The Substitute Teacher (Part One)

by Bridget Lancaster

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Thinking waaaaaaay back to my high school years, I recall two very different substitute teachers for my 10th grade chemistry class. One, whom I shall call "Ms. Fussbudget", was all business, no-nonsense, and picked up the lessons right where our regular teacher left off. The other, whom I'll call "Mr. Grumble", didn't much care what we did as long as we didn't set our desks on fire (don't ask.)

What's the point to my rambling? Well, by far one of the most frequent recipe questions that I'm asked starts something like, " Can I substitute "x" for "y"? Invariably I answer that you can pretty much substitute anything, but don't expect the same results (see Ms. Fussbudget and Mr. Grumble above.)

So are there hard and fast rules when it comes to substituting foods? Sorry, but no. However, by changing (not necessarily lowering) your expectations of the outcome, you can find success with many substitutions. In this post, we'll look at two of the most frequently requested substitutes, and what you should expect if making the change.

Butter – using salted instead of unsalted

Ok, I'll go ahead and let you know that I keep both kinds in my house. The salted butter I spread on my toast (or homemade waffles - yum.) But I, and the test kitchen use unsalted butter for everything else. There are a few reasons for this.

The amount of salt contained in a stick of butter is not regulated. So depending on the brand, the salt content can make up between 1.25 to 1.75% of the total weight. That's quite a range, and since we in the test kitchen love consistency with all of our hearts, it's better to start with unsalted butter and then give a specific amount of salt to use.

Salted butter also contains more water than unsalted butter, and while this might not make a difference when slathering a compound butter on your steaks, it can literally change the texture in baked good. We found that brownies and drop biscuits made with salted butter were pastier than those made with unsalted butter. I don't want pasty biscuits, do you?

So, if all you have in your fridge is salted butter and you're dying to make that batch of sugar cookies or crescent rolls, just know that they may come out a little heavy, and possibly a bit salty.

Dairy – How low can you go?

Of course we aren't going to tell you to ignore your health concerns, but know that swapping dairy products can have a huge impact on the resulting recipe. And the reason all comes down to the beautiful, misunderstood milk-fat. Fat gives custards richness, fat makes heavy cream whip to puffy perfection, and fat also prevents a "cream" sauce from breaking as it boils away. That's why the pan sauce made with milk will look split and greasy, while the one made with cream or even half and half will look, and feel silky smooth.

So here's what I suggest - if you want to reduce the amount of fat found in a recipe, or you just happen to be out of the dairy in question, only substitute similar ingredients (close in fat content) for each other. Here's a guideline:

Many cake recipes call for milk, and we've found that 2% or 1% milk will work just about as well as whole milk. Skim milk can be used, but know that the resulting cake will be slightly tougher and/or dry.

By and large we've had good luck when making custards and puddings with half and half instead of heavy cream. In fact, we often find the lighter result more enjoyable. Since custards don't come to a full rolling boil, there is no need to worry about the mixture splitting.

Be wary of using lower fat milks in custards. As they set up, the texture can be slippery and bouncy.

Soups, Sauces, and Casserole Fillings

Here's where it's easy to make a mistake. You want a "fill-in-the-blank" casserole that doesn't contain all of that fat! I understand, but don't pour in the half and half instead of the heavy cream. Here's why -

Half and half is homogenized to prevent the milk fats from rising to the top of the carton. While this process is helpful to prevent your morning coffee from receiving an unfortunate glob of fat, it's actually harmful to the ability of dairy proteins (casein) to coat the fat - which is necessary to prevent splitting as the sauce bubbles away.

Heavy cream is not homogenized, so if you wish to cut back on the fat in a casserole, just use ¼ cup heavy cream mixed with ¾ cup whole milk (that's for every cup of half and half used in the recipe.) This will give you a stable, and still pleasantly rich filling.

So that's the first installment of The Substitute Teacher. Next up - cooking (or not cooking) with wine and other alcohol. Stay tuned!

Have you ever substituted butter or dairy products with great, or not so great results?

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