In the ISO standards there are two types of glasses that are standardised. First is the ISO 3591:1977 glass which looks like this.
I have blogged about this glass before in this blog.
The only other ISO standardised tasting glass is a glass intended to taste Olive Oil. Yes you read it correctly. It looks like this.
It is also blue or “dark” in colour as prescribed by the standard. The italic text below gives information about the conditions that apply to this glass according to the standard.
This International Standard specifies the characteristics of a glass intended for use in the sensory analysis of the organoleptic attributes of odour, taste and flavour of virgin olive oils, for the classification of such oils. The glass is not intended for the analysis of the colour or texture of olive oils. In addition, it describes an adapted heating unit used to reach and maintain the right temperature for this analysis.
2 Description of the glass
The optimum characteristics desirable in a piece of apparatus of this kind can be specified as follows:
a) maximum steadiness, to prevent the glass from tilting and the oil from being spilled;
b) a base that easily fits the indentations of the heating unit so that the bottom of the glass is evenly heated;
c) a narrow mouth, which helps to concentrate the odours and facilitates their identification;
d) made of dark-coloured glass to prevent the taster from perceiving the colour of the oil, thus eliminating any prejudices and impeding the possible formation of biases or tendencies that might affect the objectivity of the determination.
The glass, shown in Annex A, shall have the following dimensions:
- Total capacity 130 ml ± 10 ml
- Total height 60 mm ± 1 mm
- Diameter of mouth 50 mm ± 1 mm
- Diameter of glass at its widest 70 mm ± 1 mm
- Base diameter 35 mm ± 1 mm
- Thickness of glass on sides 1,5 mm ± 0,2 mm
- Thickness of glass base 5 mm ± 1 mm
Each glass shall be equipped with a watch-glass, the diameter of which shall be 10 mm larger than the mouth of the glass. This watch-glass shall be used as a cover to prevent the loss of aroma and the entry of dust.
2.3 Manufacturing characteristics
The glass shall be made of resistant glass. It shall be dark coloured so that the colour of its contents cannot be discerned, and shall be free from scratches or bubbles.
The rim shall be even, smooth and flanged.
The glass shall be annealed so that it withstands the temperature changes it has to undergo in the tests.
2.4 Instructions for use
The glasses shall be cleaned using unperfumed soap or detergent and shall then be rinsed repeatedly until the cleaning agent has been totally eliminated. The final rinse shall be with distilled water, after which the glasses shall be left to drain and then dried in a desiccation stove.
Neither concentrated acids nor chromic acid mixtures shall be used.
The glasses shall be kept in the stove until required for use, or shall be kept in a cupboard in which they shall be protected from contamination by any extraneous odours.
The dimensions of this glass are given in Annex A. Like the ISO 3591:1977 glass this glass is also “under dimensioned” from an engineering point of view. The inner radii are not given. Also the height where the thickness of the glass should be 1,5 mm is not indicated.
What this text gives us is information how it should be used. How it should be cleaned.
Some of you will think:”hey, I know this glass!”. I had the same thought and I looked up the glasses that reminded me of this glass.
So, apparently there are only two ISO standardised glasses around in the ISO standards.
All the other glasses like the Norlan, Clencairn etc, etc, are not based on ISO standards. Does that make them unsuited? Nope! It just means they did not get an ISO standard!