Yes, glass mixing bowls can go in the freezer. Glass is a good conductor of heat and will not break when exposed to extreme cold temperatures. However, it is important to note that glass can become very brittle when frozen, so it is important to be careful when handling frozen glassware. Also, if you are using a glass bowl to mix ingredients that will be frozen, it is important to make sure that the bowl is completely dry before adding the ingredients, as moisture can cause the glass to crack.