How can this give consistent results? The ratio of water to rice will be different depending on the pot size and the quantity of rice. If it’s assuming “the right size of pot” you need to specify how deep the rice is as well.
2 cups water to 1 cup rice seems a lot easier and more flexible. To cook a bit more rice, use a bigger cup.
The fixed ratio doesn't scale all that well, because some of the water is absorbed by the rice and some just evaporates. Even with a lid on water still evaporates. The evaporation portion depends on the type of pot, how long you cook and how much heat you put in.
So, if you only vary amount of rice, you really need some_factor * amount_of_rice + constant_amount and the knuckle rule has that characteristic.
I'm surprised that there would be significant evaporation loss in a pot with a close-fitting lid for 20 minutes on low heat. If you heated the water on its own I wouldn't expect a large amount to boil off... Although now I say that, I'm not so sure, maybe I should run that experiment.
I would have guessed the imprecision of 'knuckle depth' being uncalibrated with the volume of rice and the size of the pot would be greater than the imprecision of a pure volume ratio due to evaporation, but I can see that the knuckle depth thing might make sense if you're always cooking roughly the same amount of rice in roughly the same size of pot.
I've had good success cooking rice by the 2:1 ratio in both large and small amounts in various pots, so I'm still happy to vouch for that method.
Another aspect is that there is a large span in the amount of water you can let the rice absorb. A 1:1 ratio of water to rice (not accounting for evaporation) is all you need to cook rice no matter if it's short grain or long grain, but a lot of rice will also happily absorb more, like 2x its weight, if you give it enough water and time.
It sounds like you are using long grain rice given the large cooking time and high water ratio.
I have also had great success with this method ever since first being told about it. Didn't believe it could be that easy until I was shown for the first time, and sure'nuff it seems to work pretty nearly perfect every single time.
I think most people using this rule are using a standard rice cooker and they are all roughly the same size. The measurement is from where the rice is, not the bottom of the pot. In terms of the ratio, we use equal parts water and rice, plus one additional cup of water.
In terms of the ratio, we use equal parts water and rice, plus one additional cup of water.
If you're cooking about a cup of rice (which is a nice big amount with a standard measuring cup -- hard to imagine needing more unless you're cooking for 5+ people) that comes out the same as my 2:1 ratio.
Does that work if you're making a smaller amount, like a quarter or half cup of rice? Seems like it would be too much water.
After thinking about this quite a bit, I've realized that the extra water is just to take care of evaporation, and most rice will cook at a 1:1 ratio with water. Basmati rice doesn't. But Indian people don't use basmati rice for daily cooking.
It depends on the rice. 2 cups of water is good for 1 cup of rice for 1 or 2 cups of rice. If you use 4 or more cups, you'll get something soggy.
Probably the correct ratio is 1.5 when using 4 cups.
That is a much higher ratio than I am used to - 1.2:1 for sushi rice, 1.25:1 for jasmine, 1.5:1 for basmati. What kind of rice are you cooking?
On the other hand, sometimes I get lazy and cook rice like pasta, which works fine. Arbitrary amount of salted water - 5:1 or whatever - then just boil it, 'til it feels like it has the right texture, and strain it.
Basmati. But my technique is probably heathen. I use 2:1 and then cook it uncovered in a microwave (1.5 cups of rice, 20 minutes). I love the resulting texture but it might not be for everyone. I like my rice drier and more “al dente”.
2 cups water to 1 cup rice seems a lot easier and more flexible. To cook a bit more rice, use a bigger cup.