There are different kinds of spreads; these derive from
either animal fat or plant oil. What we refer to colloquially as butter is the
stuff churned from cow's milk, and it is 80 percent fat. Milk is churned, separating
the butterfat and buttermilk and the final product is tasty, but contains
cholesterol.
Margarine is not a dairy product. It's produced from
vegetable oils, and while margarine also has an 80 percent fat content, it
doesn't contain cholesterol.
Butter is made from animal milk and is a dairy product.
Margarine is made from vegetable oils, and is a vegetable product. Both butter
and margarine, in a pure state, are gluten free. But additives are deceiving,
so if you're buying butter or margarine, check the label.
Both butter and margarine are considered spreads. To market
these spreads as butter or margarine, they must contain 80 percent fat.
A spread that is neither butter nor margarine is usually a
plant-based choice, has no cholesterol and is lower in fats.
But spreads also contain more ingredients, such soy or
flavorings. They contain a combination of oils, with palm oil making a frequent
appearance. People with food allergies or sensitivities should note that these
substitutes might contain milk and/or soy, both common allergens.
When It Comes to Baking
The video "Butter vs I Can't Believe It's Not Butter in
Betty Crocker's Gluten Free Cookie Mix" demonstrates the difference
between butter and spread. The butter cookies had a better crumb than the
spread, and tasted richer.
But the competitor did well, making a good cookie without
milk fats. A lower fat spread though, with less vegetable oil content may not
perform well with this, or any, gluten free baking mix. The fat content was
very close in both products, but we see by the results that it isn't just how
much fat is called for, but the kind of fat we use.
Butter, though, contains cholesterol, and for this cook, that can be a problem. Testing the alternative spread in this mix I see there is a difference in the results. But as you can see in the pull-out, each cookie has 10 mg of cholesterol from the butter. The spread cookies may not be as rich and may crumble a bit, but I Can't Believe It's Not Butter makes a pretty good cookie.