Is it true that simmering a cream sauce (with heavy cream) causes it to thicken - without using flour?

Question

I wasn't sure because I thought I'd heard that you take the pot off the heat before you add cream to a sauce, and then warm through, without boiling? I don't know which is true - boil to thicken or don't boil at all?

If anyone has a good recipe for a sauce like that, I'd appreciate it. I'm thinking (for starters)sauteed garlic and shallots in butter, add chicken stock, heavy cream, parmesan.

Answer 1

This is the way that Alfredo Sauce is made.  This thickening method is called a "cream reduction"  Make sure that your heavy cream is a least 35 to 40% fat.  Otherwise, it won't thicken much.

Here is a recipe I found online:

Alfredo Sauce

Ingredients

    * 1¾ cups (400 ml) heavy cream

    * 6 tbs. unsalted butter

    * 8.5 ounces (240 grams) grated Parmesan cheese or Asiago cheese

    * 1 tsp. salt

    * fresh-ground black pepper

    * pinch of fresh-ground nutmeg

Preparation

   1. Combine 1¼ cups (300ml) cream and the butter in a saute pan large enough to accommodate the sauce and later the pound of pasta. Heat over a low flame, stirring frequently, until the butter is melted and the cream comes to a bare simmer. Remove the pan from the heat once the butter is evenly incorporated into the cream.

   2. Cook the pasta, draining it a little before it reaches the al dente stage. The pasta should be slightly undercooked before being added to the sauce because it will continue to cook while the sauce is being finished.

   3. Drain the pasta and add it to the pan, along with the remaining ½ cup (100ml) of cream, the cheese, the salt, the nutmeg, and several grinds of the pepper mill.

   4. Heat the pasta and sauce over a low flame, tossing continuously, until the cheese melts into the sauce and the sauce thickens slightly, about 1 - 2 minutes.

Answer 2

it's called a reduction and cream naturaly has these properties do not boil only simmer itll be great add butter at the end.

Answer 3

You can simmer cream to thicken it because you will boil the moisture away, reducing the cream to butterfat, which is thicker than cream.  However, in most sauces you don't want to bring them to a boil because they include ingredients that will cause the cream or milk to curdle if it's boiled too hard.  Garlic would be one of these, because garlic juice is quite acidic.  If you want to simmer the cream to thicken it, make the cream reduction first and then add the other sauce ingredients afterwards, keeping the cream below a boil.

Answer 4

Yup, just make sure that you use heavy cream -- not half and half and not milk.  I tried yesterday w/ half and half and it was a mess of curdle.  If there isn't enough fat, the fat molecules of the milk-product will seperate.  So, heavy cream it is.

Start by doing the cream reduction.  Don't boil, but simmer.  Stir stir stir for however long it takes to slightly thicken.

In another pan, SWEAT the garlic and shallots in 1/2 oil 1/2 butter, on low-medium heat.  Once sweated, add them to your reducing cream, then a little chicken stock, then parm and let simmer even longer.

If you want to make a rue, add just a touch of flour to your sweating garlic and shallots and cook for 1-2 mins more.  

It'll only make your sauce thicker, which might be nice.

Answer 5

Yes, it does.  You are reducing the volume of the cream by evaporating the water out of it.  You cannot do this w/ milk-based sauces; they will curdle.

Answer 6

Sounds like a nice sauce. You don't need flour. Let it simmer, but not boil. If you need to thicken a bit, add a pat of butter.