168 



THE COMMERCIAL CANNING INDUSTRY 



more readily result. All mushroom growers will 

 find the drying process of value in order to make 

 use of portions of the stems and of mushrooms 

 rather too far advanced for the demands of the 

 best markets. They may then, moreover, be reduced 

 to powder, by passing through an ordinary grinder, 

 and this powder is in considerable demand for sauces 

 and as seasoning. 



The canning of mushrooms in liquid, according to 

 many methods which have been published, involves 



Fig. 247. 



Boletut telleus, the bitter boletus of doubtful 

 reputation. 



blanching by means of a solution containing alum 

 and bisulphite of soda. An effective home method, 

 preserving the flavor fairly well, is this : Peel and 

 throw into boiling water, containing for each 

 gallon three ounces of salt and the juice of two 

 lemons. After five minutes, put into clean pint-jars 

 and cover with a brine containing per gallon 

 from one to two ounces of salt and a little lemon- 

 juice. They are then brought gradually to the 

 boiling-point and boiled for about fifteen minutes. 

 Preserving in butter, an expensive but common 

 process, is somewhat as follows: Clean and peel as 

 usual and place for a few minutes in cold water, 

 acidulated with vinegar or lemon-juice. Dry with 

 a clean cloth, and use for each quart of mushrooms 

 three ounces of butter, a small teaspoonful of salt, 

 a little pepper and the juice of one lemon. Melt 

 the butter in a stewpan, add the mushrooms and 

 the seasonings; cook slowly, until nearly dry, shak- 

 ing to prevent sticking. Then put into jars and 

 fill with melted butter. Heat in boiling water for 

 ten minutes, close the top, cool gradually and 

 seal. 



Mushroom ketchup is commonly made as follows: 

 Clean, cut into slices and dispose in layers one- 

 half inch thick in an earthen dish, sprinkle with 

 salt, and repeat until the dish is full. Place in the 

 refrigerator or a cool place for at least two days. 

 Then crush and strain the product through a cloth. 

 Boil the liquid in a porcelain-lined kettle, adding 

 for each quart one-fourth ounce allspice, one-half 

 ounce ginger root, one dozen cloves and several 

 blades of mace. Boil fifteen minutes, strain through 

 flannel into sterile bottles, cork and dip into sealing 

 wax. Or, in the spring, omit the ginger, and add 

 instead, at the time of maceration in refrigerator, 

 to each two pounds of fresh mushrooms about three 

 ounces of fresh walnut husks, finely chopped. 

 Again, gelatine may be added prior to the last 

 boiling, and the product may be used as a jelly, 

 when it is not desired to keep it for a long period 

 of time and to avoid bottling. 



Pickled mushrooms may be readily prepared, but 

 they are not greatly esteemed. 



THE COMMERCIAL CANNING INDUSTRY 

 By Samuel C. Preseott 



Canning is so called because the food material, 

 either animal or vegetable, is "packed" in metal 

 or glass containers, hermetically sealed and steril- 

 ized or "cooked" by the application of heat. The 

 containers, commonly spoken of as "cans," are 

 generally made of tin plate, although, for certain 

 kind of foods, glass jars are sometimes used. The 

 process is capable of very wide application, as all 

 kinds of foods, except those eaten only in the raw 

 condition, may be preserved in this way, and thus 

 the abundance of one season or one locality may 

 be made available at another place or time. 



The general object of the process is apparent 

 from the foregoing, but it may be stated that the 

 main problem is to prevent decomposition or spoiU 

 ing, changes induced in foods by the activity of 

 various kinds of microorganisms which ferment 

 or putrefy the foods, giving rise to products of 

 harmful or undesirable character and rendering the 

 food unfit for use. 



From a sanitary point of view, canned foods, if 

 properly prepared, are of the highest value, as they 

 are free from bacteria. This fact, combined with 

 their convenience and the ease with which they 

 may be transported, has led to an enormous manu- 

 facture and consumption of these very satisfactory 

 food products. In this article the canning of vege- 

 table foods only will be considered. 



Methods of sterilization. 



Sterilization of the can and its contents is 

 effected by one of the following methods : (1) water 

 bath, (2) chemical bath, (3) steam under pressure in 

 strong chests or kettles frequently called "retorts." 

 Pigs. 248 and 249 show sterilizing or cooking 

 apparatus. 



(1) The water bath. As its name implies, steri- 

 lization by this means consists in boiling the cans 

 or jars for a single period or discontinuously, a 



