Thanks, Liz.

Hi Paul,

Thawing at room temperature is certainly much less safe than in the fridge or cooking straight away, so is generally not recommended – it’s more difficult to control the temperature. As you said, at some point the food will likely become warm enough to allow rapid multiplication of bacteria on the parts that thaw quicker.

Defrosting in the fridge for a specific amount of time (depending on what it is you’re defrosting) is much safer because the food will be held at a cold enough temperature to hinder the growth of bacteria while it thaws (assuming your fridge is kept between 1-5). However, it’ll only hinder it, so this is why it’s important to cook the food as quickly as possible after it’s fully thawed. There is certainly a risk there, but applying appropriate temperature and time control will ensure you keep that risk to a minimum and that the bacteria don’t multiply to a dangerous level. And of course, as mentioned before, you can certainly cook plenty of foods straight from frozen, which also requires good temperature and time control.

Hope that solves the conundrum!

Liz

Thanks, Liz, but that still leaves the conundrum – allowing something to thaw in the fridge or at room temperature, will surely allow bacteria to flourish for longer, as at some point, the outer parts are warm enough to allow bacteria multiplication, and will stay that way for longer, as the inner parts slowly warm up?

Hi Paul,

I completely understand where your thought process is here, and you’re totally right: defrosting/cooking certain frozen foods in boiling water can be perfectly safe. For example, it’s not unreasonable to pour frozen peas into a boiling pot of water and safely cook them, or to add frozen chicken thighs into a boiling pot for soup. This is because they’ll defrost evenly very rapidly.

However, in the case of, say a whole frozen chicken, cooking it in boiling water could prove to be unsafe. This is because the heat of the water may not heat the chicken evenly and quickly enough, particularly the centre of the chicken. So, while its surface may be immediately thawed and at a sufficient temperature to kill bacteria, the centre might not reach this temperature quick enough. Therefore, if you do choose to do it this way, make sure you take extra care. You must ensure that it thaws fully, that you account for the extra time it’ll take to cook through, and you measure the temperature properly with a food thermometer.

You can read more on our guide if you like: http://www.highspeedtraining.co.uk/hub/can-cook-frozen

Hope that clarifies things for you!

Liz