Buthering

[Koyote]

I'm guessing your are talking about ~8 week old cornish cross?
Not sure what kind of bird the OP is talking about either.
I only do layer breeds and believe me they are about inedible if not rested, especially if over about 16 weeks old.

I've only done 1 batch of 9 1/2 week old Cornish Crosses. The other batches have been red rangers, barred rocks, Bresse (x2) and other random breeds anywhere from 12 to 18 weeks old. I haven't noticed any stringy or toughness. Does keeping them in a fridge for a while make them more tender? How long do you keep them cooled like that?

 

[aart]

Does keeping them in a fridge for a while make them more tender?
How long do you keep them cooled like that?

Yes, it does, IMO.
The older the bird, the longer I rest the carcass.
I go 2-3 days for the 14-16wo cockerels and 4-5 days for the 30mo hens.

 

[Ridgerunner]

Does keeping them in a fridge for a while make them more tender?

Aging is to counter rigor mortis. You let them rest until rigor passes or they can possibly be tough. That's the why of aging, to counter rigor mortis. You need to age them until the joints are no longer stiff.

Of course nothing to do with chickens is that simple. If you cook them before rigor sets up rigor mortis does not set up. Obvious when you think about it. How you cook them can affect how tough or stringy they are. As cockerels go through puberty their hormones can cause toughness, affects flavor as well. Some cockerels hit puberty much earlier than others, it;s not just an age thing. If you marinade them, the marinade can break down tissue and make them less stringy or tough. If you marinade them too long in a strong marinade they can get mushy.

Not everyone ages. If you are OK with your results, life is good. But if you ever get one that is really tough, there is a good chance that's because rigor mortis set up.

 

[aart]

If you cook them before rigor sets up rigor mortis does not set up.

I've found rigor to set in very quickly,
by the time I eviscerate(10-15 mins after killing) legs are stiff...
...I wonder if scalding for plucking speeds it?

 

[Phunktacular]

When I do Cornish Crosses, I do many birds at once. This year was about 90-95 birds. I have some plastic, food grade, 55 gal barrels. I fill them with ice and water and then place birds in them as I process them. As long as the entire bird is submerged and the water remains below 40 degrees F, they're good for a day or 2 to rest. You can dump some salt into the water for more of a brine but, I don't usually. It makes a big difference when eating a bird that was rested compared to one that has not.

 

[Phunktacular]

When I do Cornish Crosses, I do many birds at once. This year was about 90-95 birds. I have some plastic, food grade, 55 gal barrels. I fill them with ice and water and then place birds in them as I process them. As long as the entire bird is submerged and the water remains below 40 degrees F, they're good for a day or 2 to rest. You can dump some salt into the water for more of a brine but, I don't usually. It makes a big difference when eating a bird that was rested compared to one that has not.