If the recipe calls for butter solely as a flavor additive (using butter to flavor a piece of meat), then you might be okay. But if the butter is used as the "token fat" in a dish such as a cake and will affect the texture, a spread simply won't cut it. This is because spreads are more water and less fat when compared to butter.
Smart Balance is one option that comes to mind. If you read the label of this product you might be surprised at what you'll find. Smart Balance is actually an oil blend rather than a dairy based product. So if you were to use Smart Balance in place of regular unsalted butter in a cake recipe, the result would be quite detrimental.
Let's take a look at the ingredients list for Smart Balance, shall we?
"Natural oil blend (soybean, palm fruit, canola, and olive oils), water, contains less than
2% of whey (from milk), salt, natural and artificial flavor, vegetable monoglycerides
and sorbitan ester of fatty acids (emulsifiers), soy lecithin, vitamin A palmitate, vitamin B6,
vitamin B12, vitamin D, dl-a-tocopheryl acetate (vitamin E), lactic acid, beta carotene
color, and potassium sorbate, and calcium disodium
EDTA (to preserve freshness)"
"Sweet cream, natural flavoring"
Hhhhmm. I won't get on my soapbox just yet about processed "healthier" foods such as Smart Balance (don't worry, that's coming in another post), but you can see there is quite a difference in the makeup of these two products. Thus, Smart Balance is labeled a "buttery spread" and not "butter" because it's nothing like butter.
So resist that urge to casually go about substituting in a recipe unless you know for sure that the general makeup of the two products/foods are very similar. I'll do another post later regarding my thoughts on seemingly healthier food substitutes....so stay tuned!