2 BULLETIN 1009, U. S. DEPARTMENT OF AGRICULTURE. 



Because the Net Weight Amendment to the Federal Food and 

 Drugs Act and many State laws require that food in package form 

 bear a statement of the quantity of contents, the obligation of the 

 food official to the consumer includes the promotion of the delivery 

 of bottles of food which vary as little as possible from the stated 

 quantity of contents when the possibilities of good commercial prac- 

 tice are taken into consideration. The obligation of the bottler to 

 the consumer calls for an effort to deliver bottled food products, 

 such as flavoring extracts, mineral waters, carbonated and uncar- 

 bonated beverages, molasses, honey, maple sirup, vinegar, olive oil, 

 essential oils, table oils, catsup, and salad dressing, which are as 

 uniform in quantity of contents as is commercially practicable. The 

 bottle manufacturer, therefore, is under direct obligation to the 

 bottler and indirect obligation to the consumer to furnish bottles 

 which are as uniform in capacity as it is commercially possible to 

 make them. 



It is the purpose of this bulletin to describe a commercial method 

 of bottling which may be considered " good," to calculate maximum 

 variations in the volume of bottled liquids used as foods when packed 

 in accordance with specified good commercial practice, and to present 

 data showing that the calculated maximum variations of the good 

 commercial practice outlined can be met by the bottler. 



The results of the investigation here reported are intended to be 

 applicable to liquid foods only. 



SOME CAUSES OF VARIATION IN VOLUME OF FOOD IN BOTTLES. 



The variation of the quantity of food in the bottle depends on 

 many factors, since various types of bottles are manufactured by 

 various methods and filled by various methods. The causes of the 

 variations are cumulative, extending far back into the history of the 

 bottle. In order to direct attention to the relative weight of some of 

 the causes, certain pertinent factors in bottle manufacturing, 

 methods of bottling, and types of bottles used as food containers 

 are mentioned 



BOTTLE MANUFACTURE. 



Bottles are manufactured by three processes: Hand, semiauto- 

 matic machine, and automatic machine. The processes vary in two 

 particulars — first, the method of gathering the proper amount of 

 glass to be blown into a bottle, and, second, the method of blowing 

 the bottle. 



Hand blowing is the oldest and simplest method of manufacture. 

 In this process one end of the punty, a hollow tube about 6 feet 

 long, is inserted in the molten glass and rotated until the amount of 

 glass necessary to produce a bottle of the desired weight has been 



