Can you use a slice of white bread as a yeast source in homemade wine?

You dont use the sucrose( table sugar) and the bread will work. Sugar will accelerate process but fruit has its own. Keep container LOOSE to let gases escape or it will rot, not ferment. Three or four days then drain from top then get rid of sediment and finished in 14. Re do off top for sediments then store a while before drinking for taste.