Looking at Douglas Baldwin's charts for time to heat a piece of meat sous vide (table 2.2), a cylinder with diameter X heats through much faster than a slab with thickness X. This makes sense to me. The change in time needed can be quite drastic when you get to a larger X, though.
However, when looking at pasteurization times for beef (table 5.1), the shape of the meat doesn't seem to be taken in to account. I don't understand why not. Surely if the meat gets to temperature faster, it must pasteurize faster as well.
From the above tables, a 50mm (thickness) steak takes 3 1/4 hours to pasteurize at 134.5F. If it's a slab, it takes 3 1/2 hours to get to 133.5F through out. If it's a cylinder, it only takes 2 hours. Do I really need that additional 1 1/4 hours for pasteurization?
Can I adjust the pasteurization times for a different shape of meat? If so, how can I calculate what that change is and how much time I really need for pasteurization?
Best Answer
It depends on what is to be pasteurized. If one aims for pasteurizing the surface only, then the shape is more or less unimportant. If however one wants to pasteurize the core, then the shape will affect the times.
To be on the safe size, measure the thickness where the meat is thickest.
Myhrwold writes in http://forums.egullet.org/index.php?/topic/116617-sous-vide-recipes-techniques-equipment-2004-2010/page_st_120_p_982720#entry982720 about cooking times (not pasteurization times):
A side note:
If you have an iPad or iPhone then I can recommend SousVideDash. One must enter meat type, shape and size, initial and final temparature. Then graphs are drawn that shows pasteurization times for both surface and core (or more precisely graphs of the reduction of salmonella and listeria).
See the website:
http://www.sousvidedash.com/