I plan on brewing a raspberry Hefeweizen soon. For the raspberry I plan to add about 2 pounds of raspberries to the secondary fermenter for about a week. Will the sugars from the raspberries use up the remaining live yeast cells in the beer? I am concerned about not having yeast available in the beer still when it comes time for bottle conditioning resulting in very little or no carbonation. Should I add any extra yeast for carbonation purposes?