Only new bottles should be used and these should be thoroughly rinsed
before using and preferably with hot water. Since new bottles have no
tightly adherent particles on the inside, the use of clear water is
sufficient, dependence being placed upon the after process to insure
sterilization.
The bottling should be done at as high temperature as is practicable,
about 165 to 170 degrees F. If the temperature is higher than this, the
possibility of burns in handling is increased, and too much space is
left in the neck of the bottle after corking, due to shrinkage of the
ketchup on cooling, and if much lower, the expansion in processing
causes excessive loosening of caps or corks and breakage. Furthermore,
when low temperature is used, it requires a very long time to heat the
contents of a bottle in pasteurizing. A ketchup is a very poor conductor
of heat and the heavier the body, the longer the time that is required.
The closure may be made with either corks or seals, the recent
improvements in the latter making them much safer than they were a few
years ago.