When my eldest brother got married, they received a vacuum cooker (or Thermal Cooker) as a wedding gift. Ever since then, our family got hooked and now my parents, both my brothers and I each have one at home.
A vacuum cooker does what a slow cooker or pressure cooker does. The difference are:
- Vacuum cooker cooks food inside the pot that is placed inside a vacuum flask (the outer container). The vacuum flask keeps heat loss to the minimum, hence allowing the food in the inner pot to continuously cook at a cooking temperature.
- Because of this, you use the minimum amount of gas and no electricity for the cooking (except light and extractor fan, etc of course)
- The down side is that it requires reboiling once the temperature has dropped below the cooking temperature. (More about this to follow)
- Pressure cooker traps air and liquid inside the cooker. Pressure increases inside the pot, causing the boiling point of liquid increase (ie, takes longer to boil), allowing the liquid to rise to a higher temperature before boiling. During this time, the saturated steam trapped inside cookes the food.
- The down side of a pressure cooker is that if you don't use it properly, it can cause explosion. (Perhaps the newer models has increased the safety, but I have heard too many stories for me to want to try this)
- Slow cooker allows unattended cooking for many hours, but it requires constant electricity use.
I have a slow cooker at home as well, but because I took favorism since ages ago over a vacuum cooker, I have never used my slow cooker (my mum did). And since I am a stay at home mum, I don't really have a need for unattended cooking.
If I want to cook Cantonese style congee (3 hours), I use my 'wise' Rice Cooker (rice cooker that has a built-in microprocessor to provide different functions including cake baking, congee and porridge making). For soup and stews, I use our most trusted vacuum cooker.
It's very easy to cook with a vacuum cooker:
1. Heat up the soup or stew in the pot according to your recipe (you can brown meat and seasonings in it), then instead of stewing the food, place the pot inside the vacuum flask.
2. Cover it for 10-15 minutes to heat the flask up.
3. Reboil the pot, then place the pot inside the vacuum flask for 30 minutes. Or longer if you are doing something, it really isn't that fussy.
4. Reboil, which should only take 1-2 minutes, then this time you can place the pot in the flask for longer, around 50 minutes.
5. Again, reboil, this time it should only take seconds as it is still very hot inside. Then place the pot in the flask for the last time for at least 30 minutes until you are ready to serve.
6. Do check whether you are happy with your stew or soup. If not, reboil and place in the flask again when you can be bothered.
I know some of you don't favour the fact that you have to constantly reboil the food. But as I said, the vacuum cooker isn't that fussy. A lot of times after my alarm set off (30 minutes), I continued with what I was doing before I attended to it, and it still reboiled very fast.
It only requires reboiling for about 3 - 4 times, and that is the only time you are using gas. It is a very 'green' cooker comparing to any other method (except pressure cooker, but I rather not keep something that dangerous in my house)
Anyway. After much hard selling, here is a recipe for one of my favourite Cantonese Soup - Pork Ribs with Carrots and Green Mooli Soup.
3-4 Dried Scallops (Chinese Supermarket)
1 large/ 2 small Dried Honey Dates (Chinese Supermarket)
1 rack Pork Ribs
1 large Carrot, chopped
1 large Green Mooli, chopped (Chinese Supermarket) or White Mooli if you can't find any
1. Place all the ingredients in a big pot, and fill the pot up with water to cover most of the ingredients
2. Bring to boil, then simmer the soup for about 3 hours until the meat falls off the bones.
3. Season with salt and skim off as much floating oil as you can, using a spoon (try not to discard too much soup while doing this)
4. Eat with plain boiled rice and if you can find it, Maggi Seasoning Liquid for the ribs (some supermarket do them). Or serve the soup as a starter.
White Mooli can be bitter if the skin isn't shaved off properly. So I normally shave 2 layers at least off
You can replace most of the ingredients, while the dried scallop and dried honey date flavours the soup. So you can easily make chicken with carrot and potato soup, or chicken with onion and tomato soup.