APO vs SV immersion temperature

Then you know, as do I, that each horse or bull is a new experience. I accept that, but I also know they all have four legs and some of their tricks can be learned from past experience. This isn’t something one can learn from past experience because there’s never been an oven quite like this one, so we can only accept it is as wonderful and the maker says it is until we find it isn’t. This isn’t quite as sous vide friendly as expected. I’ve learned that now so I’ll likely not use it for that. Sometimes you just have to say, no, that’s not a bull I want to deal with.

The oven will totally sous vide with ease! We’d love to help however we can. Suggest trying a standard equilibrium cook. Say, 130F/100% two hours for a 1" thick steak, and then sear. It will be perfect! The sous vide mode/program you are using is just one way the APO can sous vide, but it is not the only way.

3 Likes

Thank you

Hey Jerry, that’s precisely why i advise cooks starting with the APO that they could do better if they forget most of their experience with conventional cooking and focus on learning how to optimize cooking with their new oven. It’s that different, and that good.

1 Like

Thanks for that. I look forward to the adventure!

Thanks, I’ll clear the decks for new adventures.

Rodeo? Are you eating horsemeat? Well, I guess there is bullriding, too, at rodeos.

Also known as the Delta T method.
Using the equal Librium method, it can take hours for the core to reach the target temp.
Using a Prime Rib Roast as an example and using a 135-degree water bath it will take 6 hours for the core of the roast to hit 134 and another hour to hit 135.
Using the Delta T method you would raise the water temp by 2 or 3 degrees. That would knock up to two hours off the cooking time.
Baldwin made a cross-reference chart to give you time estimates.
Heating time from 41 degrees to 1 degree below bath temp.

Welcome @ssmith10pn

Be careful. The MathematicalChef Dr. Douglas Baldwin’s ‘SV for the Home Cook’ is written for immersion cooking SV and not for humidity / steam cooking. The enthalpies (sum of internal energy and product of pressure and temperature) are very different and complicated to determine. Note in the Table 2.2 explanatory text four mentions of ‘bath’.

The graphic relationship is in the Mollier Diagram that is so intricate that I can’t post a complete image at a readable scale. The dark line curve about through the middle, that one might be able to read SATURATION LINE is of saturated steam. Above is supersaturated steam, and below is water vapor.

I believe that we have brewers here that should have experience with the relationship.

I believe @chatnoir advice above is good advice.

My scenario was hypothetical to Explain Delta T cooking.
I’m not sure why you wanted to go down that rabbit hole.

Bingo!!

@ssmith10pn @Douglas I have a follow-up question, since we are digging into this subject. The tables on that website list the times to pasteurize poultry, starting from 41F, in a water bath. If I bring chicken to a given internal temperature, say 150F, quickly using this Delta T method (let’s say setting the oven to 160F), then I still need to hold it for some time to pasteurize. How long should that be?

“Chicken Breast 101” recipe specifies a “Hold to Pasteurize” stage, 25 minutes at 142F. Is there a way to figure this out in general? Either from Baldwin’s tables, or via some rule of thumb?

The question, of course, extends to other types of meat, with pork probably being the most pressing, and different target temperatures. This seems to be the biggest obstacle to extending an arbitrary SV recipe to this extra fast Delta T cooking. Even with the internal probe, it’s not enough to reach the target temperature, you have to hold the meat for some unknown time.

I use this as a reference.

https://douglasbaldwin.com/sous-vide.html#Table_C.2

These are amazing. Thank you! (I’m ashamed I missed Appendix C.)

Your first table has an ominous remark that “humidity must be considered”. And a possibly related criticism of steam ovens appears in Baldwin’s Appendix B; at least the warning not to use his tables for them.

On the one hand, it sounds like if we know the internal temperature from the probe, it should be enough to follow the government tables and just hold it for the given time. On the other hand, the humidity comment worries me. (It’s also the case that the “Chicken Breast 101” recipe suggests, for 142F, 25 minutes vs the 19-24 minutes in Table C.2. I assume that’s just the recipe playing it safe and rounding up. But maybe it’s related to humidity?)

It’s possible the 101 recipe is calculating for a 7 log reduction instead of a 5 log which would require a longer hold time. That’s just a guess though.