Black scabs, 5 days post beard transplant. Will they fall all by them self? On which day?

It is best to contact your doctor about post operative care and instructions since each doctor has a different regimen.  You may not be washing your face as well as your doctor may have instructed.

You may start to wash your transplant area at second day of surgery with care and massage the transplant area gently so the scabs will fall off... After two weeks of hair transplantation  it is acceptable  to wash hairs as normal /preoperative period of surgery. All scabs should be cleaned with pressured (not gentle) massage to transplant area  after 2 weeks 

The black scabs are expected after Hair transplant. They typically fall off 5-10 days after the procedure. I advise against removing them yourself as that may pull out the transplanted grafts. Taking warm showers,without letting the shower stream hit the transplanted area directly, will help loosen the scabs and make them fall off faster.

An beard transplant is treated just like a regular hair transplant with regard to the recipient area and along with the donor area requires daily washing with soap and water. Within 3 days of surgery, I tell my patients that they can resume full activities, heavy exercises if they wish. The recipient area requires daily washes as well to keep the recipient area free of crusts. I generally recommend the use of a sponge and supply my patient with a surgical sponge to fill with soapy water and press on the recipient area daily. By repeating this daily, all crusts can be washed off without any fear of losing grafts and you should be clean of crusts within a day. IF any crust is present, use a Q tip and dip it into soapy water, and roll it on the crusts and that will lift them off without dislodging them, but never rub them, just roll the Q tip on the recipient crust. I like to see no evidence of any crusting in the recipient area and the crusts from the donor area gone in 7-10 days with daily washing

You can start to wash the graftsed area the next day after the procedure. The scans should get loose and start to fall off after a few days.