This is the 6552nd most frequent Polish word.
czystego
"Pure" or "clean" (genitive or accusative singular of "czysty").
The word 'czystego' here functions as an adjective describing the purity or quality of the juice.
Mam szklankę czystego soku.
I have a glass of pure juice.
In this case, 'czystego' emphasizes the cleanliness of the air, indicating it should be free from pollutants or impurities.
Potrzebuję czystego powietrza do oddychania.
I need clean air to breathe.
Here, 'czystego' describes 'alcohol', signifying its uncontaminated state suitable for a specific purpose like disinfection.