About Gammelost From: Cheese Varieties and Descriptions - U.S. Department of Agriculture, AGR. Handbook No. 54 - by George P. Sanders, 1953

Gammelost, made from sour skim milk in Norway (principally in the counties of Hardanger and Sogn), is a semisoft, blue-mold, ripened table cheese, with a rather sharp, aromatic flavor. The principal ripening molds are species of Mucor, Rhizopus, and Pencillium. The rind is brownish and the interior is brownish-yellow with a blue-green tint; the color darkens with age. The cheese is round and flat, usually about 6 inches in diameter, and from 5 to 6 inches thick. It weighs usually between 6 and 9 pounds, although some cheeses may weigh more than 25 pounds. The cheese is made by one method in Hardanger and by a slightly different method in Sogn.

In the Hardanger method, about 0.5 percent of lactic starter is added to skim milk and, after souring for a day or two at 66 degrees F., it is put into a vat and warmed slowly to 145 degrees. After about 30 minutes at that temperature, the curd is dipped into cloth bags and pressed heavily. After pressing, the curd is removed from the bags, broken up, and packed in cloth-lined forms which then are covered and placed in boiling whey for 3 1/2 hours. This practically sterilizes the cheese and changes its texture. The next day the cheese is removed from the forms and put in a warm place for a day or two to dry, after which it is pierced with metal needles that have been inoculated with a mold-Penicillium roqueforti, or a related species-that develops a greenish-blue mold throughout the cheese. It is then placed on shelves in a curing room which is maintained at a temperature of 50 to 55 degrees and a relative humidity of 90 percent. A Mucor, which is propagatd by handrubbing the surface with mycelium from older cheeses, develops on the surface of the cheese. The cheese in inverted daily or at least every other day, and rubbed or cleaned if necessary. The curing period is about 4 weeks or somewhat longer.

In the Sogn method, 1 1/2 to 2 percent of starter is added to the skim milk, and it is soured at a temperature of 72 to 75 degrees F.; on the second day, the milk may be transferred to the cheese vat where souring is completed at a temperature of 77 degrees. When the milk has reached the desired stage of souring (a later stage than in the Hardanger method), it is heated slowly to the boiling point. The whey is removed, and the curd is heated to about 195 degrees, then placed in forms to drain. The forms are covered with cloths and kept in a warm place. After the whey has drained off, the curd is removed from the forms, crumbled fine, inoculated with mold, and repressed. The next day the cheeses are removed from the forms, dried in a warm place for 4 or 5 days, and then taken to the curing room. The curing process is the same as in the Hardanger method.

In both methods, after the cheese is partly cured, it may be put in chests lined with straw that has been treated with heated juniper extract. The yield of cured cheese is between 4 and 5 1/2 pounds per 100 pounds of skim milk

Analysis: Moisture, not more than 52 percent (usually 46 to 52 percent); fat, 0.5 to 1.0 percent; protein, 45 to 50 prcent; ash, 2.5 percent; and salt (in the ash), 1 percent.

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