Q&A: Science of the Kitchen

[mrbigjas]

Are people put off by the science stuff? I'd like to include some chemical formulas in the next unit.

Hells no! Go for it.

[formerly grueldelux]

Very interesting stuff, yet again. I'm particularly impressed by how, over the course of your eCGI sections and your memorable blog, you've snuck in practically a whole course on British cookery. Can we hope for such a module in the future?

I find the bit about ground beef very interesting and it makes me wonder if these insights are used in the industry at all. A restaurant could hold pans of burgers in a 140F oven for 4+ hours and then finish on a grill, for example. Perhaps this way you could get a smaller patty to keep the satisfying juiciness of a thick one (I don't know about burgers in England, but in the States there are countless burger variations but also one type that's fairly constant - the basic bar burger, usually at least 8 oz., grilled, basic adornments. I frequently get this type of burger because, in my experience, it's the surest way to get the best beef experience. But the thing is, I don't really like burgers that big. I'd much rather have two smaller ones, say 5 oz patty on a small bun.

Tried to long cook a 5 oz. burger in a couple of ways (sear first, sear at the end etc.) but didn't have much luck because I too couldn't get my oven to give a consistent low temperature (I have a warming drawer that's supposed to range from 100-200 but tops out at 120. I can get it up to 140 if I put the main oven on as well, but the heat isn't consistent.) My winning burger used a pan preheated under the broiler. The burger was then broiled on one side and then held at or near 140F for 4 hours. It was overcooked by the end, but I see the potential.

So how do we get these low temperatures? I assume it's easy in 4-oven AGAs. Do you happen to know if other ranges feature ovens that can go below 200F?

As a stop-gap, there's always electric appliances, I guess. But many slow cookers, roasters etc. only have a couple of settings, so it's hard to know what temperature you're at. The best range I've seen (EDIT - link removed for not ultimately being that interesting. It was a Nesco 4 Quart slow cooker) claims to start at 150F. I suppose you could put a chicken in there for hours at 155F then blast it in the oven to crisp the skin.

Also looking more interesting after reading your piece are devices that control grills and smokers, like this one from bbq guru Some of the products are geared to high end cookers, but it looks like they're adaptable to even cheaper Weber kettles and home made pits.

Even lower and even slower. Thanks.

Edited April 15, 2004 by formerly grueldelux (log)

[Dan Ryan]

Jack, do you mean The Curious Cook? How is it? I've got On Food and Cooking, which is good, but I prefer Barham's as he gives more practical applications. Are you planning to do any material on the confit-style cooking of fish steaks, using flavoured oils heated to 40-whatever degrees? As for the formulae, absolutely, don't hold back.

[jackal10]

What a fascinating post!

I'm sure slow low cooking would improve many a burger.

Your question as to how to achieve 140F consistently is a good one.

Unfortunately many dometic ovens are jsut designed for re-heating or for browning

Maybe we should campaign to have the white goods manufacturer's include this as an option.

Some ovens I have seen do this on "warm", or if you leave the door ajar a bit. However some cut out automatically after 4 hours, as a safety feature.

I have a combined microwave/convection oven that just manages to go to 120F, but the temperature control is a bit erratic.

Some of the better crockpots allow you to set the temperature.

You may be able to use "hay-box" style - heat a large pan of water to 140F, with an internal basin like a double boiler or bain-marie, and then surround it with a lot of insulation, for example put it in a one of those insulated picnic carriers.

[jackal10]

Jack, do you mean The Curious Cook? How is it? I've got On Food and Cooking, which is good, but I prefer Barham's as he gives more practical applications. Are you planning to do any material on the confit-style cooking of fish steaks, using flavoured oils heated to 40-whatever degrees? As for the formulae, absolutely, don't hold back.

McGee's Curious cook is a lot more practical than "On food and Cooking".

For some reason I did not like the Barham as much - I think his target audience was more like catering students, and I was not sure about some of his recipes.

Wolke "What Einstein Told his Cook" is also good (apart from the title) as a collection of essays, more like Steingarten.

Corriher's "Cookwise" is also good, but mostly recipies rather than science

[gsquared]

I have had good success with poaching salmon in olive oil. Heat control is a bit tricky on the stove top, but my oven can do a consistent 50C and that works well.

[ExtraMSG]

I don't know but I would agree that the extra time in the flavoured liquid will increas the flavour. Have you tried of marinating instead? Also 180C seems a little high - you might get a more succulent product at 140C, held there for at least 12 mins.

Sorry, those were F, not C temps. (Although the fact that the method was poaching should have suggested that .) I prefer to cook my chicken to 170 F.

I'm not a big fan of marinating and I think it's unnecessary when poaching.

Wouldn't the slow cooking of fish at 110 degrees be quite dangerous as far as food borne illnesses? It's clearly in the danger zone.

[jackal10]

That is true, but most fish poaching is in a court-bouillon, which is acidic.

If the fish is whole, with the skin unbroken, ther will be very little bacterial contamination of the flesh.

I'm not a micro-biologist, however. Any experts out there?

If the fish is not overcooked, then it cannot have gone over 41C (McGee gives the shrink temperaure of fish protein as 105F)

[balex]

A question about fat. I have done quite a lot of slow cooking of pork (e.g. shoulder) where you cook it at close to 100C which renders off a lot of the fat. I am about to cook a boned rolled rib of beef -- and it has a fair amount of fat around the outside and in a strip in the middle. I am a bit worried that this will still be there after 6 hours at 65C. Is this a problem? Do you need to cut it out when serving/carving?

[jackal10]

A question about fat.  I have done quite a lot of slow cooking of pork (e.g. shoulder) where you cook it at close to 100C which renders off a lot of the fat. I am about to cook a boned rolled rib of beef -- and it has a fair amount of fat around the outside and in a strip in the middle. I am a bit worried that this will still be there after 6 hours at 65C.  Is this a problem? Do you need to cut it out when serving/carving?

The fat is soft and delicious, despite the food police discourraging eating animal fat.

Beef fat melts around 70C/150F, so most of it will still be in place, unlike cooking, say pork shoulder to a higher temperature where the fat melts and lubricates the rather well cooked meat that is pulled into shreds for serving...

Edited April 17, 2004 by jackal10 (log)

[balex]

So my beef turned out very very well, but I felt it was the wrong sort of beef. The joint I was using (from Lidgates in Holland Park) was quite well marbled, and had been tied with a layer of fat around it. This was unnecessary I felt and all melted out in the initial browning. Perhaps a different joint of beef would have been better -- something a bit leaner but still tender. But not too lean, because a lot of the flavour is in the fat.

It seems that what are traditionally the best joints for high temperature roasting aren't necessarily the best for low temp. roasting. Perhaps sirloin?

[jackal10]

Wing rib on the bone is my favourite cut of beef.

[jmcgrath]

You have really started me thinking. Would medium rare beef brisket be a possibility?

You mentioned above that pork shoulder needs to go to a higher temperature. I take it to around 200F for shreding, but is this really necessary?

Jim

[jackal10]

Should be...150F/65C for 6 hours plus. Heston Blumenthal cooks his for 72 hour sealed in a cry-o-vac bag (sous vide).

Pork is traditionally served more well done, although I don't think it needs to. The old argument was that you needed to kill parasites, but that is not really a problem for the majority of the western world

[jmcgrath]

Should be...150F/65C for 6 hours plus. Heston Blumenthal cooks his for 72 hour sealed in a cry-o-vac bag (sous vide).

Pork is traditionally served more well done, although I don't think it needs to. The old argument was that you needed to kill parasites, but that is not really a problem for the majority of the western world

I'll give it a try as soon as things warm up enough. Temperature control on my pit is good enough that I should be able to hold a steady 150F. Because of airflow through the pit, I may have to foil the meat part way through the cooking process to prevent dehydration.

137F is a safe temperature for pork and I normally cook loins to 140 to 142F. It will be interesting to see if I can get collagen breakdown in a shoulder with a long hold at 150F. Common wisdom is that it starts at around 165F.

Jim

[jackal10]

Test half-wy through. If the collagen is not breaking down how you like, then crank up the heat a little...

Some people do this very long cooking with the food sealed in a cry-o-vac (sous-vide) bag. You kinda need to seperae the browning/smoke flavouring phase from the cooking phase. Sealing the meat, once its smoked to our desire, will help stop the dehydration

[chefboy2160]

Jack, Thanks for the great proof on slow cooking . As a restaurant chef this is how I have been doing my roasts for 20 years now. It is what my old german teacher used to say was bullet proof. There is one company that makes a cook hold oven that just rocks. I have not though cooked at 150 as I always set my oven at 200

(yes the lowest temp setting) And we always held at 140 . Well , as I write this I have a 4lb.rib roast working in a 150 oven and I will post my results .

Thanks again as this science of cooking is just awsome............

[jackal10]

Thanks!

Look forward to hearing how it turns out....

[chefboy2160]

Jack, thanks so much again. This boneless rib roast prepared just as you show on this thread was the best piece of beef I have ever had and oh so simple. The roast was 132 when pulled from the oven with a total time in the oven including browning was 5 and a half hours. The hardest thing for me was to find 150 degrees between the warm and 200 marker on my oven.I used an old dial oven thermometer for this and I got it dialed pretty close . When the roast was done what little black spots which were in the roasting pan with the onions made a great au jus . I simply removed the roast and added some beef stock and scraped the pan pretty good while it was over a medium heat . I reduced this and adjusted salt and pepper , strained and voila. Oh and one more thing , the browning gives such a good flavor and contrast to the roast when its sliced.

Well , I am on cloud nine so thanks dude and keep up the good work.....

[jackal10]

As an exoeriment I tried cooking a standing rib roast for 24hours at 60C/140F.

The result was amazingly tender. I thought it perhaps even too tender, loosing some of its essential nature and becoming almost like felt in texture, My dining companion loved it, however.

It may be better with other meats, pulled pork for example or brisket...

[MobyP]

Now we need someone who can sous vide an entire rib roast, and cook it for three days...

[HKDave]

Jack, great info. Thanks. I've played with moderate temperatures (like around 110c) and combi (convection+steam) cooking for roasts recently with good results, but you've convinced me to try to go all the way down to McGee/Blumenthal levels.

I've got a few questions....

I've always thought gigot a sept heures is cooked in a closed casserole to keep it moist. Did you do it this way, or in an open pan? And if open, is the meat drying out?

I use a combi oven, so it can steam, convection, or both - but can't act as a normal non-convection oven. It works great at low temperatures in convection mode (obviously no steam below 100C). How will using convection affect timing at 65c, and potential drying? Seems to me I could be creating a great dehydrator here.

Thanks again. I've got a gigot here that I'm planning on cooking in the next couple of days.....

[jackal10]

I've not found dehydration a problem - maybe for the outside slice but not beyond that. SInce the moisture is not squeezed out from the cells, the meat stays moist. Also a gigot is surrounded by fat, which acts as a seal.

The restaurant answer is sous-vide, sealing the meat in a plastic bag, once browned. Since the temperature is low, the plastic does not melt.However I use a convection oven, but if your oven is not vented I can't see it being a problem.

[guygateau]

It is a good presentation. It is curious that we have a different point of view on a few points and a slight divergence as far as some T° We do advise 70°C for "pasteurization" (20mn)

In the article the appliance of science (Guardian) Hester Blumenthal makes reference to a computer program at Reading University, do you know more about this?

I do mostly the same presentation but with vaccum pack cooking and a particular type of micro wave oven. Waves & steam cooking.

I 'll come back...