks and reduce them.

Here's why: I believe that what you're looking for has nothing to do with time, but everything to do with saturation. That is, the water may have absorbed as much of the protein of the collagen as it can hold; longer cooking will have no effect because the water cannot accept any more protein. That's why we make the "second stock" -- to allow more of the collagen protein to be absorbed into the new water. Then by combining the two stocks and reducing them, we evaporate out the extra water and keep the dissolved proteins.

So you see, it makes much more sense to make two stocks, combine them and reduce them. However, if you are dead set on cooking your chix stock that long: remember that it is possible to burn your stock by overcooking it. The stuff that sinks to the bottom of the pot can burn on, and the film that collects around the sides as the stock reduces can burn. These will give your stock an off-taste. Are you transferring everything to smaller stockpots during the simmering marathon? You should, and you certainly should whenever you reduce stocks.

If you want to experiment with removing the cartilage and boiling it separately, I'd be very interested to hear what happens. Please do let us know how that works, how the end products compare in taste, and all that other good information. (Of course, you could probably get the same effect by adding some commercial gelatin to your stock, but that would be cheating. )

[scott123]

I'm not sure I understand why you don't mind that your stocks are cloudy

Maybe I'm in the minority here, but I've always believed that stocks should be cloudy/hearty and broths clear/delicate.

Of course, you could probably get the same effect by adding some commercial gelatin to your stock, but that would be cheating.

I've thought about that *S* Is unflavored gelatin really flavorless? If it isn't, I'd hate something that would alter the flavor of my stock. I guess the only way of knowing if it's flavorless is to make some up and taste it.

The idea of the stock being too saturated to accept any more protein is certainly an interesting one. I have to admit that I do a sort of quick second stock just to rinse out the post strained bones. I could shorten the time on my first stock and lengthen the time on my second. My only concern is that, if the remoulage is simmered for an hour or more I would definitely want to chill the first stock during that time.

Suzanne, how long do you simmer your remoullage? Do you chill your first stock while your remoulage is simmering?

[thebighat]

Anybody read Escoffier anymore?

[dano1]

Who?
lol....not in years...Next time a make espagnole i must track down partridge and bayonne ham .
sorry off topic, danny

[Suzanne]

Originally posted by scott123
. . .
Is unflavored gelatin really flavorless? If it isn't, I'd hate something that would alter the flavor of my stock. I guess the only way of knowing if it's flavorless is to make some up and taste it.

. . .
Suzanne, how long do you simmer your remoullage? Do you chill your first stock while your remoulage is simmering?

Gelatin sheets are pretty much flavorless. I can't say the same for granulated stuff like Knox; that has a vile taste, IMO. But unless your stock is really delicate, it might not be noticeable. It also depends on what you're going to use the stock for. If it will be the basis for a soup, and you just want the gelatin for body, the flavor change might not matter. If you want to use it for jellied consomme, though, you don't want to use a gelatin that imparts any flavor. If it's for aspic, well then you need to clarify your stock anyway as well as add gelatin.

I usually simmer the second boil for about half the time of the first (at least, for chix). And yes, I chill the first during that period for a couple of reasons:
1. safety
2. ease of de-fatting, because I don't always manage to skim off all the fat as it's simmering.
Then I combine the two and reduce the whole thing.

[phatch]

Why wouldn't you just start the first batch on its reductive way while you simmer the second, then combine during the reduction? Doesn't seem worth the time or effort to chill if you can reduce away some of the extra liquid. Unless, I suppose, for defatting?

I'm no pro.

Phil

[chef from va]

i have to agree with suzanne on the cooling of a stock. i find that although it does take alot more time than skimming it allows you to remove more of the fat while maximizing the amount of stock you are left with.

as far as gelatin is concerned again i have to agree with suzanne. the sheets have little if any flavor and the powder is NASTY tasting.

i just made chicken stock today and i contemplated this thread while i was doing it. i thought of how you had said you wanted to maximize the collagen extraction. as i was cooling the stock for storage i noticed that it geled nicely. there was no additional gelatin added. just chicken bones (roasted, and the pan deglazed with remoulage), white meripoix, boquet garni, and enough water to cover.

not to sound like a smart alleck but how close to straight gelatin are you looking for?