Well, I'm pleased. I'm making montasio today using the calf rennet. After getting the IMCU value of my calf rennet (280), and knowning that my 750 IMCU strength rennet uses 0.6 ml to get me in the 10-15 min floc zone, did a simple calculation (0.6 * 750/280) to convert this to 1.6 ml. I used that, and my floc time was 12:30! Had I used the recommended amount of 3ml/10L, that would have floc'd way too quick.