To wish food manufacturers were consistent over cooking from frozen

[shinynewapplesonachristmastree]

Doing a buffet for some relatives this evening. Just got stuff out of freezer which was stuff I'd bought as chilled and then frozen to see it states that this isn't suitable for cooking from frozen and should be defrosted overnight in fridge. Yet identical stuff is sold as frozen items for cooking from frozen.

Im talking macaroni cheese bites, hash browns and mini burgers not a whole chicken . It doesn't make sense.

I've got the things sitting in the kitchen and will just cook a little longer . I can't see that it would be unsafe so can't understand why it says don't cook from frozen . It's going to be ok, isn't it?

If they’re small items I really can’t see a problem. Maybe cover with foil for 2/3 cooking to prevent burning on the outside and just cook slightly hotter and a bit longer

It'll be fine. Make sure it's cooked through properly.

The reason for the differing instructions is to do with how it's made and what it's been tested for. Generally stuff you buy chilled to freeze yourself has been tested for cooking from chilled, not frozen. Things you buy frozen are tested for cooking from frozen.

It will be because they haven't verified it is safe to cook from frozen. That means lab tests will have different safe limits/different tests altogether depending on if its to be cooked from chilled or frozen.

The reason for this is that when you heat from frozen, the food takes longer to pass through the 'danger zone' of temperature where bacteria can grow. So it has more time to grow. Some things produce spores when they are in the danger zone which are not destroyed when the food gets to a 'safe' temperature. So more time for them to do this is obviously bad, and cooking it a bit longer doesn't mitigate that.

Also, when things have been frozen in a factory they have been frozen at much lower temperatures and much more quickly than you can achieve by freezing them at home in a domestic freezer. So again they have spent less time in that 'danger zone'.

The very worst things for growing bacteria are things that have sugars in, dairy, things that have been mushed up and will have little air pockets in, things that are moist, and things with fruit in.

This is all worst case scenario, obviously, and if they had identified pathogens in the batch it would have been recalled. Different bugs have different limits.

The issue is something which was perfectly safe when you pick it up in the shop is 'temperature abused' while you wheel it round the shop, go get petrol/pop into argos/another supermarket/drive home/freeze it slowly in a domestic setting/reheat from frozen at an unverified as safe temperature. There's no way to tell you it's perfectly safe.