I think the curds are too soft, what do I do?

Your curds may be too soft for a number of reasons, but most likely the milk has been through ultra pasteurisation or ultra homogenisation.

1. First, ensure the temperature is correct and being maintained as this will influence the setting process.
2. If the milk is really not setting try adding more rennet and gently stirring this through. Add the same amount of rennet as you already have, therefore doubling it.
3. You may also like to add more culture to try and boost the process but if the temperature is correct then doubling the rennet will have the most impact.
4. Allow an extra 30 minutes then check again.