I was looking high and low on the internet for a good recipe for making my own tau sar (豆沙) or red bean paste. Thought of doing a couple of things with tau sar, such as tau sar bao, mochi with red bean fillings and rice dumplings (tangyuan). Nowadays, even for simple things such as red bean paste, kaya, or char siew, I have to roll up my sleeves and make my own. It is kind of tedious to have to always make your own stuffs even for the simplest things which I used to be able to buy easily in Singapore. But then again, I have to remind myself constantly that I am no longer living in Singapore. Now that we live so far away from "civilization", in a small belgian village far away from big cities, it's good to know how to make your own food so that you know what goes inside and in the event of famine, you won't starve to death. Haha, what Ah-Q mentality that I have. :)
Anyway, after browsing and analysing some internet recipes for making red bean paste, I came to the conclusion that for every 1 cup of red beans, I must use at least 3 cups of water for cooking and the general rule of thumb is to soak the red beans for at least 3 hours or more, the longer the better. After soaking and cooking, the red bean mixture has to be grinded in a food-mixer or grinder into a paste. You then have to add either white sugar or rock sugar, either during boiling or during grinding. There are also some which require frying the red bean paste in a non-stick pan with some peanut oil as a final step, and adding the sugar then. So much advice I have gleaned from just a couple of minutes of searching on the internet. The power of internet cannot be underestimated, really. :)
So for my little experiment, I used 400g of red beans (or haricot rouge in French).
First, I put the red beans in a big pot and covered them with enough water to soak through the night. By the next day, the water was almost soaked dry by the beans, then I added more water to soak them further. After soaking, I drained the beans and put them in a big cooking pot with 1.2 litres of water (proportion of 1 to 3) and cook them at high heat. Let the red beans come to a boil, and when they start foaming, quickly lower the heat to medium-low. Then cover partially with a lid, allowing a small hole for the steam to escape and let the beans simmer for at least 1.5 hrs or until they are soft and broken, meaning that they can be squashed easily with your fingers. At any point in time, you can always top up with some water to ensure that the red beans are always covered well in water.
After that, drain the red beans and allow them to cool for a while, before placing them in a food-mixer or grinder. (Some people prefer to sieve the red beans through a sieve to remove all the bean husks before grinding. I didn't do this step so you can see in my photos that my red bean paste is not as smooth.) If your grinder is too small, you can do what I did, which is to divide the softened beans into 3 portions and grind them one portion at a time. In that case, I also made sure that I divided the sugar into 3 portions to maintain the same level of sweetness.
For the amount of sugar to be added, initially I wanted to use an amount of sugar which is half that of the red beans, but later I decided to be more health conscious and hence I reduced to 150g sugar for 400g of red beans. I find that this is about the right level of sweetness for me.
I skipped the step of frying the red bean paste in a non-stick pan. Although some recipes require the adding of sugar during frying but as I already added my sugar during grinding, I find that there is really no need to have an additional step of frying. Well, it depends on your requirements really. If you want your paste to be more fragrant and moist, then it makes sense to fry it with some peanut oil.
I actually measured the weight of my final finished product and I found that I managed to produce 880g of red bean paste from 400g of red beans and 150g of sugar. Not too bad a result. Then I rolled the red bean paste into small balls of 40g each and put them in ziploc bags to be freezed. Just nice, 22 red bean balls of 40g each, waiting to be made into tau sar bao and red bean mochi or maybe even red bean rice dumplings (tangyuan). :)
My recipe is inspired and adapted from this very informative step-by-step tutorial.