Baby cereal

I want to make my own baby oatmeal cereal by buying organic oats and blending them into a powder consistency.

However when we eat oatmeal we use boiling water before consuming it.

Was wondering if I place the powder in my babies bottle is it okay to consume without the boiling part ?

Or when she begins eating it I want use my breast milk however we cannot boil breast milk so will it be okay to consume at room temp just like when you buy the gerber cereal

Thoughts ???...