Sensitive crystallization

Cristallizzazione sensibile

Sensitive crystallization

Sensitive crystallization is a method for determining the quality of a product by visualising its “life force”. Going into more detail, the phenomenon was described for the first time by E. Pfeiffer in the 1930s as the capacity of organic substances to affect the growth and spatial arrangement of inorganic salts in a specific and reproducible way; this leads to an obvious variation in the morphology of the crystals. What is interesting to observe is the difference in crystallization between products of the same type but in a different “biological state” (excellent quality products and others that have suffered some sort of stress). These differences of condition are transformed into a different configuration of the crystals in terms of fluidity, order, arrangement of the branches, etc. The image of the crystallization of a product can therefore tell us a great deal about the vitality of the organic substances in that product and consequently about its quality.

The Association for Sensitive Crystallization of Andalo Valtellino (Sondrio, Italy) carried out a number of tests on various samples of beer: Italian and foreign craft beers with low and high alcoholic strength were analysed and the results compared with those of an industrial beer and those of Oppale and Audace produced by 32 Via dei birrai.

Test results clearly show the quality of the 32 beers.

Craft beers with low alcoholic strength

Top fermented Belgian craft beer (alcohol content 5% vol.)

Well-composed, orderly and dynamic image. Well-defined nucleus, robust and well-divided branches. It is possible, however, to see a certain lack of definition of the primary branches and in particular a “stress drop” towards the edges, where the finest crystals seem to fade away. The results would seem to indicate a beer of quality produced with a meticulous method but starting from ingredients that have been poorly selected, if at all.

Oppale (5.5% vol.)

Compared to the preceding beer, the definition of the primary branches and the continuity of the secondary branches as far as the outer edge are clear. The quality is undoubtedly better.

Craft beers with high alcoholic strength

Italian craft beer (8% vol.)

Schematic, rigid, static and weak image. The centre coincides with the geometric centre of the crystallization field. The primary branches are not defined while the secondary ones are short and rigid.

Top-fermented Belgian craft beer (8.5 % vol.)

Better image than the preceding one with regard to location of the centre of crystallization and the development of the primary branches. All the defects, however, remain and it is also possible to see agglomerates of unprocessed organic matter.

Italian craft beer (8% vol.)

Weak image in the overall structure and highly unstable in the local expressions. Rigid and poorly defined primary branches, short, fragmentary and interrupted secondary branches. The recipe for this beer also includes the addition of many condiments and additives, which in themselves do not obviously contribute to a basic improvement in quality.

AUDACE (8.4% vol.)

Detailed and harmonious image with well-defined branches extending right to the circumference. Clearly superior quality compared to the preceding crystallizations.

Industrial beer

Double fermented industrial beer

The difference in respect of all the preceding craft beers is clear. Completely static and weak crystallization, insufficient for an expression of product vitality.


In conclusion, leaving aside the abyss between the industrial and the craft beers, the crystallization images of Birra 32 Oppale and Birra 32 Audace clearly show a higher quality than the other craft beers, alcoholic strength being equal. Compared to the 32 beers, all the others show an active quality potential, which is obviously due to the good preparation and short preservation of the beers, yet at the same time a series of negative effects (mainly lack of definition of the primary branches, poor or no development of the secondary branches, energy “drop” at the edges of the figures, etc.), in all probability due to the poor quality of the basic ingredients.

The opinion of Maurizio Peruzzi, from the Association for Sensitive Crystallization, is therefore that the 32 beer “maintains the life forces of the basic ingredients from which it has been produced almost intact and appears to be a high quality foodstuff among medium-high end, if not indeed very high, congener products”.