Preheating the Oven: “The Recipe Says So” myth.

timehastoldme

Just to add, that while pathogens will be destroyed when the oven eventually does get to temperature, that doesn't mean toxins produced by them are destroyed. By giving them a chance to sit at a moderate temperature and multiply, you're also increasing the risk of toxin related illness. 

This is why rice is so iffy, cool it fast and reheat quickly, because while the reheat might kill off any Bacillus cereus, the enterotoxin levels might already be in gut ache level.

Also, anecdote and experience isn't data. Some people have cast iron stomachs or are lucky, others are more fragile. Especially those who are most at risk of diarrhoea related illness (which can be hard to recover from for the vulnerable). Best not to risk it for a few pence.

Green_hopeful

Our oven is a slow heater. Other than cakes or Yorkshire puddings which need the oven to be hot we put the food in from cold. None of us have had food poisoning and often the food is cooked by the time the oven reaches temperature. Saves time and money. Just check the food is cooked through before eating it. Also we cook most things at 160 fan which is the equivalent of 180 in a normal oven. It takes a little bit of judgment but not much, even the kids can tell if a pizza is cooked. 

I often cook at my inlaws house where their modern oven heats up quickly and no issues there although randomly their oven heats more at the bottom than the top so that takes a bit of getting used to. Think that is something to do with the fan. 

When cooking a roast I often add a pudding into the oven half way through and that cooks fine. 

Nickvale

Not so sure about the 'dangerous pathogens' argument. What about oven delay timers? If someone puts a roast in the oven and sets it to come on in a couple of hours, so roast is ready when they get home later, is that dangerous? If so, why no warnings (that I've seen anyway) from manufacturers? 

newlywed

Nickvale said:

Not so sure about the 'dangerous pathogens' argument. What about oven delay timers? If someone puts a roast in the oven and sets it to come on in a couple of hours, so roast is ready when they get home later, is that dangerous? If so, why no warnings (that I've seen anyway) from manufacturers? 

And slow cookers?

MrsStepford

 I'm a college-trained former chef with current food safety certs from FSA and CIEH. My primary concerns are:

1. That food is safe to eat
2. That it isn't spoiled by being cooked incorrectly.

For example, a beef cut that is more suitable for stewing, shouldn't be flash fried like a fresh tender steak. Frozen meat can be damaged by ice crystals exploding in the cells, if cooked from frozen at too high a temperature. If cooking from frozen, you also risk parts of a joint or bird being raw and other parts cooked.

Food safety is more important than saving money. Cooking instructions are there to help you.