Wednesday, May 7, 2014

Induction Deconstruction

Over this past week alone, I've found myself in conversations with four different people on the topic of induction burners and why they're superior to other methods of heating.  I've taken this as a sign that either A: now would be an ideal time to introduce readers of my blog to the science and benefits of induction cooking or B: that I really need to make some new, non food-centric friends.

Since making friends takes a lot of time, AND I already have a food blog running I opted for the former.  

I started cooking with induction about 6 years ago after receiving a small, portable Viking unit as a gift. This little workhorse has since taken up permanent residence next to my once dependable, gas range and I use it almost exclusively in its place. There are a number of induction manufacturers on the market with units available in large, counter top models that replace your current stove as well as small, portable units like the one I own.

As I told my curious friends, there are several, significant advantages to induction cooking over other methods, all of them a result of the details in how an induction system works. Unlike gas or electric cooktops, which work by transferring heat from a flame or coil to the cookware via conduction, induction cooktops create heat directly within the cooking vessel itself. This difference in delivery provides significant advantages to the chef, but more about that later.  First let's understand how they do it.

When turned on, coils inside an induction burner are powered with an alternating, electric current. This current creates an electromagnetic field that rises slightly above the unit's surface. When a "conductor", such as a metal pot or pan, is placed within this electromagnetic field, it receives a very small current (about 1 volt), and in doing so, develops its own electromagnetic field. 

The cookware's own electromagnetic field now creates more, smaller electric currents called "eddy currents" within the cookware itself.  Once again, these eddy currents have their own electromagnetic field which then agitates the individual metal molecules within the cookware and finally it is this molecular agitation which creates friction, causing the cookware to heat up.

As I attempted to describe this process to my friends last week, and once again while writing this blog post, I realized just how complicated this relatively simple process can be to explain with words. The following therefor is a short video I put together to hopefully help present this concept with a little more clarity.

Okay, so now we're all on the same page of HOW induction cooking works but I bet a lot of people are still wondering WHY?

First, induction cooktops are fast.  Because they create heat within the cookware itself rather than  transferring heat to it such as a gas, or electric range would, induction cooktops are capable of bringing a pot of water to a boil or a pan to a searing heat in a fraction of the time. More importantly, the heat that is generated is uniform throughout the cookware, devoid of the hot and dead spots irritatingly common when using many traditional ranges. 

The heat produced by an induction burner is directly relative to the frequency of the molecular friction produced in the cookware.  This means that a 'High' setting on an induction range will agitate the molecules in your cookware a lot and a "Low" setting will agitate them a little.  This change is immediate and depending on the accuracy of the burner being used, can be tweaked and varied with great precision.  For this reason I prefer models with a rotary temperature dial over the ones with preset buttons.

With no open flames or glowing hot coils, induction burners are a much safer option than other types of cooktops.  As I continue the process of scouting locations for a restaurant I'm opening here in Seattle, the induction option has allowed me to consider many locations that would otherwise be off limits. Fire and safety codes stipulate that any cookware with an open flame must be placed beneath a Type I Hood, the most costly and pain-in-the-assedly type of hood known to man. 

In addition to requiring fire suppression equipment, Type I Hoods need to be in a space that can be vented directly to a roof (not practical for many buildings with residences located above) and will run you about $1500 per linear foot!  By using small, portable induction burners, I'm able bypass many of the fire and safety rules, their ridiculously high installation costs and can even consider locations that were not originally designed and built out as a restaurant.  Even though the 'kitchen police' aren't going to fine home chefs for cooking with whatever they fancy in their own house, the safety benefits of induction burners aren't lost on them either.

The only thing left to consider before scrapping your current stovetop and moving to an all induction kitchen is the cookware. Because induction burners employ electromagnets to achieve their effect, cookware must have a high ferrous, metal content at its base*; or in layman's terms, a magnet has to stick to it.  All cast iron, some grades of stainless steel, and any other metals with a high ferrous core will work.  Glass, solid copper and solid aluminum pans won't so chefs who've heavily invested in these might want to think twice.

For anyone without a $5000 copper cookware collection however, and considering a kitchen upgrade, or simply in 'need' of another awesome gadget to round out their cooking arsenal, I can't sing to the praises of induction enough. 

* I stand corrected, 2 things to consider. I just discovered a manufacturer's website which states, "regardless of your cookware's composition, induction burners will not work during a power outage" so caveat emptor. Duh