This is good advice too.
Koshihikari is the default variety.
Learn how to properly remove the excess starch from it before you cook.
In Japan, you don't "wash" rice, you "sharpen" it.
The idea is not to remove impurities from grain but to get rid of the starchy layer that wraps it. It is easy to do and takes only 3 minutes. This is how I was taught and have always done:
1) pour rice in a big bowl (ideally the pan or the jar you'll cook it in).
2) quickly wash it with cold water: pour water, quickly give a few energetic turns to the rice, and quickly drain it. Do it twice.
3) once you've drained your rice the second time, put the bowl in front of you, take a fistful of rice in both of your hands and
gently rub one against another. Repeat about 10 times.
4) give the bowl a 1/4 turn. Repeat step 3. Then repeat step 4, then step 3 again, then step 4.
5) rince (the water should be very white and full of starch). Rince again. And again.
6) repeat steps 3 and 4. Then step 5.
7) repeat step 6. By this time, you should have done about 90~100 rubbings, and the starch has visibly been removed. Rince a couple of times until the water comes almost completely transparent.
8) add the adequate quantity of water (if you're using a jar, there should be appropriate graduations written directly onto the bowl; otherwise the rule of thumb is about 1.2 portions of water for 1 portion of rice). Preferably use soft water (low on magnesium and calcium which can alter the taste).
9) let the rice absorb water for 30~60 minutes (the longer the better) - you can, however, reach acceptable results without leaving it at all.
That's it.
In 3 minutes, you should be done with the "sharpening" (i.e steps 1~7).
If you leave too much starch, your rice will bubble a lot (it can be a mess) and taste like shit. If you clean it properly, it'll taste delicious.
Don't be too harsh when you rub the rice otherwise you'll damage it.
