"Löyly" is the change in the atmosphere of the sauna after water has been thrown onto the hot stove rocks. It's not a ritual, plus the act of getting the water there is called throwing "löyly". It's rather typical to ask the owner or those with previous experience if a particular sauna has good "löylyt" ("löylyt" is the plural of "löyly"). Because how one experiences the "löyly" greatly depends on the construction of the sauna and the stove. Especially small electric stove saunas can have too sharp "löyly", whereas an old-school smoke sauna with a huge stove has the best, very soft and gentle "löyly". Naturally all of this also depends on the individual as well, just like some love very hot sauna, others prefer more moderate temperatures.