A simple statement: sous-vide circulators offer far more utility than usually granted by naysayers or novices. It is not just a means for razor-sharp temperature precision (though it excels in this department) and, despite its fanciful, always mispronounced name, is not bound to food of the same ilk. In fact, according to Chris Young, CEO of ChefSteps, makers of one of the best circulators on the market and a robust database of sous-vide-related info, one of its best uses is one of its least talked about: thawing, and cooking, out of the freezer. Why? He broke it down for us.
Microwaves Are Bad at Defrosting
When you freeze food, whatever stray water particles exist within it freeze with it. This means there is very little liquid water in frozen food. Microwaves have a frequency of 2,450 MHz, which gives them a wavelength of around 12 centimeters.
“This frequency was selected because liquid water strongly absorbs this frequency of energy, so it heats up quickly,” Young said, “but when liquid water freezes into a solid, it expands in a crystalline form that turns out to be almost entirely transparent to microwaves at this frequency.”
According to Young, this makes a microwave uniquely unfit to thaw food, as the areas where liquid water does reside in your frozen food, it will begin to cook, and everywhere else will remain relatively frozen and uncooked (this is why microwaves set to the defrost setting often turn on, off and back on multiple times — it’s trying to heat those watery areas up, let that transferred heat melt some surrounding ice, rinse-and-repeat).
It’s Way Faster
Because we now know that microwaves cannot be trusted with the defrosting or thawing frozen food, we must look for alternatives. Moving the frozen food from freezer to fridge is a thawing process that can take half a day or more (depending on the size of the frozen food), so not exactly ideal for agile dinner prep. Dropping completely frozen food into a sous-vide bath will take longer to cook than room temperature or refrigerated food, but not nearly the time it takes to thaw in the fridge.
It’s also safer (and faster) than thawing on the countertop and, because it acts as both the “thaw” and a precise, even cooking process, is superior to other methods like running under a hot sink. According to Young and ChefStep’s guide to cooking frozen food in sous-vide, the cooktime should be roughly 1.5-times the normal cooktime.
Young admits this is just a rule of thumb, though, as they work to develop a more robust mathematical model for predicting thawing range for different foods. “In many cases the time required to thaw will be significantly faster,” Young said.
There’s No Loss of Flavor
This explication, in Young’s words is “kind of complicated.” There’s ice inside and outside the cells that make up your frozen food, and there’s even some liquid water left inside as well (likely because salts or proteins have dissolved into it, lowering its freezing temperature). If you thaw food slowly — on your countertop or in your fridge — the ice inside the food melts first, and the residual water will wick onto the frozen cells on the exterior. This wicking pulls water from the food and lets it slide off and into that puddle you always find under thawed food.
This is what sets sous-vide cooking’s functionality apart — according to Young, “there’s less time for the water to be wicked out before everything thaws as the meat or seafood cooks from frozen.” Basically, it’s able to cook directly from frozen without sacrificing even cooking or the moisture of the food.