At 10 minutes to go in a 3 hour cook, the pressure suddenly dropped
and we decided that all the water had been used up. It was a good
guess but it was only later that we read in the instructions that the
pressure should have been allowed to drop slowly at it's own rate (~
15 minutes) rather than released quickly. Anybody any idea why and
whether it will have any impact on the pud ?

Rob

On 2004-11-21, Rob Graham > wrote:

> 15 minutes) rather than released quickly. Anybody any idea why and
> whether it will have any impact on the pud ?

With pressure cooking there are basically 2 ways to decrease pressure, fast
and slow. Slow is as you discribe, fast is to put the whole pressure cooker
under cold running water. The only reason I can think of for the slow way
is to minimize pressure differences between the inside and outside of the
food. A possible example might be pressure cooking whole cranberries. An
instant drop in the pressure might cause all the berries to burst. I've
never experience this phenomena and I doubt there are too many foods where
this would be an issue, but that's my guess on reason for the slow cool down
method. If your pudding came out ok, it obviously wasn't a problem.

nb

notbob > wrote in
news:B34od.369785$wV.330429@attbi_s54:

> On 2004-11-21, Rob Graham > wrote:
>
>> 15 minutes) rather than released quickly. Anybody any idea why and
>> whether it will have any impact on the pud ?
>
> With pressure cooking there are basically 2 ways to decrease pressure,
> fast and slow. Slow is as you discribe, fast is to put the whole
> pressure cooker under cold running water. The only reason I can think
> of for the slow way is to minimize pressure differences between the
> inside and outside of the food. A possible example might be pressure
> cooking whole cranberries. An instant drop in the pressure might cause
> all the berries to burst. I've never experience this phenomena and I
> doubt there are too many foods where this would be an issue, but that's
> my guess on reason for the slow cool down method. If your pudding came
> out ok, it obviously wasn't a problem.
>
> nb

You pretty much hit it on the head, notbob. The potential for abruptly
expanding from the inside out can easily result from quick pressure
release. I've even seen this difference in a roast. It may or may not
have affected the pudding, as I've not something like that in the pressure
cooker before.

--
Wayne in Phoenix

*If there's a nit to pick, some nitwit will pick it.
*A mind is a terrible thing to lose.

notbob > wrote in
news:B34od.369785$wV.330429@attbi_s54:

> On 2004-11-21, Rob Graham > wrote:
>
>> 15 minutes) rather than released quickly. Anybody any idea why and
>> whether it will have any impact on the pud ?
>
> With pressure cooking there are basically 2 ways to decrease pressure,
> fast and slow. Slow is as you discribe, fast is to put the whole
> pressure cooker under cold running water. The only reason I can think
> of for the slow way is to minimize pressure differences between the
> inside and outside of the food. A possible example might be pressure
> cooking whole cranberries. An instant drop in the pressure might cause
> all the berries to burst. I've never experience this phenomena and I
> doubt there are too many foods where this would be an issue, but that's
> my guess on reason for the slow cool down method. If your pudding came
> out ok, it obviously wasn't a problem.
>
> nb

You pretty much hit it on the head, notbob. The potential for abruptly
expanding from the inside out can easily result from quick pressure
release. I've even seen this difference in a roast. It may or may not
have affected the pudding, as I've not something like that in the pressure
cooker before.

--
Wayne in Phoenix

*If there's a nit to pick, some nitwit will pick it.
*A mind is a terrible thing to lose.

notbob > wrote in
news:B34od.369785$wV.330429@attbi_s54:

> On 2004-11-21, Rob Graham > wrote:
>
>> 15 minutes) rather than released quickly. Anybody any idea why and
>> whether it will have any impact on the pud ?
>
> With pressure cooking there are basically 2 ways to decrease pressure,
> fast and slow. Slow is as you discribe, fast is to put the whole
> pressure cooker under cold running water. The only reason I can think
> of for the slow way is to minimize pressure differences between the
> inside and outside of the food. A possible example might be pressure
> cooking whole cranberries. An instant drop in the pressure might cause
> all the berries to burst. I've never experience this phenomena and I
> doubt there are too many foods where this would be an issue, but that's
> my guess on reason for the slow cool down method. If your pudding came
> out ok, it obviously wasn't a problem.
>
> nb

You pretty much hit it on the head, notbob. The potential for abruptly
expanding from the inside out can easily result from quick pressure
release. I've even seen this difference in a roast. It may or may not
have affected the pudding, as I've not something like that in the pressure
cooker before.

--
Wayne in Phoenix

*If there's a nit to pick, some nitwit will pick it.
*A mind is a terrible thing to lose.

On 2004-11-21, Wayne Boatwright > wrote:
>
> You pretty much hit it on the head, notbob. The potential for abruptly
> expanding from the inside out can easily result from quick pressure
> release. I've even seen this difference in a roast.........

Many many years ago when I was still wet behind the ears, I operated a steam
retort in a cannery. This was definitely an issue with cans. Pumping cold
water into the retort would drop the pressure so fast, the cans would, if
not burst, at least bulge, rendering them unsellable. So, pressurized air
was pumped in along with the cold water to contain the heat generated
pressure inside the cans till they cooled. Though I've never seen an
exploded roast or anything I've home pressure cooked, I figure the priciple
is the same. If there's another reason, I'm open to enlightenment.

nb

On 2004-11-21, Wayne Boatwright > wrote:
>
> You pretty much hit it on the head, notbob. The potential for abruptly
> expanding from the inside out can easily result from quick pressure
> release. I've even seen this difference in a roast.........

Many many years ago when I was still wet behind the ears, I operated a steam
retort in a cannery. This was definitely an issue with cans. Pumping cold
water into the retort would drop the pressure so fast, the cans would, if
not burst, at least bulge, rendering them unsellable. So, pressurized air
was pumped in along with the cold water to contain the heat generated
pressure inside the cans till they cooled. Though I've never seen an
exploded roast or anything I've home pressure cooked, I figure the priciple
is the same. If there's another reason, I'm open to enlightenment.

nb