The dry starter needs few days to be fully active and be able to rise a sour dough, but it may stay at this form for a long time, months or even years. It is mainly dry form of flour mixed previously with water, but contains bacteria ready to work after been activated and fed. There are many starter in the world but only the San Francisco starter has a bacterial strain that has been specifically identified and named as being unique to its region ( http://www.culturesforhealth.com/ ).
Activating the dry starter
1.- day 1 - Put 100 gram of flour and the dry starter to a clean glass glass or a plastic pot, add 30 ml of clean, not chlorine water and mix. Be sure the flour has been moistened and cover it with a lid or a plastic foil. Leave the mixture in room temperature for 2 days.
2 – after 2 days the mixture the mixture should has some bubbles and is probably ready to use as a starter, if not , wait 1 more day.
After 2 days it should shows signs of living.
Now it is ready to use as a starter.