The judging of ice-cream is the comparing of one product with another or of the one in question with the ideal. In order to make this comparison more simple, a score-card has been devised. This gives a numerical value to each of the characteristics of the material to be judged and makes comparisons easy. The judge should be familiar with the various qualities and defects of the material under his inspection.
—Several score-cards[34] have been suggested for ice-cream, but no one is in universal use as is the case with both butter and cheese.
[34] Baer, A. C., “Ice-cream-making,” Wis. Exp. Sta., Bul. 262, 1916; Mortensen, M., “Classification of ice-creams and related frozen products,” Ia. Exp. Sta., Bul. 123, 1911; Washburn, R. M., “Principles and practice of ice-cream-making,” Vt. Exp. Sta., Bul. 155, 1910; Frandsen, J. H., and Markham, E. A., “The manufacture of ice-cream and ices,” Orange Judd Company, 1915.
In the New York State College of Agriculture at Cornell University, two score-cards are used. They are as follows:
| Score-card No. 1 | Score-card No. 2 | |||
|---|---|---|---|---|
| Flavor | 45 | Flavor | 40 | |
| Body and texture | 35 | Body and texture | 25 | |
| Richness | 10 | Bacterial count | 15 | |
| Appearance | 5 | Richness | 10 | |
| Package | 5 | Appearance | 5 | |
| Package | 5 | |||
| Total | 100 | Total | 100 | |
These score-cards consider the same characteristics except that No. 2 includes the bacterial count. Naturally the inclusion of another characteristic changes the numerical value of the others. Score-card No. 1 is for use only when there is not time to make a bacterial count, such as for laboratory work. When an exact comparison is desired, the bacterial count should be made. If undesirable or large numbers of organisms are present, they affect usually the flavor and body and texture, although this is not always true. For this reason, the numerical value given to bacterial count has been taken from flavor and body and texture.
—If the ice-cream is to receive a perfect score, the characteristics should be as defined. If not, the ice-cream is defective and the score should be cut.
Flavor.—The ice-cream should have a pronounced flavor which will blend with that of the cream to give a clean, desirable typical flavor.
Body and texture.—The body should be firm and mellow. It should not be tough or rubbery, neither soft or mushy. The texture should be smooth and velvety and entirely free from graininess and lumpiness.
Richness.—If the ice-cream meets the legal requirements, it should be given a perfect score. If it falls below, it should be scored zero.
Appearance.—The ice-cream should have an attractive appearance and be of the characteristic uniform color.
Package.—The package should be neat and clean and, if for long shipment, some provision should be made to protect the ice on top of the packing-tub.
Bacterial count.—An ice-cream which has a count of 20,000 should be considered perfect. For each increase of 20,000 above this, one point should be deducted from the score.
If a number of samples is to be scored, it is the usual custom to examine several to gain an idea of how the quality runs. This is called establishing a key or standard. When this has been done, all the samples can be scored and the best will not be rated too high nor the poorest too low.
—It is almost impossible to make an ice-cream which does not have some defect. These can be discussed best under the characteristics as given in the score-card.
of ice-cream are largely due to objectionable flavors in the materials employed, or to the use of too much or too little of certain ingredients.
Some of the common causes are:
1. Use of cream of bad flavor.
2. Use of cheap flavoring extracts.
3. Use of too little or too much sugar.
4. Use of materials which do not give the characteristic flavor.
5. Disagreeable flavor due to use of poor fruits.
6. Lack of flavor due to use of too small an amount of flavoring materials.
7. Too pronounced a flavor or not pronounced enough.
8. Condensed milk flavor.
9. Salty ice-cream.
10. Gelatine or gum tragacanth flavor.
Of the ten causes mentioned all but number one are within the control of the ice-cream manufacturer. However, the flavor of the cream is a very vital question and the one usually causing the greatest difficulty.
—The texture refers to the molecular structure. As the ice-cream is an emulsion of materials of varying specific gravities, it is difficult always to get these different ingredients to mix in the same manner. The greatest defect in the texture of the ice-cream is graininess. This may be caused by the incorporation of too much air or the separation of the water crystals. After the ice-cream has been transferred from the freezer to the pack-cans, the latter should be placed at once in cold surroundings; if not, the cream around the outside and bottom of the can will melt and on being hardened will be grainy, due to the melting and separation of the water crystals. Graininess may be due to a lack of binder or sometimes to the crystallization of the sugar in the condensed milk.
The body of the ice-cream refers to the structure as a whole. The common defects in body are hard, brittle, soft or watery. In order to obtain an ideal body, the ice-cream must contain a certain amount of milk-fat and other solids; also this cream must be frozen properly. If the ice-cream lacks solids, the body is very likely to be soft or watery. The age of the cream, whether or not it has been pasteurized, and method of freezing, have a decided effect on the body.
Sometimes in freezing the fat becomes churned; this results in chunks of fat in the ice-cream. It is caused by the freezer running too fast or by putting the cream into the freezer too warm.
The following summary of two bulletins gives the effect of solids on the smoothness and keeping qualities of ice-cream and the effect of binders on the melting and hardness. These directly affect the body and texture.
Effect of solids on smoothness and keeping quality of ice-cream:[35]
[35] Brainard, W. K., “Smoothness and keeping qualities in ice-cream as affected by solids,” Va. Exp. Sta., Tech. Bul. 7, 1915.
“1. Smoothness and keeping quality or stability of texture of ice-cream are closely associated.
“2. Smoothness depends upon the amount and fineness of division of solids present other than those in true solution, within limits, that is, the smoothness depends upon the size and distribution of ice crystals which in turn depend upon the number and nearness together of minute solid particles which interfere with crystallization and reduce the size of the ice crystal.
“3. Colloidal solutions of solids other than fat are best adapted to ice-cream-making. The finer the division the better.
“4. The finer the emulsion of the fats the better the homogenizer has its application in this respect.
“5. The keeping qualities of ice cream depend upon the stability of the mix. That is, the keeping qualities of ice cream made from a given mixture will depend upon the disposition of the solids in that mixture to separate from the liquid, which in turn depends upon the fineness of division of the solids. The finer the division, the better the keeping qualities up to the point at which the solid merges into a true solution.”
Effect of binders on the melting and hardness of ice-cream:[36]
[36] Holdaway, C. W., and R. R. Reynolds, “Effect of binders upon the melting and hardness of ice-cream,” Va. Exp. Sta., Bul. 211, 1916.
“Plain ice-cream.—In plain ice-cream (control) as the per cent of fat increases the cream becomes softer. A medium amount of butter fat, combined with other material than milk solids, produces a stiff cream. When too much fat is present whipping takes place, producing a cream that is soft and fluffy in appearance. Ice-cream made from eight per cent cream is no harder than from nineteen per cent cream, while thirty per cent plain cream is much softer than eight per cent or nineteen per cent cream. In plain ice-cream the presence of fat increases the power to resist melting. This resistance is most noticeable between the melting of the eight per cent and nineteen per cent cream. Thirty per cent cream shows the power to resist melting to a less degree.
“Cream containing gelatine.—Gelatine in a large or small quantity produces similar effects, depending upon the richness of the cream used. The power to withstand pressure and the melting resistance increases as the amount of gelatine increases, when compared with the control ice-cream with a similar fat content. The hardest and most heat resisting ice-cream is produced with a medium per cent of fat and a large amount of gelatine. With gelatine, the presence of fat seems to be essential to produce hardness and melting resistance until a point is reached where whipping affects the texture. After whipping begins the incorporated air reduces the hardness and melting resistance. Ice-cream containing one ounce of gelatine per gallon has more the appearance of pudding than ice-cream. Four ounces of gelatine gives about the same hardness as four ounces of cornstarch, but it is much better, producing a smoother cream which is more stable under ordinary conditions.
“Cream containing gum tragacanth.—Gum tragacanth with a low per cent of fat produces an ice-cream that is slightly harder, with slightly more power to resist heat than plain ice-cream. As the per cent of fat is increased with this filler, the power to resist pressure and heat decreases, falling below plain cream, showing that gum tragacanth acts as a filler and not as a binder. Its most noticeable effects are on the texture of the ice-cream, because of the nature of the gum, is to impart a smoothness which becomes sliminess when large quantities are used.
“Cream containing cornstarch.—When cornstarch is used as a filler a slight increase in hardness and melting resistance is noticeable with nineteen per cent when compared with eight per cent ice-cream. Also it produces an ice-cream that has more resistance to heat than plain ice-cream of the same per cent fat. When used as a filler it compares favorably with a similar amount of gelatine but the starch ice-cream is more granular than the gelatine, while gum tragacanth produces a smooth soft cream.”
—The only defect in richness is a lack of fat and solids not fat. The ice-cream should meet the legal standards; if not it is defective.
—Many times the ice-cream does not have an attractive appearance. It may be rough, grainy and coarse, or partly melted. Often it will melt on the outside and run while the inside will be very hard. The ideal ice-cream is one which will have the same degree of softness throughout. The color is not always characteristic as the fruit may not be distributed uniformly.
—Anything which detracts from the neatness of the package is a defect. Badly dented or rusted cans are not attractive. The tubs may not be clean or neatly painted or lettered. The parchment paper circles being omitted from the top of the can constitutes a defect.