Bulgaria uses a unique double distillation technology
called "cohobation". It was the result of an attempt
to obtain rose water of a higher quality than otherwise possible.

"Cohobation means simply that the hydrosol or condensed
water that comes of the still is recycled...
Cohobating the hydrosol means that any micro drops of
organic essential oil that were dispersed in the water
have an opportunity to coalesce into drops big enough
to separate into oil, thus improving the overall
yield of the distillation... many of the four hundred plus
chemical compounds are highly water soluble and
the yield of the rose is so low that every drop is extremely
valuable. Uncohobated rose is missing many of the
plants important therapeutic and aromatic compounds
because they stay in the water."¹

¹From the book "Hydrosols: The Next Aromatherapy"
by Suzanne Catty. Healing Arts Press. Rochester, Vermont. 2001 P.28