The fat in an oil and vinegar-type dressing does three things: It creates a pleasant “mouth feel” to the dressing, it provides a “stickiness” to coat the greens, and it dilutes the vinegar so that the dressing is more palatable. But oils carry nearly 2000 calories per cup. Way too much. So we started looking for a substitute.
We started by reviewing other low fat dressings. Many simply diluted the vinegar with water. That was unacceptable. It made for soggy greens, not greens with a pleasant coating of oil and flavor. Some just eliminated the oil. That made the flavors way too strong and without stickiness, simply collected in the salad bowl. Others added a third substance to the mix, usually honey or fruit juice. But that didn’t function as well as oil and added flavors that were not always wanted.
We needed a very neutral-flavored substitute, something that was thick enough to stick to the greens, and something that would mimic the mouth feel of oil. Only a starch seemed to meet those requirements: a starch slurry would provide body, stickiness, and yet have little flavor. We settled on cornstarch. Cornstarch would meet these requirements plus create a translucent liquid that would not materially alter the appearance of the dressing.
We wanted a slurry with a viscosity similar to oil, maybe just a little thicker, when chilled. So we began testing. We ran trials from one teaspoon to 4 1/2 teaspoons per two cups of water. We simply cooked the slurry on the stovetop and then chilled it in the refrigerator.
A slurry made with two teaspoons cornstarch to two cups of water seemed to have the right viscosity, a thin viscosity similar to oil. When we mixed it into a dressing it looked good and made a very satisfactory dressing very similar to that made full-strength with oil.
We tried several different ratios of slurry to oil—from substituting all of the oil for the cornstarch slurry to a 50% ratio. We found that it was always nice to have a little oil in the dressing but that it was not necessary. Our choice was one-fourth oil and three-fourths slurry.
Finally, we decided that a cornstarch based dressing coated the leaves a little better and provided a little more body if the slurry was a little thicker than oil. We settled on three teaspoons for two cups of water.
A starch slurry does not have the same mouth feel as vegetable oil but most of our testers had trouble telling the difference when tasting a small amount in a spoon.
It is an acceptable substitute for those who wish to reduce calories. The reduction of calories is very significant eliminating up to 75% of the calories in a dressing. We ran the nutritional calculations for one of dressing recipes. It reduced the calories from 130 calories per two tablespoon serving to 40.
The cornstarch slurry is slightly milky and the appearance is not as attractive as with a traditional oil and vinegar dressing. It is not significant enough to change the appearance on the salad.
In dressings carrying significant other flavors, such as our French dressing and avocado dressing, you will not be able to tell the difference.
- We recommend substituting a cornstarch slurry for some of the oil in most oil and vinegar dressings. We do not recommend the substitution for dressings calling for olive, walnut, or flavored oils. The cornstarch slurry is most appropriate in dressings with other ingredients added such as ketchup or purees.
- We recommend three teaspoons per two cups of water. Simply mix a little of the water with the cornstarch in a saucepan to dissolve the powder, stir in the rest of the water, and cook until clear and bubbly. Add it to the dressing once it cools.
- We recommend mixing the cornstarch slurry in a batch, two to four cups at a time, and storing it in the refrigerator to use as you make dressings.
- We recommend substituting three-fourths of the oil for the cornstarch mixture but you may successfully substitute more or less.