I saw Heston Blumenthal the other night on TV with his roast chicken recipe, and I wish I hadn’t. His suggestions really worry me. Leaving aside his recommendation to brine the bird before roasting (because what we all need in our western diets, ladies and gentlemen, is more salt!), he advocates roasting the bird at 90 degrees centigrade (70, even, in a fan oven!) for several hours to a target internal temperature of 60C in the thickest part of the breast. While I have no doubt that this treatment results in a marvellously moist tender bird (it’s barely cooked after all!) the food safety implications of the process are pretty horrifying.
All raw meat is contaminated with bacteria. This is just a fact of life – after all, meat is dead animal, and animals have bacteria in and on them in life which are impossible to remove in the course of processing.
Poultry meat in particular is high risk. A UK study published in 2000 identified Campylobacter jejuni in 83.3% of supermarket chicken that they sampled. I would go as far as to say, I almost guarantee that any raw chicken you purchase will be contaminated with Campylobacter, Salmonella or E. coli, and the risks are probably higher with free range birds which aren’t raised in a sealed environment.
The reason we don’t all have food poisoning all the time is that cooking – the application of heat – is extremely effective in killing these pathogens. Here’s the problem – Salmonella requires a temperature of 60C for 10 minutes to be effectively killed. Campylobacter also needs to get to 60C, though it’s a bit more fragile so a minute or two should do trick. E. coli is more robust – but less common in poultry meat – and needs to be heated to 72C. The universal advice for safe cooking of poultry meat takes all of this into account and advises the thickest (and hence least heated) part of the meat should reach a minimum temperature of 75C for at least 10 minutes.
On these numbers you can see how Heston’s recipe might *just about* not be gastrointestinal suicide, but you would want to be very confident of your temperatures. The trouble is, any error in measurement – if your probe isn’t really in the absolutely coldest part of the bird – is going to read higher than the true lowest temperature, making it very easy to overestimate the minimum temperature and have parts of your bird below 60C.
To be quite honest, I don’t care how tender and succulent this roast bird might end up – it amounts to food hygiene russian roulette! I’ll be staying away from the Fat Duck, I think.
Please, if you want a wonderful succulent roast chicken, buy a good free-range bird with some good fat under the skin, add some lovely flavours in the cavity (I like a quartered lemon with some whole cloves of garlic and a handful of thyme), a little bit of salt and pepper on the skin with a couple of rashers of bacon if you fancy it, and then roast at about 180C to a safe internal temperature. Rest for 20 – 30 minutes before carving, and enjoy a tasty, succulent, and above all safe roast dinner!
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I had the same thoughts exactly. He even said for safety reasons you should opt for a ‘higher internal temperature’ but he finds 60 degrees to be fine. Ive always wondered, his techniques are brilliant dont get me wrong, I love his inventiveness. But after a few food poisoning complaints at his michelin star establishment (last year if I recall) I wonder if safety is being overlooked too much in his cooking methods.
It’s just such a high risk approach – doing it in a professional kitchen with skilled staff and oven thermostats you’ve tested, and thermometer probes you know to be accurate, that’s one thing (but still you should warn people in case they’re pregnant or immunocompromised, if you ask me!). Suggesting that people do this at home in their domestic kitchens, and feed it to their children? That’s just reckless, in my opinion. Really surprised Channel 4 allowed it to air without a major health warning. The brief nod he made on air to the safety advice for 75 degrees doesn’t seem to make it into the online version of the recipe at all, either…
You’re forgetting that the temp will rise 2-5 degrees (or more) while resting for 45 minutes. looking at the chart here http://www.fsis.usda.gov/OPPDE/rdad/FSISNotices/RTE_Poultry_Tables.pdf and using 12% fat conservatively it takes 35 minutes at 140F/60C, 13 minutes at 145F/63C, and 4.2 minutes at 150F/65C to be SAFE! E coli starts dying at 55C, not 72C. 72C is instant pasteurization. The “Universal advice” has a safety margin so wide you’d have to be incompetent to miss it. Done carefully, with knowledge and the right tools its a safe recipe.
I quite agree, actually!
My real concern is the suggestion that this recipe could be appropriate for home cooks to attempt in domestic kitchens. It’s safety depends on being able to be certain, *absolutely certain*, not only that you’ve achieved that target temperature, but that you’ve achieved it in the coldest part of the carcass. The margin of error is non-existent, so accuracy is essential. I’m afraid I personally don’t believe that you’re average home cook, with their potentially less than accurate temperature probe, and their incomplete and inaccurate knowledge of chicken anatomy (most home cooks don’t even portion whole birds, so what do you think the odds are that they’ll reliably find the thickest part of the breast without hitting the keel bone or getting too close to the ribs & cavity?) is going to be able to pull of that absolute certainty of accuracy.
You’re quite correct to say that E. coli kill starts at 55 Celsius, though it’s fairer to think of replication stopping at this temperature since kill at this temperature is so slow it would take almost two hours to achieve it to a level compatible with food hygiene.
Humans are capable of remarkable incompetence – a really wide margin of error in advice on something as critical as food safety seems entirely reasonable and appropriate to me! Remember that people manage to poison themselves with their Christmas turkeys every year. Is the marginal benefit of super-tender chicken worth the risk that people are going to make themselves sick?
In professional hands, yes, OK, this recipe may have some merit. In amateur hands? It’s irresponsible to recommend it, I think.
I respectfully disagree with your opinion about this recipe not being something for the home cook. You usually only worry about Salmonella, since it’s the one pathogen that’s most difficult to kill. It takes about 12 minutes to reduce Salmonella sufficiently at 60 C. And this is the worst case, with a piece of chicken that’s badly infected. It’s very unlikely that you will actually encouter that, especially if the chicken is somewhat fresh. Needless to say, you should use a fairly fresh one 🙂
Even with a bad chicken, the temperature rises quite slowly because of the low setting of the oven. So Salmonella (if present), will actually be reduced by quite a bit already when it hits 60C. Then of course, you let it rest, and the temperature will not drop that fast for a chicken. It will take quite long for the temperature to drop below 60 in the center, since the parts near the surface is hotter than 60C.
I don’t agree with the margin of error being non-existent. Sure you need a fairly accurate probe. But you need that too if you would cook it to 70 C using a hotter oven and not letting it rest. And while you should aim for the thickest part of the breast, a few millimeters off is not crucial. Bringing the chicken to 60C with the oven set to 90 C, and let it rest for 45 minutes, is _not_ to live on the edge. It’s overkill to make the bird safe, actually.
I think home cooks are more than capable of making this dish, wih no issues regarding food safety. You need to understand that the low temperature of the oven, in combination with the proper resting, is the key. And those people who poison themselves with turkey probably uses far more heat for a much shorter amount of time.
But yeah, using a probe that’s off by 5 degrees, cooking an old bird and serving it to someone who’s 90 years old, that’s irresponsible. Otherwise, I wish people would start to cook chicken like this.
Thank you for your considered comment, Dan –
I think basically we’re in agreement, I’m sure slow and low is the right way to get luscious moist meat, but my trust in the competence and carefulness of the average member of the public is obviously less than yours! I’m not at all convinced that the average domestic oven ‘set’ to 90 is anywhere near that (last time I tested a domestic oven with a thermometer I got some very ‘interesting’ results) – with a bit of luck it’s well over, but it could also be well under – and I suspect that if, after a number of hours and lots of anticipation, the person preparing it can find 60 ‘somewhere’ on the bird with the cheap thermometer they’ve picked up, they might be inclined to just ‘go with it’…
Hell’s bells – it’s food and it’s delicious. Take a (tiny and theoretical) risk and enjoy life a little.
I hate food police
Can’t argue with that, I guess! Good to understand the risks that you’re taking, though, rather than crashing around blindly?
I’m sure the average member of the public whom does not even know how to portion a chicken… Would not attempt this (comparatively) lengthy recipe. I’ve used this method with several supermarket chickens (about 6 or so in the last year) and have (fingers crossed) not gotten sick once from it. Considering I am immunosuppressed, I think that this is a pretty good example of how making sure you follow the method to a T, keeps you safe. I don’t go for an internal temp of 62, but 67’C (because I have a meat thermometer with a margin of error I don’t know about >__0).
I wouldn’t say to just go for it if you’re the careless type, but this is entirely doable in a home kitchen!