Technique question: fat vs butter

[phan1]

Well, I've been doing a lot of reading but not much cooking. One question I have is that there are a lot of professional recipes that call for straining out the fat that accumulates from the fluid when braising. This leads to a better, cleaner looking sauce. But then they finish it with butter! Wouldn't the butter muddy the sauce and have a tendency to rise to the top of the sauce just as animal fat would? Or is butter pretty different from animal fat?

There seems to be a consistent story of getting rid of animal fat but adding butter. I like butter, but I also like the flavor of animal fat too! I feel it's a shame to not use it, especially since it's already right there in the pan...

[TheSwede]

Butter is already an emulsion between water and fat (and some proteins etc). That is why it is pretty easy to emusify a piece of butter into a water based sauce. Theoretically (according to McGee) you could emulsify a piece of butter into ordinary tap water, as long as the water is warm, but not hotter than approx 50 C (if I remember correctly).

With enough viscosity in the sauce, you should be able to emusify back the coking fat too. I have a theory that it won't taste as smooth and (eh) buttery as with real butter, but who knows?

How about an experiment?

[jvalentino]

Wouldn't the butter muddy the sauce and have a tendency to rise to the top of the sauce just as animal fat would?

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Not if done correctly.

Too much fat will make the sauce greasy. Your usually skimming quite a bit of fat off and finishing with a couple Tbs of cold butter.

I skim the fat, then wisk in some cold butter. Be careful not to heat the sauce too high when adding the butter, or it could break, or "rise to the top", like what you just skimmed off.

[markk]

Because of butter's composition, as TheSwede said, it emulsifies into a sauce at the final stages of cooking merely from the whisking into the bubbling liquid.

If you wanted to re-incorporate the fat you skimmed off because you like its flavor, you'd have to use an agent such as flour to do so, the easiest way being to cook the fat and butter together first to make a roux, and then incorporate your braising liquid into it.

[mexigaf]

Because of butter's composition, as TheSwede said, it emulsifies into a sauce at the final stages of cooking merely from the whisking into the bubbling liquid.

If you wanted to re-incorporate the fat you skimmed off because you like its flavor, you'd have to use an agent such as flour to do so, the easiest way being to cook the fat and butter together first to make a roux, and then incorporate your braising liquid into it.

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Another interesting point would be that you can incorporate butter into a boiling liquid without breaking the sauce as long as the amount of butter is enough to cool the liquid significantly quick enough not to loose the emulsion. This is the technique used for Beurre Monte

[Qwerty]

There is actually a school of thought that says you should leave the fat in the sauce and boil the hell out of it to emulsify it into the sauce. You'd typically find that in, at least I'm imagining, old school French cooking. The reason you don't want the fat in the sauce is mainly an aesthetic one--though there is a certain amount of greasy mouth feel as well (but when properly emulsified it shouldn't feel greasy on the palate).

I've heard of chefs who actually allow the sauces to chill completely, scrape the fat layer off the top, then, when serving, whisk in the fat like we would normally mount with butter. The idea is that the animal/sauce fat has a lot of flavor associated with it and can be used to help thicken and fortify the sauce. It won't give you a clean, vibrant, crystal sauce, but if flavor is paramount and we aren't working at Ducasse or The French Laundry (or whatever) it's not actually a bad technique.

You can also boil the hell out of your sauces and jus to create the fence emulsion...works best for a la minute cooking as the fat will seperate out eventually.

But I assure you it is a real technique.

Butter is a unique fat for cooking. The reasons you whisk in a small amount at the end of a sauce are many--richness, smoothness, sheen, thickness and balance. Cold butter swirled in to a sauce will not break, and in fact, will stay emulsified. This allows the butter to give it's essence without a "greasy" feeling, more of a luxurious richness. Of course, if will eventually seperate out, which is why it is almost exclusively done at the end right before plating.

And yes, melting butter into water is a common technique. It's called buerre monte or buerre fondue, and is essentially melted butter that is kept in its emulsified state. Think of a classic buerre blanc sauce but with only water. It must be held at a warm temp. in order not to break. It si useful both as a gentle cooking medium (i.e. butter poached), an enricher (added as is to sauces or whatever) or to enrich garnishes and the like, not to mention as a sauce. Very useful.