Since the Fourth of July, we’ve been on an ice cream making tear, a fact which probably hasn’t escaped the notice of regular readers of this blog. I’ve heard from some of you who have tried your hand at making low-carb ice cream from the blog recipe and most of you reported that the taste and texture of these low carb creams are pretty darned good. And I agree. Their one deficiency is in what’s called ‘mouth feel.’
Mouth feel, a sort of ineffible quality of a food, has to do with how it sits in your mouth and how it dissolves and changes. For instance, does it break apart smoothly? Does it seem gritty? Is it gone too fast or does it linger just long enough? Does it leave an oily sensation or a clean one on the tongue when it’s gone?
It’s in the mouthfeel department that low-carb homemade ice creams, delicious though they are, slightly miss perfection. And the problem stems chiefly from their lack of sugar, which in a traditional ice cream recipe serves functions beyond sweetening the product, an important one of which is to modify the behavior of the fat content.
Something happens to fat when it’s blended with sugar; it loses its oily mouth feel. To easily illustrate this effect, think of what it would feel like to chomp down on big spoon of pure butter, to wallow it around in you mouth, and swallow it. What do you get? An oily mouthfeel.
Now, cream that butter with powdered sugar and what do you get? Frosting…and, like magic, no oily mouthfeel. The same thing happens when you chill and churn cream (or half and half or coconut milk) sweetened with sugar to make that frozen concoction that helps us hang on (apologies to Jimmy Buffet.)
But in a low carb version that uses Splenda or Stevia or some other artificial (non-sugar) sweetener, there’s no magic transformation and the mouth-waterin’ mouthful leaves a decidedly oilier residue lingering on the tongue than we might ideally desire. Not quite like the straight butter example, but not the rich, but clean finish it would have had were sugar in the mix.
That slight imperfection led us to do a little sleuthing, reading, and experimenting, which led us to a handbook on sweetener alternatives and the properties they impart, which led us to try adding some polydextrose powder to the mixture. Afterall, it’s what the big boys use, so why not us home folk?
Polydextrose is a long chain of dextrose molecules (call me mistress of the obvious) and dextrose is nothing more than double glucose–ie, two glucose molecules hooked together. Glucose, of course, is blood sugar. That’s why dextrose is the sugar used in IV solutions. It’s the ‘D” that’s being called for when the doctor shouts out orders to hang a liter of D5W (5% dextrose water) or D5Normal (5% dextrose in salt water) or to push some D50 (50% dextrose solution) on ER or Gray’s Anatomy.
While the human GI tract can easily snap apart a single molecule of dextrose to harvest and absorb the two glucoses, once polymerized into the long polydextrose chains, the tin snips of the digestive process can no longer break the links and so polydextrose behaves as a fiber. Like most soluble fibers it passes intact and unabsorbed through the small intestine, then on down stream to the waiting friendly bacteria (in the colon, mainly) who do have the tools to break it apart and use it or ferment it.
Even though once in the body it doesn’t behave like sugar in raising insulin or blood glucose levels, polydextrose still retains many of sugar’s food tech properties, imparting a slight sweetness (about 1/10 the sweetness of sugar) and taking sugar’s place in recipes by adding bulk to and improving the mouthfeel of the finished product. Like fiber, however, its indigestible nature can cause a little bit of GI rumbling, bloating, and gas if you overdo it. Commercially available polydextrose powder also contains a bit of citric acid and about 10% sorbitol, which probably also contributes to the mild degree of GI agitation that can occur.
You may be able to find polydextrose at your local natural foods grocery store, but if not, you can find it online in reasonable-sized quantities. For a source, click here.
By educated guessing and some trial and error, I arrived at an amount of polydextrose to add to a batch of ice cream that would achieve the desired mouthfeel without causing much in the way of GI side effects.
And the answer is: 1/3 to 1/2 cup per 1 quart batch.
By quart batch, I refer to the Coconut Milk Ice Cream recipe in the previous blog. Obviously, to make the low carb version, opt for the Splenda instead of the dextrose powder and use your choice of cream and/or half and half for the dairy version or the coconut milk plus rice milk for the non-dairy version. Then, modify the instructions there as follows: add about 1/3 cup polydextrose to the 6 beaten egg yolks (as you would normally have added sugar in a traditional recipe) and continue to beat until thick and pale. Then temper them with the sweetened hot cream (or coconut milk) and proceed with the recipe just as written. If you still perceive a slightly oily mouthfeel, next time up the amount of polydextrose to 1/2 cup. (You’re walking a fine line here between good mouthfeel and too much of the fiber effect, so see what works best for you.)
Last night, the time came to test the hypothesis. Since we’d had my fresh fruit flavor choice (peach) the other day,it was Mike’s turn to choose. For him, the go-to fruit choice for almost anything from savory compotes to cobblers to pastries and most particularly for ice cream is cherry. So bowing to spousal pressures, I cranked up a batch of Cherry Vanilla.
We’d bought a bag of fresh dark sweet cherries at the farmers’ market, which I thanklessly halved and pitted, turning my fingernails maroon in the process. After a course chop, I added about 1 cup of the cherries to the cooled ice cream base, then chilled the whole lot properly before churning. It was, indeed, yummy with just the right mouthfeel when it came freshly churned from the machine.
Ben and Jerry got nothin on me! I think I’ll call it Poly Woly Cherry.