Saturday, February 12, 2011


I have this thing about accuracy. Tomorrow I'm roasting a prime sirloin joint of beef. It weighs 1.045kg. It requires 30 mins per 450g plus 30 mins. How long shall I cook it?
The brains are watching an old Randolph Scott movie.


OldOldLady Of The Hills said...

I haven't a clue....! I hope someone else can help you with this problem, my dear....I don't understand these! (My brains must be watching Randolph Scott, too...!)

Eryl said...

For utter accuracy you need a meat thermometer which would tell you exactly when it's cooked to your liking: rare, medium, well done, etc. Domestic ovens are notoriously inaccurate so I should cook it for an hour and a half and then check for donness by pressing and scewering. Bouncy means rare as do red juices running out. If it's too rare add ten minutes and check again, but remember that it will continue to cook for a while once it's out of the oven. One important thing is to make sure it's not fridge cold when you put it in the oven or it will take much longer to cook.

mapstew said...

What Eryl said! (She got there while I was doing my sums!)

Enjoy! (Will there be yorkshires and proper gravy?) :¬)


john.g. said...

Eryl has it nailed!! If it's rare, i'm on my way!

Pat said...

Naomi: not to worry - there are excellent brains out there and we have other qualities:)

Eryl: not UTTER accuracy. I don't use a meat thermometer and it's an Aga which rarely disappoints. I'm really quite simple and just want to follow the instructions so my question is from the times and weights they have given what is the calculated time. Once I'm sure of that the old experienced cook takes over and I'm confident all will be well. Good tip about the fridge.

Mapstew and John: I notice nobody has done the sum!!!!!!
There will be gravy , Yorkshires, sprouts, carrrots and horse radish and roast potatoes which I shall be careful not to parboil too long. Not too rare John:)

Queenie said...

Takes deep breath.

1045g divided by 450g is 2.322222

30 mins x 2.3222 is 69.66666 mins (i.e. 70 mins, near enough)

70 mins + 30 mins is 100 mins

So if you cook it for 100 mins, i.e. 1 hr 40 mins, that should be about right.

All workings included in case anyone wants to check - I'm getting better at this, after facing my numerical fears last year, but am still not 100% confident.

Good luck, I hope it tastes good, and now if anything goes wrong you can blame me!!!

R. Sherman said...

Queenie got the math right, but I agree with Eryl: Use a meat thermometer, because the temperature determines the level of done-ness. Also remember, the meat will continue to cook after it's removed from the oven for about 20 minutes raising the temperature between five to 10 degrees Fahrenheit. I usually take a beef roast out when the temp is 7 degrees lower than I want it and let it rest for 20 minutes before carving.

Good luck, and


R. Sherman said...

Upon further reflection, I think 100 minutes is too long. The calculation:

1.045 / .450 = 2.32222, i.e. that's the number of 450 gram units in the roast.

That number, i.e. 2.3222 units times 30 minutes is 69.99 minutes for the roast. You don't need the extra half hour, unless it's out of the oven resting.


Pat said...

Queenie: thank you that's what I wanted; numbers that I can be creative with- a good sound base.
And brilliantly done!

RANDALL: I haven't ever used a meat thermometer and am fairly confident I don't need to start. Thank you for the calculation and useful tips. At the moment I am thinking: in the Aga for an hour and ten minutes, examine it and put it back for a while or leave on top of stove for a while - which I would do in any case. In the final analysis I find decades of cooking comes to my rescue and as long as I don't drop the roasting tin all should be well:)

Mike and Ann said...

Hello Pat. Doing the sums very quickly in my head I make it about an hour and a half. I think I'd rely on your experience, though, to check it before the hour and a half is up, and until it looks, smells, and feels 'done'.
Warm regards, Mike.

The Unbearable Banishment said...

I knew Eryl would have the answer. I'm USELESS for such things. But I can find you a nice first edition of a Graham Greene novel at a good price or recommend what to see in New York. Admittedly, neither talent is as useful, but that's what I have to offer.

angryparsnip said...

I am not sure I can pack get a flight and be at your table in time for what sounds like a most fabulous dinner...
I can only dream !
Daughter is a huge Randolph Scott fan, as I am, she found his movies while at University, so I had no influence over her. One of her friend loves and has a blog about old movies.

Have a fabulous dinner and isn't Eryl quite fabulous too !

cheers, parsnip

Z said...

I translate the kilos into pounds, it's easier. And for a small joint I use the given timing, but the larger the joint, the less time per pound it needs. Our Christmas beef, for instance, was perfect at 10 minutes per pound plus resting.

Pat said...

Mike and Ann: yes I think that is absolutely spot on!

UB: books are every bit as important as beef:)

Parsnip: yes Eryl is truly fab! How nice that Randolph has aged well and his attraction transcends generations. I'll pull up an extra chair in case you make it.

Z: honey how do you translate kilos into pounds? That is my problem. I knew you'd be able to crack it.

Z said...

I'm going to make this sound like more trouble than it is to remember - in general terms, double the kilos and add 10%. But when it's an awkward little amount like an extra 45 grams, remember that's not much, only about an ounce and a half, so you don't have to worry too much. In cooking time, it would make more difference putting the joint in the oven straight out of the fridge, or at room temperature, or having a long thin or short fat joint.

Think in round numbers. About 450g=1lb, and 100g=3 1/2 oz. 30g is about an ounce. You don't need to be totally accurate, just get sums you can remember and deal with.

So, I'd look at 1.045 and think '900g is 2 lbs. 100g is 3 1/2 oz. 45g is 1 1/2 oz, add that up and I've got 2 lb 5 oz - that is, 2 1/3 lbs"

It sounds fiddly, but breaking it down like that makes it comprehensible. I couldn't do 1.045 / .450 = 2.32222 in my head. Bear in mind that 20g or so really doesn't make any difference either way, it's a tiny amount.

Pat said...

Z: that makes good sense. I'll print it out and keep it close by my person. It's the short cuts that make life possible. Many thanks:)

kenju said...

Like Naomi, I haven't a clue either!I sure hope someone does.

lom said...

Who would have thought cooking a roast was so hard. I must admit, I just throw mine in the oven and wait, heehee.

enjoy, is there crumble for pud?

Pat said...

Judy: all OK - as usual bloggers come up trumps;)

LOM: it is silly isn't it? I'm just out of practice and given myself angst. But I have everything prepared - a time table and now it's in the lap of the gods.
Not crumble - gooseberry fool - younger son's favourite.

Guyana-Gyal said...

Your 'thing for accuracy' reflects mine so you should see me grinning, Pat.

Pat said...

GG: don't you just hate it when people 'round things up.'