Bechamel Question: Milk Fat Content

[Porthos]

For reasons that are not important here we have changed from using 2% milk to 1% milk in our household. When making a basic bechamel it is my understanding that the thickening comes from the the denaturing of the proteins in the flour in the roux. I am a bit comfused because with the 1% milk the finished sauce is a bit looser than I am used to. Since I have been making bechamel sauce since about 1969 I am very familiar with varying the flour content to control just how tight the sauce becomes and have continued using the proportions that I've used for decades. Does the milk fat content play into how the sauce thickens? Or is it something to do with the flour I currently have in the pantry?

[Deryn]

The more fat in the milk, the thicker the sauce will be in my experience. I generally vary the liquid amount to get the thickness I want though, not the flour - but then I don't use a recipe either.

[Shel_B]

Porthos ... my experience is that a fuller fat milk will provide a tighter sauce, all else being equal.

[Thanks for the Crepes]

I get good results from everything with 2 percent milk, including bechamel. We don't really even notice it compared to whole 4 percent full-fat milk.

 

When I try to drop below that, I'm never satisfied.

 

I don't keep cream, ever. Our household can't afford the calories, saturated fat and cholesterol.

 

I make scalloped potatoes, spinach/artichoke dip and alfredo sauce that are very lovely and decadent to us with 2 percent milk, and butter, thickened with flour. This is all with 2 percent milk, but when I try to drop below that it just doesn't give acceptable results in anything.

 

There is, in my personal experience, a limit to austerity in this particular area.

 

However, if you and your family find lower fat milk acceptable to drink, for cereal, for baking, etc., then you may want to stick with that and just buy the 2 percent for those applications that you find actually require it.

[TheCulinaryLibrary]

Both fat and moisture (volume of liquid) effect the texture of sauces. More fat or less moisture =thicker sauces. By volume, milk is the primary ingredient in béchamel sauce. Butter is the primary fat ingredient. The difference in butterfat content between low fat (2%) and full fat (4%) milk, in itself, should not significantly effect the viscosity of the sauce, it does however effect both flavor and mouth feel and this could be what you are experiencing. There is a significant subjective difference in mouth feel (texture/thickness)  between low and full fat milk. Frost, et.al in ‘Food Quality and Preference’, 2001 confirmed that a combination of adding a non-fat thickener, whitener and cream aroma to low fat milk mimicks the sensory mouth feel of full fat milk. But if you want a thicker sauce you can always try:

Adding a little less milk when using low fat

Adding a little more flour and/or fat

Adding a few grains of calcium chloride to help “bind” the milk particles tighter. (Because it’s salty you’ll need to reduce added salt. Available for $5.99/50g @ modernist pantry.com )

Try thickening your sauce slower at a lower temperature as higher heat breaks the bonds between food particles making sauces ‘looser’.

[Porthos]

I found that increasing the flour to 2 1/2 tablespoons per cup got me back to the thickness I was looking for. Thanks for your answers and input.

[AlaMoi]

I've been using 1% milk and unsalted butter += parts AP flour for a long time with no complaints.

 

I have used 1% plus light cream later on for volume of a daughter type sauce - but the effect of the cream is not making the sauce thinner/thicker - it is as mentioned all about 'richness' and mouth feel.

[helenjp]

I read this with interest - Japan is undergoing yet another butter shortage...again...and I experimented with olive oil bechamel. It was considerably thinner, but interestingly, it was also less stable. When I added some powdered cheese to one portion of the sauce, it started to separate. I wonder whether milk fats/other milk solids behave differently from vegetable fats?

[Porthos]

I make my roux with olive oil quite often with very good results.

[helenjp]

Thanks. I was reasonably pleased with it too, and I now recall that I had a fair amount of onion in that sauce, which may have caused the stability problem. BTW I have made cream sauces with low-fat milk - here in Japan that's 1.2% milkfat.