Puréed stock turns white???

2,485
492
Joined Oct 9, 2008
In another thread (https://cheftalk.com/threads/xanthan-gum-sauce-white.95382/#post-569344) I was struggling with xanthan gum. Now the mystery is deeper and more serious.

I made stock by roasting and then pressure-cooking a turkey carcass. Strained and chilled, it is medium-brown, mostly clear, and semi-gelatinous: it pours, but is definitely syrupy.

If I heat this to a simmer, remove from heat, and start puréeing with an immersion blender, it foams up creamy white almost immediately. Once foamy, it doesn't settle out without lots of time and fine straining.

Any theories?
 
4,276
1,164
Joined Dec 18, 2010
Air. Just like taffy goes white when air is introduced by pulling.

Does it return to brown after sitting?
 
2,485
492
Joined Oct 9, 2008
And I've never seen stock do this before.

NOTE: We moved about 7 months ago, including shifting from town/reservoir water to a well.
 
658
276
Joined Sep 26, 2017
Anyone have experience with hard water and the resultant soap residues? (My current theory...)

Hard water is not gonna do that to your stock. Air is the culprit like the others say.

To avoid the whole pot of stock turning white, you can just blend part of the stock with the xanthan gum to disperse it, and then stir that into the rest of the stock.
 
2,485
492
Joined Oct 9, 2008
Don't know if this will help, but when I puréed a block of the stock that I gelled lightly with agar, it did not foam or whiten.
 

pete

Moderator
Staff member
4,509
998
Joined Oct 7, 2001
Pat Pat said exactly what I was thinking-too much fat left in the stock.
 
2,485
492
Joined Oct 9, 2008
OK, an update. The stock was pretty clean, but the gum was very old. In addition, technique note: don't blend in xanthan gum if the stock is cold, or it will bind to the gelatin. Warm the stock until it's above about 80C and that problem goes away.
 
2,485
492
Joined Oct 9, 2008
The plot continues to thicken.

Made a brown turkey stock, mildly gelatinous, very little fat. Then I ice-filtered it: freeze solid, wrap in cheesecloth, allow to drain into a deep bowl very slowly in the refrigerator for 2-3 days. The result is essentially consomme: no noticeable gelatin in the mouthfeel, no fat whatever.

Heat to a strong simmer, insert immersion blender, and... creamy.

Yes, it's air. When I pour the stock into a big measuring cup and leave to stand, I can watch the foam slowly separate from the stock. Eventually, I skimmed off the foam and have perfectly clear (slightly xanthan-thickened) stock again.

But what on earth is making it do this? There's no fat, and very, very little gelatin. I could serve that stock as consomme and I assure you nobody would question that it had been expertly clarified.

I continue to believe that there is something in the water which is somehow causing this problem. Not that I think it's poisonous or something, but I would really like to know what's going on.
 
4,276
1,164
Joined Dec 18, 2010
I think you are overthinking this one. It’s the manipulation, not the water.

Thicken your gravy using a spoon, or gently with a whisk if you must.
 
2,485
492
Joined Oct 9, 2008
I think you are overthinking this one. It’s the manipulation, not the water.

Thicken your gravy using a spoon, or gently with a whisk if you must.
Wait--I thought xanthan gum had to be dispersed ultra-evenly, with a whisk at the very least. Not so? How do I avoid "dumplings"?
 
4,276
1,164
Joined Dec 18, 2010
Xanthan gum is not good for that application, as you are finding out. Thicken with a starch - flour, cornstarch, potato starch or arrowroot.
 
2,485
492
Joined Oct 9, 2008
Xanthan gum is not good for that application, as you are finding out. Thicken with a starch - flour, cornstarch, potato starch or arrowroot.
I'm lost. If xanthan gum isn't good for thickening liquids, what on Earth is it good for? Every source I've seen points to xanthan gum as an especially stable and easy-to-use thickener for sauces and the like. Now you say that's all wrong?
 
4,276
1,164
Joined Dec 18, 2010
Best for emulsions, like salad dressing. Not bad for sauces like Vierge. But not so much for gravy.

Others may have differing opinions. I’m mostly trying to help you grapple with your problem of air in your sauce.
 
658
276
Joined Sep 26, 2017
I use xanthan gum to stabilize whipped cream and to thicken gravies.

Are you using normal tap water? Where do you live? Maybe there's some kind of dissolved minerals in the water that create some chemical reactions?
 
Top Bottom