Where did my sauce go wrong?
Serious amateur here and I tried to make a pan sauce last night that separated. I am hoping you can tell me what I did wrong and why it is bad...
I pan seared some artic char and decided I want to do a sauce with lemon, white wine and capers. So after taking the fish out of the pan I added a 1/2C white wine and let it cook off for a minute or two, then added some shallot, garlic and capers plus a table spoon of butter. I let that cook for another minute or two stirring. Then I added lemon juice. It tasted great, but it looked a bit separated.
My theory is that either it was too much butter, or it was that I added lemon juice while it was still on the heat. Or maybe too much acidity?
The reason the sauce broke was the addition of lemon juice at the end.
Also, your sequence of building the sauce is off.
Generally, here's the way it goes. Deglaze with white wine (with a great bubbling up). Add small quantity of lemon juice and shallots and reduce to a few tablespoons. Throw in capers, and add salt and pepper, if desired. Take off heat, and add a pat of cold butter. Swirl around, and you will see the sauce thicken and
develop a sheen. Then it's ready. Adding lemon juice to a dairy/butter mixture will always make it separate. If interested, research how to make a beurre blanc, one of the greatest of all sauces, though of course, made with mmmm butter.
I have found that it is best to put the shallots, etc in first and let them get some of the flavor first then add the wine, reduce the heat after it cooks down, add lemon juice, etc.
then put the butter in last as all it needs to do is melt into the saue.
Kitchen gadget must is a whisk for any type of sauce making.
Are you trying to do a buttery lemon sauce, or a lemony butter sauce (a buerre blanc)? Very different things. To make a lemon beurre blanc, deglaze the pan with 1/4 c white wine and the shallots; cook until it is reduced to a few tablespoons and looks syrupy. Add 1/4 cup lemon juice, and repeat the process. Season lightly with salt and white pepper. Remove from the heat and stir in, a tablespoon at a time, about 4 T butter (half stick)--it will form a beautiful emulsion.
Incorporating butter into acid over heat, unless you do it very, very low in an already only warm pan, will result in a broken sauce.
You added the butter too early.
The typical sequence of events is sear the meat, put it off to the side to rest, deglaze the pan with whatever (white wine in your case), add aromatics and such, reduce for a bit, take it off heat, and then mount the reduction with butter, slowly and while whisking continuously.
As far as too much or too little butter, that's really more a question of taste than anything else. But you'll be much better able to determine when it's enough if you add very small pats, whisk until they have reverted to cream, and then decide whether to add more. For a very light sauce, a very small amount of butter (say 1/2 to 1 teaspoon) should be plenty. Another method of giving a fish sauce more body with less butter is to deglaze with fish stock (with or without the white wine). Anyways, the only thing you're doing with the butter is making it 'creamy'.
The idea is that the butter (in the presence of mostly water) reverts to cream, which gives the pan sauce a nice sheen and richness (after all, it's cream that it turns back into!). If that still doesn't do the trick you could always use a tiny bit of mustard as an emulsifier. But do be certain to add the butter *last*, right before serving, off heat.