How about a heaping bowl of guar gum and pulverized spent vanilla pods? Can ice cream makers fool Mother Nature (and our tasters)?
When it comes to counting on the magic of food engineering to improve on Mother Nature, ice cream manufacturers really take the cake. Sure, some supermarket vanilla ice creams attempt to get by on just the basics--"all natural" blends of cream, sugar, vanilla, and little else. But many cartons sport labels that read like highlights from a chemistry textbook. Some manufacturers substitute imitation vanilla extract for the real stuff, while others bet on visual appeal, using ground-up vanilla-bean specks to give the illusion of full flavor.
Does any of this hocus-pocus deliver a better product? To find out, twenty Cook's Illustrated staff members tasted 18 supermarket vanilla ice creams--10 French-style brands (made with egg yolks) and eight regular (made without egg yolks).
Creamy Secrets
As varied as the ice creams looked on paper, the side-by-side comparison was striking. Some were fluffy and light; others were dense and rich. A few had assertive vanilla notes that reminded tasters of "frozen, boozy eggnog." Several ice creams, on the other hand, seemed to be lacking in vanilla flavor altogether.
Contrary to expectations, the French vanilla ice creams--prized for the rich flavor and creamy texture that comes from egg yolks--did not sweep the competition. Many without eggs were praised for their custardy texture and eggy mouthfeel. There was something in the eggless ice creams that was giving them a faux-French demeanor. After studying the labels we soon noticed a clear pattern. Every regular-style ice cream that had passed for French vanilla contained substances such as carob bean gum, carrageenan, guar gum, and mono- and diglycerides. Could these additives be mimicking the textural effect of egg yolks?
Carob bean gum, carrageenan, and guar gum are all stabilizers, added to ice cream to help keep ice crystals from forming and wreaking havoc on texture. Mono- and diglycerides, on the other hand, are emulsifiers, added to ice cream to keep the fat from separating--which, in turn, contributes a luscious, silky texture. Egg yolks, which naturally contain the emulsifier lecithin, serve this same function in French-style ice creams. So it was the mono- and diglycerides that had fooled our panelists into praising the "custardy" texture of the eggless ice creams.
A much clearer picture was emerging: High fat content and egg yolks can give ice cream a rich, creamy texture, but the judicious use of stabilizers and emulsifiers goes a long way toward making up for the absence of either one. The ice creams in our lineup that got the lowest scores for texture have low fat content and no egg yolks, stabilizers, or emulsifiers (that is, the "natural" regular-style ice creams).
Looks Can Be Deceiving
Of course, ice cream is more than just creamy. Some of the best-textured contenders fumbled when it came to flavor. Weak vanilla flavor was the reason cited most often by panelists for awarding an ice cream a low score.
There are three forms of vanilla found in supermarket vanilla ice creams. Natural vanilla extract is made by steeping ground vanilla beans in a solution of alcohol and water to extract more than 240 flavorful compounds, the most dominant of which is called vanillin. Imitation vanilla extract is made by synthesizing vanillin from either eugenol (found in clove oil) or lignin (a by-product of the paper industry). The third form is vanilla beans themselves.
Only two of the ice creams contained imitation vanilla extract, and both scored poorly. Clearly, natural vanilla is a key component in good ice cream. But how much is enough?
To answer this question, we had our lab examine all 18 samples for vanillin content and found that more vanillin generally translated to higher ratings from our tasters, but there was a limit. Ice creams with more than 10 milligrams tended to lose points for "extract overkill," while those with fewer than 4 milligrams had tasters asking "where's the flavor?" Even more striking were the differences in vanilla-bean specks found in about half of our samples: In some, the specks looked like a uniform sprinkling of finely ground black pepper; in others, the pieces were large and less frequent. But seeing vanilla specks doesn't necessarily mean that you're going to taste vanilla.
To test the effectiveness of seeing vanilla specks, we ran taste tests with and without blindfolds. When asked to pick the samples with the most vanilla flavor, tasters almost unanimously chose the samples with bean specks. But when we ran the same test with blindfolds, tasters chose samples without bean specks as having the most intense vanilla flavor. The lab confirmed these results. Research confirmed that these "vanilla bean specks" are the pulverized pods of spent vanilla beans--not the flavorful beans themselves--and carry little to no flavor.
The Cream of the Crop
So where did we come out? When it comes to vanilla ice cream, some strategic engineering is actually a desirable thing. Our tasters liked both French-style ice creams with stabilizers and regular (yolkless) ice creams with stabilizers and emulsifiers. Our two top winners included a sample of each type.
Fluffiness and Overrun
All ice creams are aerated to make their texture lighter and softer. Federal regulations allow manufacturers to increase the volume of ice cream by up to 100 percent. The air added to the ice cream is called overrun. Premium brands with a dense texture (often sold in pint containers) have less overrun that fluffy brands (often sold in big containers).
Brands with low overrun (between 21 percent and 24 percent) took most of the top spots in our tasting (including second, third, and fourth), while brands with high overrun (between 78 percent and 97 percent) landed in the last four spots. But there was one brand that did not fit this neat pattern. Our taste-test winner has 94 percent overrun (the second-highest in our tasting). It achieved better texture through better engineering. So what does this mean in practical terms? A 10-ounce serving of our winner wll tower over a regular sugar cone. A 10-ounce serving of our second-place finisher (with 21 percent overrun) looks pretty skimpy by comparison.
See the Results
