Sous vide

[jonumberone]

Originally Posted by pnoon

So I have a couple of unrelated questions for the vets/experts here.

I always preheat the water to the desired temp. And then add my food.
I saw this pic from a website and wondered if it is advisable to put food in room temp water and bring food and water up to temp.

Peter, I always bring the water up to temp. I don't see any reason to put the food in before. I'm going with the if it isn't broke theory.
I know Adam has done some stepped temperature cooks. He might have more insight into why or why not.

One reason could be that the size of the roast coupled with the size of the container wouldn't allow for heating the water first.
If you fill up to the min line on the Anova, bring the water up to temp, then add the roast it may bring your water level above the max line, or overflow the pot.
If you fill the pot to the max line, with the roast in the pot, then take it out you might fall below the min line.
The only solution in that case would be to add the roast, fill up the pot, and press start.

Also, the photo may look as though the meat was placed in the water and then the water is being brought up to temp.
It's just as likely that the water was at temp, the meat was added, and the temperature dropped.
I know my water temp drops 4-6° when I place a decent sized steak in it. I'm cooking in a Cambro with close to 5 gallons of water in it.
In fact, my water drops a degree just from opening the lid.
That looks like a pretty big roast in a 10-12 quart stockpot.
That could've easily dropped the temp.

Originally Posted by pnoon

The other question I had was about multiple packages contacting one another. I know a rack is preferable. But could I place another package directly on top of the one shown here? Or would it be better to rotate them 90 degrees with some space in between?

Space in between is better.
I did 2 porchettas for the 4th of July holiday. They pushed the capacity limits of the Cambro.
I had them on a rack in the water, next to each other, but they were pressed up against the sides and were touching.
When I woke up in the morning the sides that were touching the walls were clearly a different color then the tops.
When I opened the lid the sides that were touching each other had the same color variation.
I rotated the roasts, and checked again later. The sides that were now touching had the same different color.
Rotated again, and then the next time I checked the roasts had shrunk enough that I was able to get some wire racks between them.
The water is what cooks the food. You want as much water as possible circulating around the food.
The whole reason for vacuum sealing is to get the water as close to the meat as possible.

I hope this helps.