07 December 2013

More On Food Safety, Internal Temperature, and Pathogens

or possibly moron food safety:

I'm really not bothered. I have never gotten sick from my own cooking and very, very rarely from restaurant cooking. I use raw eggs all the time. You can pasteurise eggs by holding them at 57C  internal for two hours. The proteins haven't denatured so it still looks and works exactly like a raw egg. I never do that because I use good eggs and also don't care. YMMV.

I eat rare beef, pink pork, pink poultry. I love oysters. I've gotten violently ill from bad oysters but they are worth it. I've gotten sick a few times from restaurant food. This can be down to poor hygiene by the food handlers or it can be from bad ingredients improperly cooked or tainted raw veg.

If you are nervous about food pathogens for whatever reason -- and some people have very good reason to be --  but still don't want to overcook things, definitely study the pathogens, study the time vs. temp data, get a good thermometer, and be disciplined in your cooking.

Cooking to Internal Temperatures: Duration Matters



I don't remember where I found this chart [apologies, kudos, and thanks to the originator] but it illustrates a key concept in cooking that many home cooks are ignorant of: "safe" internal temperatures when cooking depend on duration.

Usually "official" recommendations for food cooking give just a temp at which most pathogens would perish instantly and at which the taste and texture of your food also perish instantly. The government doesn't care how your food tastes, they are optimizing for reduced illness. And companies don't want to get sued because you got sick. I don't want to get sick, either, but I'm honestly not that bothered. I do want my food to taste good and I don't want to go to the expense of sourcing really good meat to eat only to ruin it by cooking it too long.

The chart above is a simplification. The poultry curve is for salmonella. Certainly there are other pathogens that might be in poultry. And I've looked at the raw [heh heh] data from FSIS, and the other simplification is that the curve changes depending on factors such as %fat of the poultry in question. But the chart is perfect for illustrating the temperature and time aspect of cooking safely.

So the FDA says to cook your chicken or turkey to internal of 165F, which is horrible thing to do to a good breast. On the previous post, Joe mentioned he got much better results cooking to 160F (for 3min).  A few degrees can make a big difference. So can a few minutes.

What the chart tells me is that if, say, I'm smoking chicken at a relatively low temperature, and thus it is taking a long while to cook, and if the lowest internal temp is 62.5C at a given checkpoint, I can pull it off in 15 minutes regardless of what the internal temp is then. So if I wanted to take it off the heat at 65C, I would go with either 65C or 15 minutes elapsed, whichever comes first.

Cooking isn't always about the lowest temperature possible. For delicate items or ones that dry out easily -- poultry white meat, pork loin, good steak, most fish -- I err on the low side. For other items, I cook them to much higher temperatures not out of safety concerns but because I think they are better that way. Best examples: goose leg confit (all poultry legs, for that matter), pork shoulder (pulled pork), various braising cuts and such.

Bottom line: if you want to avoid overcooking a particular piece of meat, think of duration when it comes to internal temperatures.

There's plenty of good information on the web about food safety. Douglas Baldwin, for example, has a really nice introduction to it, written as part of a sous vide primer but of good general interest.

01 December 2013

Sous Vide Turkey Breast

For Thanksgiving this year I cooked the turkey breasts sous vide, to rave reviews and enthusiastic overconsumption. For years I've been cooking the breasts and legs separately, usually roasting the breats on the bone. Last year for boxing day I also tried an herb-brined smoked turkey breast on the bone, which was excellent. This year for thanksgiving I broke down the turkeys, made stock out of the backs, breastbones, and wings, separated legs and thighs and roasted those, brined the boneless breasts, then cooked them sous vide before finishing under the broiler with plenty of butter.  I plan on doing the same next year.

I used boneless breasts from 2 turkeys.

brine overnight, about 15-16 hours
from Ruhlman & Polcyn's Charcuterie:4l water
350g salt
125g sugar
42g pink salt
2 bunches fresh tarragon
5 cloves garlic, crushed with flat of knife
a couple bay leaves
20g black peppercorns
(note for next year: some sage and/or rosemary might be nice)

rinse, dry, & bag each with a hunk of butter then cook sous vide @ 61C for 3.5 - 4 hours

To finish, coat with butter and put under broiler, skin side up, until skin is dark brown and crispy.

Chocolate Ice Cream using Cocoa, Assured Nut-Free

I wanted to make a nice chocolate dessert for one of our Thanksgiving guests who is highly nut-allergic but I could not find any brand of chocolate bar that was willing to put a stake in the ground about being nut-free. I did find that Bournville [a Cadbury brand] cocoa is assuredly nut-free, so went with that.

I really wanted to try a chocolate ice cream but I lost patience about 90 seconds into googling. Every chocolate ice cream recipe with cocoa also had chocolate in it. So I invented my own. It was really good, and very well received. Here it is:

125g cocoa
400ml whole milk, used in 2 portions, 220ml + 180ml
400ml double cream
200g sugar
5 egg yolks, beaten
1t vanilla
pinch salt

(1) in large bowl, mix 125g cocoa & 220ml cold whole milk together into a smooth paste
(2) it's hard to resist tasting it at this point, so go ahead
(3) immediately regret tasting it
(4) heat the remaining 180ml of milk + the double cream, off heat at or before it reaches boil
(5) whisk hot milk/cream into the cocoa/milk mix (if this doesn't combine well for any reason, it should be fine to return it to low heat and stir until smooth consistency)
(6) whisk in the sugar & a pinch of salt
(6) whisk in the egg yolks & vanilla
(7) strain into a clean bowl, thoroughly chill, then put it into your ice cream maker