Using an Infrared Thermometer

[gsevelle]

Help,

Most recipies I have call for using an instant read thermometer for internal tempeture. This requires poking a hole in what ever meat or sausage I'm cooking that day. Now with my meat with a hole in it I'm loosing juice, which in turn means I'm drying out my meat and loosing flavor. As an alternative to poking a hole in my meat I've been using my Infrared Thermometer and taking reading of the external temps. Now my real question is how can I convert the recommended internal temps to what the surface temperature should be? Yes I know there will be some variability due to the thickness of the cut or the diameter of the sausage so I'm looking for a general guidline.

Any thoughts and suggestions would be greatly appreciated.

George

[grisell]

The answer is simple: You can't!

[grisell]

Actually, it's quite obvious. For example:

If you put a large roast beef in a 200 F oven for twelve hours, it will be 200 F on the outside (colourless) and 200 F on the inside (=overcooked).

If you put it in a 550 F oven for one hour, it will be maybe 350 F on the outside (burnt) and maybe 80 F internally (=raw).

[dorsets21]

i use a large spud to get a rough idea as to when the product is about done as not to put a hole in to soon, works for me once you have that off pat you can set your watch by it i do pepperoni which take 6 hours to get to temp so i now that at 5 hours 50 minutes i can test 155 every time done

[gsevelle]

Actually, it's quite obvious. For example:

If you put a large roast beef in a 200 F oven for twelve hours, it will be 200 F on the outside (colourless) and 200 F on the inside (=overcooked).

If you put it in a 550 F oven for one hour, it will be maybe 350 F on the outside (burnt) and maybe 80 F internally (=raw).

You are correct is one respect. The longer you cook something the internal and external temps will approach each other, assumming you are using some form of radiant heat i.e. you are not microwaving your meat. Yes I find that when I cook a Texas brisket or pastrami for 8 to 12 hours I normally remove the meat when the external temp is around 155° F. the internal temps will be between 160°F and 175°F depending on which end of the meat I'm testing, the thick part or the thin part. Sausage is a bit different though as I normally don't smoke them for more than 3 to 4 hours. Most sausage I make I use a casing size between 32 MM to 40MM so they are pretty much the same thickness. When I read the Infrared I look for between the 155°F to 165°F and that seems to hit it just about right.

Someone out there has got the be using this method as it has become a propular tool to use in resturants to check temps on foods in steam and ice trays. Again I'm just looking for some guidlines I know there is not going to be a hard and fast formula as there are too many variables.

[grisell]

Okay. I may have misunderstood you.

Are you looking for cooking times per lb, then?

[gsevelle]

Are you looking for cooking times per lb, then?

No I think you got my drift. I'm trying to figure out how I can use my Infrard in lieu of poking a hole in my meat and using the instant read.

George

[Wunderdave]

The amount of juice and flavor you lose by poking a hole in meat is pretty insignificant, and when compared to the amount you'd lose by overcooking something, it's fairly nil.

If we're talking about whole muscle roasts here, the juices you're worried about (in a properly cooked roast) are bound within and between the muscle fibers. There's not a non-permeable membrane on the surface of a piece of meat that keeps those juices in. In a way, you're sliding a temperature probe between the muscle fibers. Some juices might escape just because you create a route for them to gather and run out, but it's not that big of a deal.

When you cook meat, the muscle fibers contract. That's why a pork chop curls when you fry it on a griddle. The same principle applies to overcooking, but to a greater extreme and throughout the meat. This essentially squeezes the moisture that was in them out, and that's why overcooked meat dries out.

Now, if you're talking about sausages in casings, some juices will certainly escape if you pierce the casing. However, hopefully you're cooking more than one at a time, and you can "sacrifice" one sausage. The other way to test sausage with a probe thermometer is to insert it in the end of the link, where the next sausage would've attached. There will naturally be a hole there, and you won't have to pierce to the casing.

As to your question, there's no way to measure the internal temperature of meat using the surface temperature without serious data and math about the cooking medium, cooking time, the size of meat, and the type of meat. Even different pieces of the same type of cut will have different thermal characteristics depending on the marbling and other properties of the meat tissue you're cooking.

Either learn the timing or learn the tactile properties of a properly cooked piece of meat, or use your probe thermometer and don't worry about the half CC of juices that escape. That half CC is nothing compared to what you would lose by overcooking or by failing to rest before slicing.

[gsevelle]

Wunderdave, thanks for the analysis and insight I had not thought about it in those terms. As far as large pieces of meat along with single cuts go I'm pretty good at cooking those. It is not uncommon for me to do three or four whole ribeye roast at a time and I have even done four whole pigs with dress weights from 60 to 110 lbs. (not all at one time).

My taste preferences for beef and lamb tend to run in the rare (cold center) zone and I will normally cook these cuts to a combo of rare to medium rare. If some one wants it more well done I will either cut off and put back or give them the end cuts.

As for my sausage I've had good luck following the process I outlined above but I do agree with you that the internal prob is probably the best way to go. And you are correct I really do not loose that much juice out of one sausage.

Thanks for the advice, George

[Wunderdave]

If someone asks me for well done I might just cut them off from my dinner invite list!

[grisell]

I agree. I'm making a poll in the Chatter section by the way.