Do I need to do anything special to prep a flat iron steak for an overnight SV bath?
I have seen some references to dunking in boiling water for anti microbial effect, but am not sure what the best practice is?
I am getting my meat from a cert reputable local butcher, if that matters?
Thanks!
Nope. Haha :)
Brining will give you a softer texture. I have brined duck for varying times (depending on how much of a rush I was in) and brining really does help with the texture.
You can sear it beforehand, some Maillard reaction will help in flavour development, but when I cook sous vide for more than 8 hours, I don't bother: the meat will go green/grey, which means I need to sear afterwards anyway. So I usually just sear at the end.
If your meat doesn't have that much fat, or anything to keep it moist, it can go dry. Adding some butter, or maybe rendered Wagyu fat in the case of your steak, might help.
As for bacteria, the longer you cook sous vide, the more you kill off the nasties.
It so happens that Douglas Baldwin has a short bit about flat iron steak: http://www.douglasbaldwin.com/sous-vide.html#Beef
Hope that helps :)
Many prefer a pre-sear, low temp cook, post sear...and some pre-sear from frozen. A few folks (Dave Arnold in particular) have done taste tests and prefer the flavor from the pre.. then post sear. I find that the pre-sear (or a dunk in boiling water) is necessary with something like oxtail and short rib for the purpose of disposing of surface bacteria that will multiply and off-gas in the bag when using low temperatures. This fill the bag with air and cause it to float, impacting the effect of the low temp water bath. It also produces a nasty smell when you open the bag. A good, deep sear takes care of this and begins flavor development.
