Sorry Josema,
But condensation (in our atmosphere) is water changing from a gaseous state to a liquid, which generally occurs on the the outside of something cold (like a glass full of cold ice water).
Joe (Sedici) is correct,
Unless you are running ice water for clutch fluid, what is happening is that over time brake fluid is slowly "sweating" through the brake hose and forming droplets (of brake fluid). on the outside.
The HRC hose is notorious for doing this. I had a Honda factory race bike (RS125) with the same hose and it did the same thing.
The standard Brembo brake hose is black and is made with EPDM rubber (same as brake seals in the master and calipers) and is compatible with brake fluid.
For years I have been trying to purchase the green brake fluid hose that was originally on one of my vintage race bikes (Jimmy Adamo's TT1-F1). Everyone at Brembo that I talked to said that it didn't exist, even though almost every modern MotoGP bike uses it. I don't know where is comes from.
The green brake hose gets hard with time (years) but it doesn't sweat like the HRC stuff does. You can look at fluid compatibility on hose vendor sites and find other tubing that is made of a material that is brake fluid compatible.
http://www.safehose.com/techresources/charts/industrial_hose_chemical_resistance_guide.pdf
If you want clear tubing, I would recommend Tygon tubing.
I see this all the time on vintage cars with separate brake fluid reservoirs were people have installed fuel hose (Nitrile rubber) instead of the original EPDM rubber brake fluid hose.
Brian