Two joints of lamb, one oven - timing....

[ReallyTallTony]

Hello,

For Christmas I have learned I am cooking for an additional 14 (!) people for dinner, we are having lamb as the main roast.

My oven is not big enough to take a large joint of lamb in one piece but could take two smaller joints, one above the other.

My question is, aside from rotating periodically to make sure the cooking is relatively even, is the timing for (example) a single 4KG joint of lamb, the same as two 2kg joints? As once the oven gets back to temperature after the meat is put in, I think the cooking time is the same for any number of 2kg joints put in.

Does this make sense, and can anyone advise?

Many thanks,
Tony (maker of some mean roast potatoes)

 

[Morning Glory]

Hi @ReallyTallTony,
If you are using 2x 2kg joints then you time it for 2 kg of lamb. Swap the lamb around half way through as most ovens have slightly different temperatures at top and bottom. Would like to know how you cook the potatoes.

 

[epicuric]

Mix things up a bit? How about doing a slow cooked shoulder and a medium rare leg joint? You can put the shoulder in low about 5 hours before you need to put the leg in, turn up the heat and brown off the shoulder whilst cooking the leg for the last hour (exact times dependant on weights)Your guests then get a choice of lamb cooked two different ways. Or you could invest in a meat thermometer.

 

[Morning Glory]

Mix things up a bit? How about doing a slow cooked shoulder and a medium rare leg joint? You can put the shoulder in low about 5 hours before you need to put the leg in, turn up the heat and brown off the shoulder whilst cooling the leg. Your guests then get a choice of lamb cooked two different ways

That's a good idea.

 

[GadgetGuy]

My stove & oven is small also.
Strange! I can get a big oval roaster in there, but most larger pans won't fit in it!! Not even my half sheet pans! But it is what it is.

 

[Morning Glory]

View attachment 4302


My stove & oven is small also.
Strange! I can get a big oval roaster in there, but most larger pans won't fit in it!! Not even my half sheet pans! But it is what it is.

You even have an orange tea towel!

 

[Cinisajoy]

We need to paint his dish drainer.

 

[Morning Glory]

We need to paint his dish drainer.

I rather like the grey dish drainer. It works well with orange. But I think that @Shermie needs a pretty bowl of clementines (or tangerines) to complete the picture.

 

[GadgetGuy]

Hah!!!

 

[SatNavSaysStraightOn]

Hello,

For Christmas I have learned I am cooking for an additional 14 (!) people for dinner, we are having lamb as the main roast.

My oven is not big enough to take a large joint of lamb in one piece but could take two smaller joints, one above the other.

My question is, aside from rotating periodically to make sure the cooking is relatively even, is the timing for (example) a single 4KG joint of lamb, the same as two 2kg joints? As once the oven gets back to temperature after the meat is put in, I think the cooking time is the same for any number of 2kg joints put in.

Does this make sense, and can anyone advise?

Many thanks,
Tony (maker of some mean roast potatoes)

No I don't think the timing will be the same for the simple reason that the meat is not a thick to get to the centre. Not sure that made sense but basically a 4kg piece of lamb may be, say 20cm to get to the middle of it, where as a single 2kg piece of lamb may only be same 15cm to get to the centre of it. Thus the centre of the 2kg piece of lamb will heat up more quickly than the 4kg piece and as such take less time to cook.

But you have the additional piece of lamb to take into account. Now I recall, but can not say where, that when you add another item to the oven that is the same size as the first and requiring the same cooking time, you need to add 50% on to the cooking times because the oven now has to heat up twice the quantity.

So the questions become,

• how long does it take for a 2kg piece of lamb to cook?
• How long does a single 4kg piece of lamb take at the same temperature?
• what is the difference between the first + 50% and the second.

I truthfully can not answer that question for you, but with any luck it will put you or someone else on the right path.
@Berties may be able to help and we also have a new member who is a chef as well @Linda_Thompson who may also know the answer (sorry to put you on the hot seat there!)

 

[Morning Glory]

No I don't think the timing will be the same for the simple reason that the meat is not a thick to get to the centre. Not sure that made sense but basically a 4kg piece of lamb may be, say 20cm to get to the middle of it, where as a single 2kg piece of lamb may only be same 15cm to get to the centre of it. Thus the centre of the 2kg piece of lamb will heat up more quickly than the 4kg piece and as such take less time to cook.

But you have the additional piece of lamb to take into account. Now I recall, but can not say where, that when you add another item to the oven that is the same size as the first and requiring the same cooking time, you need to add 50% on to the cooking times because the oven now has to heat up twice the quantity.

So the questions become,

• how long does it take for a 2kg piece of lamb to cook?
• How long does a single 4kg piece of lamb take at the same temperature?
• what is the difference between the first + 50% and the second.

I truthfully can not answer that question for you, but with any luck it will put you or someone else on the right path.
@Berties may be able to help and we also have a new member who is a chef as well @Linda_Thompson who may also know the answer (sorry to put you on the hot seat there!)

I think I answered this above. The timing should be the same for 2 x 2kg joints as it would for 1 x 2kg joint. Why would it take longer? The only issue might be that the oven temperature varies from top to bottom, which is why I suggested swapping them round half way through. I have often cooked 2 chickens at the same time and only time it for 1.

 

[sidevalve]

Just a simple logistical thought - it might be more convenient to cook two pieces of meat anyway. Depending on the size of your table and any seating plans a joint at each end might just be easier to manage.

 

[Morning Glory]

Just a simple logistical thought - it might be more convenient to cook two pieces of meat anyway. Depending on the size of your table and any seating plans a joint at each end might just be easier to manage.

He is cooking two pieces of meat - that was why he was asking....

 

[Cinisajoy]

If I remember correctly, he asked if 2 pieces of 2 kg would require the same cooking time as one 4 kg piece.
I think it would depend on the thickness. If they are the same thickness as the 4 kg, then the cooking time will be about the same. If they are half the thickness then about 1/2 the time.


@morning glory, all chickens are roughly the same size so whether you cook 1 chicken or 3, the cooking time will be the same.

 

[Morning Glory]

If I remember correctly, he asked if 2 pieces of 2 kg would require the same cooking time as one 4 kg piece.
I think it would depend on the thickness. If they are the same thickness as the 4 kg, then the cooking time will be about the same. If they are have the thickness then about 1/2 the time.


@morning glory, all chickens are roughly the same size so whether you cook 1 chicken or 3, the cooking time will be the same.

Didn't understand your last sentence. I'm assuming you meant, 'if they have half the thickness then about half the time)

But I see what you mean. I was assuming both bits of lamb were same size.

Having said that, what is the point in having cooking times per kilo (or pound) which are included in most roast meat recipes, if its going to vary so much between the thickness of the meat....? Now I'm confused!