wiki 是个宝阿，上面解释的特别详细。


http://en.wikipedia.org/wiki/Rose_oil





摘抄一下：


Rose Otto， 也叫Attar of roses，指的是一种蒸馏方式，第一道蒸馏产生的精油，rose oil，占总产量的２０％，但不含水溶性物质，尤其是“ phenyl ethyl alcohol ”，which are a vital component of the aroma。为了使玫瑰气味，功效，完整，所以会有第二次蒸馏，其成品占８0％，两次和在一起，才称为Rose Otto。





Attar of roses was once made in India, Persia, Syria, and the Ottoman
Empire. The Rose Valley in Bulgaria, near
the town of Kazanlak, is among the major producers of attar of roses in the world.



所以，并不是只有Rose Valley in Bulgaria出的才是Rose Otto