c. With fat added--the cream cheeses of

the Neufchâtel group (both American and European)--such as Cream, Gervais, Malakoffs, etc. 108

Section II. Cheeses ripened.

Subsection A. Soft cheeses (40 to 50% water).

1. Curdled by souring, heated, then ripened.

Hand cheese, Pennsylvania pot cheese, Harz, etc. 112

2. Curdling by souring and rennet, ripened

Ripened (French) Neufchâtel 114

3. Curdled primarily by rennet.

a. Ripened by mold--Camembert, Brie and their allies 117

b. Ripened by bacteria.

* Made from soft or friable curd--d'Isigny, Liederkranz, etc. 134

** Made from firm or tough curds--Limburger and allies 139

Subsection B. Semi-hard cheeses, firm, well-drained (38 to 45% water)

a. Curd not cooked, ripened by molds. * Made from friable curd--Roquefort 150

** Made from firm or tough curd--Gorgonzola, Stilton and such French forms as Gex, Septmoncel 158

b. Curd cooked and ripened by bacteria,--brick, Munster, Port du Salut (Oka) 164

Subsection C. Hard cheeses, cooked and pressed (30 to 40% water).

a. Ripened without gas holes. 1. Dutch--Edam, Gouda 173 2. Danish. 3. The Cheddar group. * English--Cheddar and numerous related forms known principally in Great Britain 184 ** American--the factory Cheddar of United States and Canada 184

b. Ripened with the development of gas holes. * Holes large--Swiss-Emmenthal, Gruyère, American Swiss 276

** Holes small--Parmesan and related varieties 288

Such a classification brings together series of products in which there is essential similarity in the final output, however great the differences in manipulation. It does not consider all varieties and specialties. Some of these groups are important enough to demand special mention.

+105. Processed cheeses.+--Cheese of any group may be run through mixing and molding machines and repackaged in very different form from that characteristic of the variety. In such treatment, the texture and appearance may be so changed as to give the effect of a new product. Substances (such as pimiento) are added to change the flavor. Or the product may be canned and sterilized with equally great change of flavor and texture. One thus finds Club made from Cheddar; Pimiento from Cream, Neufchâtel or Cheddar; similarly olive, nut and other combinations are made. The possible variations are numerous.

+106. Whey cheeses.+--Several products bearing cheese names are made from whey. These take the forms of the recovery of the albumin and casein separately or in a single product, and the recovery of the milk-sugar either alone or with the albumin. Whey cheeses have been especially developed by the Scandinavian people, although some of them have their origin in the south of Europe. Certain of these varieties are produced on a limited scale in America.

There are a number of forms fairly widely known that are difficult to place in this scheme of groups. Among these are Caciocavallo, Sap Sago.

+107. Soft and hard cheeses.+--Another commonly used classification makes two groups: (1) soft cheeses; (2) hard cheeses. In such a classification the semi-hard group presented here is included with the soft cheeses. Some cheeses of this group are soft in texture. This is correlated with high water-content, high fat-content or both together.

+108. Relation of moisture to classes.+--In this classification the water-content reflected in the texture of the cheese assumes first place. To carry the analysis somewhat further by showing the correlation between water-content and certain factors, a tabulation of well-known varieties of typical groups is presented (Table III). In this table the series of typical dairy products are first arranged according to water-content of the final product. Approximate limits of percentages of milk-fat are also given, because milk-fat frequently affects texture to a degree almost equal to water. Column 4 gives the period within which the more quickly perishable cheeses are usable, and the length of the ripening for the more solid forms. The correlation between water-content, texture and the time of keeping is clearly shown for most varieties.

TABLE III

CORRELATION WATER- AND FAT-CONTENT WITH RIPENING

------------------+--------+--------+-------------+-------------- | PER | PER | | VARITY OF | CENT | CENT | PERIOD | RIPENING | WATER | FAT | REQUIRED | AGENT ------------------+--------+--------+-------------+-------------- Cheese: Soft, | | | | Cottage | 70 | trace | a few days | Bacteria Skim Neufchâtel | 70 | trace | a few days | Bacteria Neufchâtel | 50-60 | 12-28 | a few days | Bacteria Camembert | 50 | 22-30 | 3-5 weeks | Molds Cream cheese | 40-50 | 35-45 | a few days | Primarily | | | | bacteria | | | | Semi-hard: | | | | Limburger | 40-45 | 24-30 | 3-6 months | Bacteria Roquefort | 38-40 | 31-34 | 3-6 months | Mold Brick | 37-42 | 31-35 | 3-6 months | Bacteria | | | | Hard: | | | | Cheddar | 30-39 | 32-36 | 6-12 months | Bacteria Swiss | 31-34 | 28-31 | 9-18 months | Bacteria | | | | and yeasts Parmesan | 30-33 | | 2-3 years | Bacteria ------------------+--------+--------+-------------+--------------

The soft cheeses are quickly perishable products. Bacteria and molds find favorable conditions for growth in products with 45 to 75 per cent of water. If such growth is permitted, enzymic activities follow quickly with resultant changes in appearance, texture, odor and taste. Refrigeration is necessary to transport such cheeses to the consumer, if properly ripened. Trade in these forms may continue throughout the year in cool climates and in places where adequate refrigeration is available. Practically, however, outside the large cities this trade in America is at present limited to the cold months; inside the large cities much reduced quantities of these cheeses continue to be handled through the year.

In the stricter sense, the soft group of cheeses falls naturally into two series: (1) the varieties eaten fresh; and (2) the ripened soft cheeses. Those eaten fresh have a making process which commonly involves the development of a lactic acid flavor by souring, but no ripening is contemplated after the product leaves the maker's hands. In the ripened series, after the making process is completed, the essential flavors and textures are developed by the activity of micro-organisms during ripening periods varying in length but fairly well-defined for each variety.

In contrast to the soft cheeses, the hard kinds are low in water-content, ripen more slowly and may be kept through much longer periods. They retain their form through a wider range of climatic conditions. They develop flavor slowly and correspondingly deteriorate much more slowly. Such cheeses are in marketable condition over longer periods. In their manufacture the cooking of the curd takes a prominent place.

+109. Relation of heat to classes.+--The close relation between the heat applied and the product sought forms the basis of a striking series of graphs (Fig. 12, page 78). These show the changes hour by hour in the heat relation during the making process of a series of widely known forms, each of which is chosen as typical. In some of these forms, heat is applied but once to bring the milk to the renneting temperature typical for the variety. Subsequent manipulations are accompanied by a steady fall in temperature. In other forms, the curd when solid is specially heated or "cooked" to bring about the changes characteristic of the variety. These contrasts are clearly brought out by the graphs which represent practices well recognized for the varieties. The detailed process for these groups is considered in succeeding chapters.