Margen
Take half a kilo of meat out of the freezer tonight, drop it in a bowl of cold tap water and in half an hour it can be ready. The same packet, left on the worktop since the morning, takes hours without anyone knowing how many, and it is the only one of the two methods that the United States Department of Agriculture refuses to recommend.
The worktop deceives you because you touch it. At midday the packet feels soft on the outside and you assume the inside is the same. Air conducts heat about 25 times worse than water: while the heart of the piece is still a block of ice, the outer layer has been lukewarm for hours.
Lukewarm means between 4 and 60 degrees Celsius, the band in which the bacteria behind food poisoning multiply happily. That is why the ceiling in every manual is two hours out of the fridge, dropping to one hour when the room goes above 32 degrees Celsius. A packet that has spent six hours on the worktop has spent five and a half too many in the part you are going to eat.
The USDA's official sheet on the matter — it is called “The Big Thaw” — allows only three routes, and the worktop is none of the three. Here they are, in order of urgency.
1. COLD WATER — dinner in 40 minutes
Check that the packaging is sealed and not leaking. If there is a cut in it, move it to a zip-seal bag and press the air out: water getting in spoils the texture and drags in whatever is sitting in the sink.
Fill a bowl with cold tap water and submerge the packet completely. If it floats, put a plate on top to hold it under, without opening it or piercing it.
Set the alarm for 30 minutes if it is a flat packet of steaks or mince, and count on up to an hour if the piece is thick. That is the rate the USDA gives: half an hour per half kilo, and a bit more when the bulk is in charge.
Change the water every 30 minutes. The water around the food cools down, stops transmitting and the process stalls.
Do not use lukewarm water to go faster. Water at a temperature that feels pleasant on the hand puts the surface into the bad band while the centre is still solid, and starts cooking the edges into the bargain.
At the half-hour mark, press the centre through the plastic. If you still find a rigid core, change the water and give it ten minutes more. For the 600 grams of an ordinary dinner, those ten minutes are usually exactly what is missing.
The moment it gives, into the pan. Anything thawed in cold water is cooked straight away: you cannot keep it for the next day.
2. MICROWAVE — you want it right now
Take off any metal tray or wire tie, move the food to a suitable container and use the defrost programme, with the weight entered if the machine asks for it. Stop it two or three times to turn the piece over and separate anything that has stuck together.
The microwave heats in patches: it leaves the edges warm, sometimes half cooked, while the inside still has ice in it. So, as with the water, you cook it immediately afterwards. Defrosting in the microwave and putting it back in the fridge for the evening combines the drawbacks of both.
3. FRIDGE — you have a day ahead of you
Put the food on a deep plate or a dish, on the bottom shelf, and count on about 24 hours per two kilos. The plate catches the liquid it releases and stops it dripping onto whatever is underneath.
It is the safest, because the whole piece stays at refrigeration temperature the entire time, and the only one that lets you change your plans: anything thawed in the fridge keeps another couple of days in there and can be refrozen without being cooked.
A whole chicken or a thick piece may ask for more than a day.
All three methods take for granted that the packet went into the freezer in the right shape. Half a kilo rolled into a ball takes a good deal more than twice as long as that same half kilo flattened to two fingers thick, because what counts is the surface touching the water, not the weight.
When you get back from the supermarket, flatten the meat inside the bag until it lies flat, press the air out, write the date on it with a marker pen and freeze it like that. Next month's dinner will cost you fifteen minutes in a bowl.