Need help with new pressure cooker (stew meat not tender)
I got a new electric pressure cooker (Wolfgang Puck Bistro 7qt). I made beef stew in it last night. I browned the meat before cooking (all following the recipe in the book), but the meat was not tender as if I had used a slow cooker or even done it in a pot on the stove top. If fact, the meat was a bit tough.
Do I need to cook it longer or less long, or is there something else I need to do? The veggies were fine and the meat was from a package I'd used before that worked well in a slow cooker. I am at 8500' so maybe I need to slightly increase the cooking time, I don't know for sure. Since this is my first attempt at anything in the pressure cooker with meat, I'd appreciate any ideas.
Timing may be part of the problem. Vegetables (like potatoes and onions) respond more quickly to the higher heat of a pressure cooker.
With meat there are two issues - breaking down the collagen that binds meat fibers together, and tenderizing the fibers themselves. The higher heat of the pressure cooker does a great job with the collagen. But it can actually toughen the fibers themselves. One prolific PC cookbook author ( L Sass) claims that using a slow (natural) pressure release helps the fibers relax after cooking.
You didn't mention the pressure release method or time or recipe. However the the time might not have told us much, since electric pressure cookers don't necessarily use the 15psi that stove top units usually use, and your altitude alters the cooking temperatures (even under pressure).
Is this a 10psi cooker? Or is there anything in the manual that tells you that or not? One blog article on hacking an electric PC found that the cooker was actually controlling the temperature, not the pressure. While stove top PCs regulate pressure with a weight or spring, it is easier to use a temperature sensor than a pressure sensor with an electrical controls.
Sorry for resurrecting an old thread, but for anyone else who finds this thread, I have the answer. There are actually two separate issues here.
Most recipes are written for standardized pressure cookers (15 PSI - pounds per square inch) but most electric pressure cookers don't reach that pressure. I googled it, and the model above reaches 12 PSI, which means the temperature reached is less than the 250 degrees the recipe was written for.
The second issue is your altitude. The absolute pressure reached in a pressure cooker depends not only on the maximum setting (12 PSI in this case), but the atmospheric pressure as well. Anything 3,000 feet and above is considered high altitude. For most recipes, which have brief cooking times, that won't make much of a difference, but when you're dealing with a 30 minute stew, and such a high altitude, the recipe must be adjusted.
For every 1,000 feet above 2,000 feet altitude, adjust the cooking time up 5%. So if we round you up to 9,000 feet (that'll help adjust for the 12 PSI, too) you'd calculate .35 x 30 minutes = 10.5 minutes. So you'd need to adjust your cooking time up 10 or 11 minutes to compensate for high altitude. (And maybe another minute or two to compensate for having a 12 PSI PC rather than a 15 PSI).
But it gets more complicated than that. From what I've read, electric PCs actually regulate the temperature, not the pressure. In the examples I've seen the target is 240F, which corresponds to 12psi at sea level. At 8000' it might still be cooking at 240, but with a higher psi (due to lower psi outside).
The OP mentions using a recipe from the book, presumably the one that came with the cooker. That should have taken into account the different target temperature.
(sorry for repeating myself)
I think you and I may have seen some of the same stuff on the internet, but we interpreted them differently. Since its far easier (and therefore cheaper) for the pressure cooker to measure temperature, rather than pressure, that's actually what they measure.
But reaching those higher temperatures is predicated on the ability of the machine to reach higher pressures, and the maximum pressure that can be reached is cumulative, based on the capacity of the machine and the atmospheric pressure. If the machine could keep raising the pressure to match the temperate its supposed to reach, you could theoretically take one up to the heights of Mt. Everest and if it were merely a function of the EPC measuring the temperature its supposed to reach, it would do so, and the fail safe measures wouldn't be triggered, despite massively greater pressure.
But I seriously doubt such a machine would function that way. You'd have to have an absolute pressure of 26.7 (14.7 atmospheric pressure plus 12 PSI from the PC) to reach 240 degrees (more or less, my calculator says 244 degrees), so if you go up to 8,000 feet, the atmospheric pressure drops down to 10.9 PSI, which to meet the same temperature, the machine would now have to increase internal pressure to 15.8 PSI, at 10,000 feet, it'd have to go up to 16.6 PSI, at 15,000 feet, it'd have to go to 18.41 PSI. If the machine is designed to go to 12 PSI, it's going to trigger the fail safe mechanisms long before it reaches 15.8, much less higher numbers.
As for what recipe the OP used, you're right, I had automatically assumed it was from a cookbook, but it may well have been included with the pressure cooker, in which case, yes, it should have compensated for the lower psi, but neglected to address the altitude question.