Instant formula - mixing/chaining bottles?

[Argh25]

Baby is on powdered Kendamil in the day and instant Kendamil (250ml bottles) at night/travel for sanity reasons.

We're looking to up her feed from 120ml to 150ml, but then that leaves 100ml left in the bottle which isn't enough for the next feed. I fully commit to the amount before serving because my baby is a drama queen and I cannot be arsed to keep going back to the fridge to top up in 30ml increments if she decides she's still peckish.

Is it okay to essentially chain the bottles - so use 150ml for first feed, then 100ml from first bottle + 50ml from a new bottle? Am nervous of All The Bacteria so just want to sanity check. 😂

We open at room temp and then keep in fridge for 24 hours max, and pour away any from drinking bottle she hasn't finished, so can't immediately see issue with this but having doubts now! Wish they just sold them in different sizes but even the 70ml ones are a weird amount (also expensive and wasteful because of the teats 🙄).

TIA!

I would say to save yourself the wastage, just get portioning containers to scoop out your formula before the night / travel. Get either a rapid cool flask or a perfect prep machine. I think the cost of the machine will defo be paid back in what you save overtime with the ready made feeds. As to the topping up when baby is peckish, always make an oz extra than baby actually takes is what I’ve been told by midwife.

Hi - it's just for the instant formula in the nights. I have a rapid cool but at night find the instant easier. 😊 I don't want to use the perfect prep machine, I was lent one but not interested in using it.

So how long will the first bottle have been opened for?

It can be hard keeping track of things like that when your brain is half asleep at night - write what date and time each one was opened on the bottle with a marker pen

So I scribble on the bottles in Sharpie, date time and amount left. Tonight - first bottle opened at 5pm and put in fridge and second bottle 9 hours later. Actually finding it okay to keep track. Just want to know if I can mix different bottles if it's within 24 hours and first has been kept in the fridge?