Generally addition of culture is at the rate of 0.5%-3% based on the type of the culture that we take and the product that is to be prepared.
In order to increase the biomass the culture should be is propagated properly and should be in its initial stages of logarithmic phase,which means the growth curve of the culture has to be studied first.
Addition of 2% v/v inoculum would be optimum for cheese production, but the culture should be in active state.
Activity tests( Such as Horral Elliker test) can be carried out to check its ability to produce required acidity with in stipulated time so as to check whether culture is ready for inoculation in to the batch.