soft drinks | Page 8

was rst manufactured in Belfast in the 1870s.
By the second half of the century, carbonate manufacturers could buy a very
comprehensive range of avours to use in their products and the science of avour
chemistry was well under way, as demonstrated by the development of articial
vanillin by Tiemann and Wallach in 1872. This reduced the cost of vanilla avour
by a factor of more than×30 (from $300/lb ($555/kg) to less than $10/lb ($19/kg)).
As mentioned above, many of the popular drinks of today were on sale before 1900.
The quantity of CO
2added to a drink has a pronounced effect upon its character and
avour impact. The solubility of CO
2in water decreases as temperature increases
but increases with increasing pressure, that is, a given level of carbonation will
generate a higher pressure as the temperature increases. Ice cold water (0
◦C) will
dissolve 1.7 volumes (3.4 g/l) of CO
2at atmospheric pressure. At CO2levels
and at temperatures above this, increased pressure must be applied to retain the
CO
2in solution. In some of his early highly carbonated waters Nicholas Paul used
carbonations of up to eight volumes of CO
2(16 g/l); however, the usual carbonation
levels now range from about two volumes for a slightly sparkling fruit drink to
around ve volumes for a mixer drink such as tonic water (see Table 1.2). Mixers
require higher levels of carbonation because they are intended to be diluted with
spirit before consumption.
In the early 1800s, colours were restricted to mainly variants of brown and red,
that is, those which could be produced from caramel or cochineal. This remained
the case until the introduction of synthetic aniline dyes around 1880. TheMineral
Water Maker’s Manual for 1885described the manufacture of some colours from
vegetable extracts but stated that there was a trend for these to be replaced by
the new aniline-based dyes, even though these ‘are considered objectionable by
many’. It also strongly warned manufacturers not to use colours such as arsenic
sulphate, lead chromate, mercury sulphate and copper arsenite, which it claimed
were sometimes used to colour confectionery.
1.3.4 Packaging
Waters from natural springs were recognised as being safe (even healthy) to drink
from earliest times and were transported by whatever means that were available.
Table 1.2Typical carbonation levels.
Volume (g/l)
Lightly sparkling 2.0 4
Fruit juice carbonate 2.5 5
Lemonade 3.0–3.5 6–7
Cola 4.0 8
Mixer 4.5–5.0 9–10

Steen: “chap01” — 2006/4/27 — 18:30 — page9—#9
INTRODUCTION9
Naturally carbonated waters were collected into earthenware containers, which
were tightly sealed with cork and wax, usually not very successfully. The use of
earthenware bottles proved to be unsatisfactory for the more highly carbonated aer-
ated mineral waters and they were soon replaced by glass bottles. Many of the early
glass bottles had round bottoms ensuring that they were stored on their side, thereby
keeping the corks moist and so preventing leakage from corks drying out. The man-
ufacture of glass bottles was a skilled job as they were hand blown. Although some
semi-automation had been introduced earlier, the rst patent for an automatic glass
bottle blowing machine was granted to Michael J. Owens in the USA in 1904.
High pressure generated inside bottles by the carbonation caused frequent leak-
age and, although improved by wiring-in-place, corks were generally unsatisfactory.
Many alternative forms of seals were patented over the years and these fell broadly
into three main categories:
1. Wire and rubber sealing devices were especially popular in the USA until
the early 1900s. The wire could be either an internal spring form, which
held a seal in place on the inside of the neck, or of the external ‘swing’ type,
in which an external wire frame was used to hold a ceramic plug in place
against a rubber seal. First patented by Charles de Quillfeldt in 1874, this
latter type is still currently in use for some speciality beers.
2. Variations on the theme of using an internal ball made from rubber, ebonite
or glass were developed and used with varying degrees of success. The ball
was held in place by the internal pressure. The most successful of these was
patented by Hiram Codd of London. His bottle was widely used in the UK
from the 1870s until the 1930s. A similar bottle, but with a oating rubber
ball acting as seal, was patented in the USA by S. Twitchell in 1883.
3. The third popular alternative was the internal screw top bottle. Unlike
today’s bottles, the thread was on the inside of the bottle neck and an ebonite
or wooden stopper screwed into the neck, with a rubber washer being used
to improve the seal. These types of stoppers were in common usage well
into the 1950s in the UK. Ebonite, an early type of plastic resin material
soon replaced wood, which had a tendency to absorb moisture, causing it
to swell and crack the bottle neck.
A major step forward in sealing development was made by William Painter, who
in 1892 patented the ‘Crown Cork’, founding the Crown Cork and Seal Company
on 1 April 1892. Although initially slow to gain acceptance for two reasons: (a) the
existing large capital investment in returnable bottles and bottling plant, and (b) the
need for a tool to remove the crown, the crown