I pumped directly into these bottles, glass would have been much too heavy to pump at the breast. Freezing works great with these bottles. We used them for 8-9 months, they were top quality, always rinsed in cold water and then washed in the dishwasher. If you don't rinse in cold water first, the milk proteins in the MuMi can "stick" to the heat in the dishwasher.

What exactly do you do with the bottles? We have been using ours for over 10 months without any problems (dishwasher, sterilisation in microwave). We use a separate glass bottle from another manufacturer for the bottles.