Soy sauce, a key element in almost every Asian cuisine, is unarguably a must-have ingredient and condiment for every kitchen, but it's not always the easiest thing to cook with.

Those who have used soy in the past will know that you can easily ruin a meal if you even slightly overdo it. Just a few drops more than you need can turn a delicately seasoned dish into a salty, bitter, brown mess...trust me I know! Our advice here at School of Wok is to take it easy when cooking with it, it's better to put in too little than too much, you can always add a bit more later on.

You don't need to have the most refined palate to realise when you've been a bit too liberal with the stuff, leaving you with squinted eyes and your tongue sticking out (you know the face I mean).

Soy sauce is essentially made from soy beans, wheat (in most cases), salt and water and is then leftsoya-bean to ferment for anything from a few weeks to over a year before being pressed to leave a rich liquid. During the brewing time, the mixture takes on a strong, complex, salty flavour, which means that when using it as an ingredient in cooking, a little goes a long way!

While soy is often categorised as being either ‘dark' or ‘light', there are in fact several different varieties and grades so it is important to know which one (and how much) to use, as SOW head chef, founder and self-confessed ‘soy sauce connoisseur' Jez told me. "Quantities are very important," Jez said. "All the soys are made from fermented soya beans and have a certain amount of salt or sugar content...You need to know when to stop otherwise you could very easily overpower your dish with soy sauce."

"Try the different brands for yourself to see," Jez recommends. "You should be able to easily tell the difference between dark and light soys, with the dark being more viscous than the light. When it comes to cooking with soy sauce just remember the general rule of thumb: ‘light' is for seasoning and marinades, while ‘dark' or sweet soy is more for colour and texture - great for sweet sticky things like BBQ roast pork or soy sauce chicken."

Jez said he tries to stay clear of things with MSG but admitted that "it is hard to find authentic Chinese products without it sometimes".

In my opinion, finding my favourite dark soy has been a lot tougher than finding a good light soy. I have struggled for years to fine-tune the perfect fried rice dish and think it has come down to my choice of dark soy...often the cheapest one available when I was a student. Generally, the cheaper soys are chemically made (by ‘chemical-hydrolyzation') and are produced a lot quicker than the brewed types, meaning that sugars, colours and flavours developed in the fermentation process have to be artificially added - this often leads to cloudier, bitter and unpleasant soys.img_0473

Alas, I have resorted to stealing my Dad's dark soy sauce (which he evidently keeps in bulk in the garage) every time I visit home. A few years' ago he siphoned some into an empty bottle for me and has been my sole supplier of dark soy ever since. It's a rich, sweet, caramel-tasting soy that works well with so many Chinese dishes, but particularly fried rice. This reminds me, I'm running a bit low...think a trip home is needed - I should really find out which brand he uses some day.

Anyway, if you're a bit unsure about how to use soy in your own Asian dishes, or are looking for a few tips or tasty recipes, why not book yourself into one of our cookery classes at SOW when our Convent Garden headquarters open next month. Click here for more details.

For some inspiration, watch the video below to see Jez in action, whipping up the quickest vegetable chow mein known to man.