To skim or not to skim (chicken stock / broth / soup)

[Jovidah]

It's in a lot of recipes but rarely properly explained... and whenever I don't do it I don't really notice what the big deal is. Urban myth, grain of truth? What's it all about? What's the result of doing it / omitting it?
Discuss!

 

[esoo]

My understanding is that it's protein and if you don't skim you'll get a cloudy stock.

I roast my bones and the use the slow cooker on low so don't get scum . It's a darker stock but I find more flavourful

 

[btbyrd]

The scum is mostly insoluble protein that flocks together and can make things cloudy. It also purportedly doesn't taste very good, though I've never really eaten it. As far as skimming goes, yes on a white stock, no on a brown stock. If I have a ton of time on my hands, I'll blanch the bones for the white stock, rinse them, and start over with fresh water. This reduces the amount of skimming needed and yields a cleaner stock. I almost never make white stocks though.

 

[blokey]

Skim or blanch, some of it are just disgusting. I like this technical a lot.

 

[Heckel7302]

You mean you don’t raft your consume at home?!?! You monster!

In all seriousness, I make stock in a pressure cooker. Never ever skim. Sure maybe it’s a little cloudy, but my family doesn’t complain.

 

[HumbleHomeCook]

The majority of the time I boil (to start) and don't skim. Double whammy.

If I'm wanting to make some nice Asian oriented broth for like ramen or something then I might be more particular.

 

[stringer]

I rarely make stock at home. Just me and my partner and Costco makes pretty good stock. But if I do, I always skim. But mostly to get rid of fat. Not as concerned about a cloudy stock. And I will strain all the bits out anyway so why bother skimming them. The fat will float to the top when you cool it. But I can't help myself ladling that stuff off while it simmers away.

 

[ian]

I do skim the scum. It's very satisfying.

With pressure cooker stocks, there's hardly any scum. Always wondered about that.

 

[Michi]

I do skim the scum. It's very satisfying.

Yep. The Zen of making stock…

 

[M1k3]

I do skim the scum. It's very satisfying.

With pressure cooker stocks, there's hardly any scum. Always wondered about that.

Probably less violent, less bubbling.

 

[knifeq2121]

always skim imo in pro kitchen. at home i used to never but recently been doing it too out of habit

 

[JASinIL2006]

I just made a ton of stock from 60 lbs. of beef bones. I always skim, both when making the stock and when reducing it to glace. Skimming gives you a much less cloudy and smoother stock. I think it improves taste, too.

 

[mengwong]

Probably less violent, less bubbling.

I’d guess a combination of factors in pressure cookers:

lower thermal gradient at the air-water interface
+
100% humidity
+
higher reaction temp denatures proteins further, diminishing gellable components. (This is why we avoid boiling-hot water when making gelatin)
=
absence of evaporative film “scum”

 

[Delat]

Funny, I just read an article on exactly this topic. They interviewed various chefs who all said it was purely for appearance.

I skim when I’m in the mood, which is about half the time. I don’t tend to make any clear soups or broths though, so they’re all destined to be cloudy anyway. On the rare occasions when I make a veloute-style soup then I always skim.

 

[Jeff]

It's in a lot of recipes but rarely properly explained... and whenever I don't do it I don't really notice what the big deal is. Urban myth, grain of truth? What's it all about? What's the result of doing it / omitting it?
Discuss!

My understanding is that it is about “clear” stock. and once the pot boils - it’s too late. It will be cloudy.

Not sure if that is correct but it seems to be my experience.

I detect no flavor difference, except perhaps my cloudy stock is a little heavier (more flavorful.)

I cook with a pentola. I skim the foam (It seems to make no difference)

Then when done, I lift the pentola out to dispose of the larger solids. Then strain through a chinois.

cool to room temp, stir then portion.

I store my stock in 16oz water bottles - in the freezer. 2 cups is a convenient size.

 

[Jeff]

It's in a lot of recipes but rarely properly explained... and whenever I don't do it I don't really notice what the big deal is. Urban myth, grain of truth? What's it all about? What's the result of doing it / omitting it?
Discuss!

As I watched Blokey’s video a question struck me- Is there a difference preparing beef or poultry stock?

I’m prepping chicken / turkey stock 90% of the time.

Are the principles & techniques the same?

 

[KnightKnightForever]

I skim every time

 

[esoo]

I would do beef the same as I do my chicken/turkey.

Set oven to 425
Roast chicken parts + 1/2 of aromatic veg for about 30-40 minutes to get nice and dark
Set oven to Slow Cooker Lo mode (190F)
Put roasted stuff, plus other half of aromatics in large oval Staub. Cover with water, add pinch salt, peppercorn, cloves, bay leaf.
Put in oven and let go for 12 hours (oven turns off at that point).

Strain through chinois, enjoy tasty stock.

Need to get a larger Staub (my large one is 6.75L) to make bigger batches.

 

[stringer]

As I watched Blokey’s video a question struck me- Is there a difference preparing beef or poultry stock?

I’m prepping chicken / turkey stock 90% of the time.

Are the principles & techniques the same?

I mostly roast bones or use bones from roasts for all my stocks. But there is such a thing as a white stock where you make it with raw or blanched bones. Usually poultry or seafood stocks but you could do a white beef stock if you wanted.

 

[boomchakabowwow]

bones, I usually do a pre-boil, get the scum floating and dump it all, rinse and start again with fresh clear water. what happens after that, I am never mad at.

I am okay, without skimming as well, if I dont care about having a clear broth.

 

[superworrier]

As I watched Blokey’s video a question struck me- Is there a difference preparing beef or poultry stock?

I’m prepping chicken / turkey stock 90% of the time.

Are the principles & techniques the same?

I think chicken is relatively cleaner naturally. Pork/beef seems to have a lot more scum and probably worse tasting scum

 

[More_Gyutos]

I always skim because I hear all my former chefs and sous in my ear. Even tomato sauce, braises etc. Plus it looks gross.

 

[Cliff]

I use a pressure cooker at home and let it fully depressurize on its own. Stock comes out clear. I think it's because it doesn't boil and churn the nasty stuff into emulsion.

 

[More_Gyutos]

I use a pressure cooker at home and let it fully depressurize on its own. Stock comes out clear. I think it's because it doesn't boil and churn the nasty stuff into emulsion.

No, it’s because it does. Boiling diffuses all of the scum and fat into the stock. It’s hiding there.

 

[Cliff]

From Serious Eats:

"An added plus: the contents of a pressure cooker go relatively undisturbed, since the liquid never effectively boils."

 

[More_Gyutos]

From Serious Eats:

"An added plus: the contents of a pressure cooker go relatively undisturbed, since the liquid never effectively boils."

Then why do I have scum on my walls when I use my pressure cooker?

 

[M1k3]

Then why do I have scum on my walls when I use my pressure cooker?

Turn the heat down.

 

[Cliff]

If you release pressure all at once, you will get a furious boil

 

[ian]

There can also be some scum on the walls without boiling, tho. I’ve noticed that.

@mengwong’s post above also seemed smart. Idk if scum actually breaks down at higher temps like he was suggesting, but that would explain some things, I guess. I always get scum on the sides of the pressure cooker (instant pot) near the evaporation line. Maybe that’s actually a cooler place, since the heating element is at the bottom, or…? Idk

 

[mengwong]

or…?

I’d guess — in addition to water-level evaporation rings — mechanical agitation (e.g. settling of contents & initial boiling prior to pressure seal) splashes fluid on the sides, which then dries.

Somebody is gonna have to sacrifice a GoPro for science. Maybe we can get Nathan Myhrvold to do it.