Since I had twins, I was lucky enough to have the Department of Public Health send a nurse to my home after giving birth. I learned something interesting.
For newborns, liquid formula is recommended (either ready to use or concentrated). If concentrated you mix it with boiled water to maintain sterility.
Since Sawyer didn’t start on formula until I went back to work when he was eight months old, we gave him powder formula. We are always careful to.use boiled water. We would boil a kettle’s worth and then have it on hand to mix bottles. Turns out we were doing it wrong. Powdered formula is not sterile. So it must be mixed with boiling water in order to sterilize it. So preboiled water is no good. The water is sterile but the powder is not.
Something to keep in mind if you use formula.