Does powdered milk really have to be used up in 4 weeks?

Jessica has been just breastfed for the last 2 months but prior to this she was having a top-up feed of Aptamil. I opened a box of it 2 weeks before I stopped topping her up (as she was gradually drinking less of it and didn't see the point of giving her it any more), which has half of the formula left in it. Now Jess is 19 weeks old and starting to need more again, last night she woke up to feed 3 times- I want to top her up with some formula milk at bedtime to see if this helps her but do I really need to get a new box of formula? This box was opened 9 weeks ago. [/i]

They do say that it has to be used up in 4 weeks as after then then bactia spours start producing in the powder. But I do a mother who gave her baby powdered milk after 6 weeks of openig the box and that bbay never got ill. But again I would say with the box you have being open for 9 weeks then I personally wouldn't use it just incase bactia has formed that you can't see or smell. My LC is on cow and gate infasoy and that also says to discord use after 4 weeks but with her being almost 5 yrs I continue using the milk only because she is older and 1 900g box does her 7 weeks.

But again this is just my personal opinion but I would bin the box and get a new one. Maybe instead of buying powdered milk could you buy some ready made cartons or bottles of milk instead as then you are not wasting powder

The formula milk which i use should be consumed within 3 months from opening or expiry whichever comes first.
dont know about yours ma friend..

I am not a great believer in taking Out of Dates as gospel. But if the milk does make your baby ill then you won't have any comeback against the company. And you have all the extra hassle of looking after a sick baby!

Better be safe than sorry!