What did I do wrong?

This entry was posted by on Sunday, 18 March, 2007 at

Maybe I can pull a jwz and ask my readers for help — cooking help! Perhaps even the Hacker Kitchen can advise me.

So there I was, making a simple hot salmon mousse, and the cookbook explains how to make a nice sauce to dribble over it:

Melt 2 Tbsp butter in a nonstick saucepan. Dilute 2 tsp cornstarch into 1/2 cup milk, then add gradually to the melted butter over low-medium heat, while stirring continuously. Add 1/2 cup dry white wine, salt, pepper, and continue to stir until sauce thickens. Remove it from the heat, stir in 2 beaten egg yolks and lemon rind gradually, whisking fast until the sauce is even and smooth. […]

Seems easy enough, doesn’t it? I melted the butter, then thoroughly mixed the cornstarch into some milk and added the milk to the butter. But when I added the wine — bam! Instant curdling. I ended up with a big lumpy, gooey mass in the middle of the sauce. I couldn’t tell if it was coagulated milk solids (reacting to the acidity of the wine), or if it was the cornstarch, or some combination of the two. I was so frustrated that I tossed the whole sauce, and repeated the whole experiment using skim milk (rather than whole milk). Exact same results. So I guess milkfat wasn’t coagulating; it must have been either the milk proteins or the cornstarch.

Mind you, I’m no spring chicken when it come to cornstarch. I remember my naive days of trying to mix cornstarch into a big bowl of soy sauce, and getting ‘clumps’, and then learning how to dissolve it first in a teeny bit of sauce. But this whole experience has bewildered me.

Cooks, what’s going on here?

5 Responses to “What did I do wrong?”

  1. Frances's Dad

    Our daughter was our expert cook, but we lost her. Ask your wife.

  2. mab

    Was the wine cold? Did you add it slowly? I’ve seen this in baking, & have speculated that it’s the temperature difference causing the butter to re-solidify. But that’s a SWAG.

  3. The wife was stumped as well when I showed her.

    And the wine was exactly room temperature (I had just opened it from the wine rack), and I did in fact add it slowly to the hot butter/milk/cornstarch liquid.

  4. mom

    Did you taste the wine? Was it OK? Remember that vinegar + milk = buttermilk (curdling) and old wine or bad wine goes to vinegar….

  5. This is a common problem. I assume this sauce was close to a Hollandaise?

    I will look into it- I recall from days when I had time to cook it from scratch NY Times recommends using a blender.