Hi Alexandra –
Glad to hear your boys like the food 🙂
Freezing won’t have a significant effect on the quality of most of the ingredients – although you may want to wait on adding any vitamin e or fish oil until just prior to feeding (to ensure maximum potency and decrease the risk of oxidation). Also keep in mind that if you use yogurt or kefir some of the probiotics will be killed off during freezing so if you want the maximum benefit from either of these ingredients you may want to wait on these as well. But you could definitely mix up all the meat, whole food supplements and other “extras” ahead of time and freeze.
