We have 2 media bottles: 10L and 5L , autoclavable glass with screw-on high-temp caps. We are trying to autoclave about 12kg of Carbomer solution. 2 Questions: Some people say to leave 25% head space for boiling over, some people say 50% head space. Since we need about 12L solution autoclaved and only have 15L of glass volume, what's the optimal filling of each media bottle. My guess is 8L solution in the 10L MB, and 4L in the 5L MB - is that pushing it? Could I potentially lose a lot of solution by doing this? Or should I just use a 20L glass carboy with a foil lid? Thanks. The lead chemist wants to autoclave at 126C for 30 minutes. I'm concerned with the extra high temperature and longer duration will affect the rheological properties of the carbomer solution (e.g. make it more viscous, etc). I believe 121C at 20 minutes would be enough time for a proper sterilization... then recently I read that solution volumes should positively correlate with exposure times, (e.g. larger volume = longer exposure time). Hence my question, we have 5 options. 126C, 123C, 121C? for 30 or 20 minutes? I'm leaning towards, 121C/30min. Thanks for reading - and I hope everyone can learn from this discussion.