Cornflour, it’s one of those kitchen staples, but yet so many of us are not really sure what the heck to do with it. Hopefully I can help shine some light on when and why to use this illusive powder and how exactly to do so. This post is about the British naming convention of ‘cornflour’. In the US and other parts of the world, I believe the same product is called corn starch.
What is cornflour?
Cornflour is a very fine flour made from maize.
Why use cornflour?
Cornflour is a great aid to help you thicken sauces, gravies, stews, curries… basically any food that you feel is to watery and you want a thicker sauce for. It is flavourless so won’t interfere with the taste of your dish. It will, however, make the sauce go a bit ‘cloudy’ so it’s best not to use it when you have a clear sauce.
How do I use it?
I generally mix it with 1 parts flour to 1 part cold water. For most sauces, the ‘part’ I use is a tbsp and it’s more than enough. As a guideline you need around 1 tbsp of cornflour to bring 250ml of sauce to a medium thickness. The amount of water vs flour isn’t too important, the thicker the mix you make the less you’ll need to add. A lot of people will use equal parts of flour to water, or 2 parts water and 1 part flour. Just make sure that you use enough water to be able to mix it properly.
Don’t try and add the cornflour directly to your dish as it will go all lumpy and won’t be pretty!
Simply put the cornflour in a small bowl, add your tbsp of water and mix very well until you have a smooth consistency. The mixture you are making is called a ‘slurry’ if you want to be technical.
Add the mixture slowly to your dish, maybe a teaspoon or so at a time and stir well. Once added bring the dish to the boil and simmer for a few minutes. Without the heat the thickening agents won’t work. Once you add the cornflour the molecules in it start to ‘soak’ up the water, causing them to grow or expand. Conversely, you don’t want to heat the liquid for too long as this can cause the sauce to thin again (I’ll not try to attempt the science part here).
Thickening slow cooker recipes with cornflour
First time I tried to do this, I was immensely frustrated because it didn’t seem to do anything! That was when I learnt the importance of heat in the cornflour thickening equation. The slow cooker doesn’t get hot enough to heat the cornflour enough to thicken the sauce.
I find myself often feeling the need to thicken slow cooker dishes – since no liquid escapes during the slow cooking process itself. Simply follow these instructions:
- About 10 minutes before you want to serve, pour the liquid from the slowcooker into a saucepan.
- Add the cornflour as outlined above and bring to the boil. Simmer the liquid for a few minutes, stirring every now and again.
- Once the sauce has thickened, take off the heat and leave to cool slightly for a few minutes.
- Add the liquid back into the slow cooker, stir through and replace the lid for the last 5 minutes of cooking.
A bonus use!
When you mix cornflour with water it becomes this amazing substance that has the properties of both liquid and solid. Simply mix in enough water to get a ‘custard’ like consistency. When you run your fingers through it, or pour it, it acts like a liquid, but try and ‘punch’ it and it will be hard. I would say this is one for the kids, but I have to be honest, I have made some of this stuff for myself in the past, it’s quite a good stress relief to play with. Here’s the science behind it, if you want to read more.