The bitter almond is the fruit of the almond tree of the species amara (there are also sweet fruits of the species sativa). The bitter almonds contain the glucoside amygdalin and are toxic because of the easily dissociable hydrogen cyanide in larger quantities. From the cores, the bitter almond oil smelling of benzaldehyde and hydrocyanic acid is obtained, which is used in perfumes, pharmaceutical preparations and as a flavoring. In many Italian wines comes as amarognolo (amaro = bitter) tender odor / taste of bitter almonds, which is desired.
There is also one classified as heavy wine faults Bitter almond. This occurs in case of improper use of the blue shade (overblown). The used Ferrocyanide can be split into iron cyanide and into the highly bitter-smelling highly toxic hydrogen cyanide. The causes for this are wrong dosage the blood lye salt, insufficient mixing of the wine after addition of the salt or too slow reaction due to masking of the iron by added complexing,
The Perceptual threshold is from 0.04 mg / l, but this is individually very different and can not be perceived by some people. Therefore, the application of blue tinting is regulated by the strictest of laws. The wine error is expressed by a bitter and sometimes too sour Taste. With a low expression, it is rather inconspicuous and therefore difficult to recognize. If strong, the wine turns blue-green. See also under Black break,