Disappearing pink???

[Guest]

My buddy and I smoked our first standing rib roast this afternoon (7.8 pounds, Montreal Steak seasoning). We used two probes to keep tabs on the temps and pulled the roast when one of the temps reached about 129 or so. It cooked quite a bit faster than we had anticipated, so we wrapped it in foil and held it in a cooler for about an hour.

When we first carved the roast, each slice had some pink in it, with the middle slices being close to medium rare. As we started serving, nearly all the pink had disappeared except for the center pieces.

What would cause the pink to disappear? I'm sure there is some easy answer that I should know, but I'm perplexed. Was it just the juices coloring the meat? Was it a reaction to the air? Did the steam that was coming from the cut pieces cook the meat slightly? All these questions!!!

 

[Bob H.]

When you wrapped your roast in the foil, it held the heat in and kept on cooking just a little more. That is where the pink went. It would have probably still been pink if you had served it about 45 minutes earlier.

 

[Chris]

I would try it again but aim a little higher and don't foil it.

I like to cook to an internal of 135, but if the wife sees this, that is a 145 minimum.

 

[Guest]

Bob....the pink was there when we first carved it after taking it out of the foil. That's what is throwing me. If we had cut it before we foiled it for the hour, I can understand how the build up of heat continued to cook the meat. I can't figure out why it changed color after the foil and after the carving.

And....pink or no pink, it was still pretty good.

 

[K Kruger]

Your first suspicions, coupled with the continued cooking by the long rest as Bob notes, are likely the cause.

In the absence of oxygen red meat is purple. Cut into a raw hunk of meat or a rare steak quickly and you'll see the color change from purple to red--it is quick though. There are several factors (salt concentration, temp, Ph) that affect myoglobin (the protein that is the main pigment), and if any of the factors is high enough to affect the statability of the structure of the myoglobin then it is likely to lose an electron and turn brown.

Continued gentle cooking due to the long rest was enough to set the stage but did not go far enough to brown the meat so that when it was first cut it was brown. Migrating juices helped supply color as well, but when the the roast was cut the influx of oxygen sealed the deal. The least-cooked center retained much of its color because it was least affected by the prolonged rest.