Why Does Ouzo Turn Cloudy When You Add Water?

Ouzo , the anise - flavored Greek and Cypriot spirit , has a very strange gist , other than create a in particular strong   holiday katzenjammer .

If you pour some pee into this transparent liquid , it will turn a cryptically cloudy white . A new study published in theProceedings of the National Academy of Scienceshas now   explore   the aperient behind this   foreign “ ouzo effect , ” satisfying the wonder of drunkards around the macrocosm .

It all has to do with anise plant oil . This oil is used in many liquors , apéritifs , and spirits to give it that aniseed or licorice - same taste . That ’s also why the “ ouzo effect ” can be seen in other drinks such as absinthe , sambuca , and pastis . The solubility of the oil in the ouzo varies look on the alcohol - water ratio . If you tote up more water to the intermixture , this crude oil solubility decreases . This causes the oil to constitute nano - sized droplets within the liquid ,   which   fuse together to create larger droplet and hence spread out the light entering the liquid , giving it that   nebulose appearance .

Researchers from theUniversity of Twentein the Netherlands studied this by placing a drop of ouzo onto ahydrophobicsurface . The dip initially remains clear and transparent , but eventually the alcohol starts to evaporate , changing the alcohol - water ratio . Most of this alcoholic beverage evaporate at the outer edge of the fall , meaning the   rim starts to turn nebulose first .

A storm is then kicked up in the drop and a procedure of “ rapid movement ” begin . Differences in surface tension induce a comparatively high story of convection – simply put , cause in the drop – through a process known as the “ Marangoni effect . ”   The “ ouzo outcome ” on the rim therefore starts to move inwards to the balance of the drop as the evaporation and movement behave on . finally , all alcoholic beverage evaporates and the liquid returns to its transparent nation .

This whole process lease less than 15 bit at room temperature in a single drop of ouzo . However , it is all sped up in the   video below .

So next time you ’re knocking back a few ouzos , spare a thought for the complex physics going into your draught .