Role of beer in development of colour measurement methodology

The hero of the story is Englishman Joseph Lovibond . He as a teenager went to Australia to try one’s luck in the gold-rush in South Australia. After he had made his fortune he set course back home. As his ship was leaving Sydney Harbour he was waving his friends standing on the wharf so enthusiastically that all his money spun out his hat into the sea[1]. Poor once again, he joined family brewing business. He noticed that colour of the brew is a good indicator of its quality. At that time there was no established system of scale relating colour and quality of the brews. Lovibond started experimenting with pigments paining on to a card holding them against the beer. This was unreliable and unstable way as the colour patches faded away[2]. Nonetheless it is not the way to compare translucent liquid with a painted card. Lovibond’s inspiration arrived one day in Salisbury Cathedral where he realised that the key component for his reliable system assessing beer quality has to be a set stained glasses of right brown shades. Five years later, in 1885, he produced the first colorimeter using many different variations of brown[3]. Later adapted to Lovibond Colour Scale able to measure three primary hues: red, blue, yellow, which caused revolution in the colour testing.

Lovibond’s Colour Scale tintometer held advantage against its competitors laid in ability to generate a system of colour description based on a quantitative numerical index. This enabled its broad deployment in numerous applications in various fields including: metallurgy, petroleum industry, water quality assessment, agricultural grading.[4] Moreover, the Colour Scale was constructed in such way that it was able to attribute colour of opaque test samples as well! These features were superior notwithstanding the constrains of the instrument: (i) uncontrolled variability of the reference light, (ii) extra losses due to multiple reflections and thus error in the determination if several stained glasses had to be used.

Instrument as such being upgraded by replacing the brown stained glassed for filters of colour matching functions as have been defined by CIE (International Commission for Illumination) and build-in a reliable reference light source the tintometer principle still takes place even in contemporary colorimetric measurements. Revelation and interpretation of the key physiological visual mechanisms of colour perception will be object of the coming episodes in our little serial.

Advancements in science and technology require hard work but time-to-time other kind of assistance can occur. History is full of fascinating stories putting a smile on your face in which an accident or a (un-)lucky coincidence played crucial role for discoveries. Remember the apple hitting Newton’s head and thus giving impulse to the gravity law formulation. Here we want to briefly write perhaps less known event in the field of colours that took place at the beginning of construction very successful tintometer or colorimeter in 19th Century. The exotic role in this case is played by beer and stained glass of a cathedral.

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