Rice milk is one of the most popular grain milks, often used as an alternative to dairy milks, to soy milk, or to various nut milks. Along with oat milk, it is one of two grain milks widely found in the West, although rye milk, spelt milk, wheat milk, and quinoa milk are all also found in packaged form. Because rice milk uses such an affordable ingredient, rice, and because it is relatively simple to make, home-made rice milk has become quite popular among those interested in a cheap alternative to dairy or other non-dairy milks.
Most typically, rice milk is made from brown rice, and is naturally sweetened by an enzymatic process that generates a fair amount of glucose. Some rice milk is nonetheless sweetened, usually by the addition of a sweetener like sugarcane syrup, or sometimes agave or honey. Packaged rice milk is often also found in other flavors, generally with either vanilla or cacao added to give the appropriate flavor, and this may be done at home when making rice milk as well.
To make rice milk from scratch, one needs only rice, water, and either cheesecloth or a blender. Some people use very little water with their rice, while others use a great deal of water, and it is up to each individual to experiment to find the level that is best for them. Similarly, one can either squeeze the rice milk out of the rice, using something like cheesecloth, or simply blend the rice and water in a blender to make a puree that acts as rice milk.
Generally, one uses about 4C (1L) of water for 1C (250mL) of rice. Some people recommend substantially more water for the rice, up to four times as much, which of course results in a more watery rice milk. Different varieties of rice will also yield different flavors and strengths, and so water amounts may need to be shifted to best match the rice used.
The simplest way to make rice milk is simply to add the boiling water to the rice, letting it simmer for an hour or so. Once it has been cooked, the entire mixture can be dumped in a food processor or blender, and pureed until it is completely smooth. If flavoring is desired, it is added at this point, as is additional sweetener. All in all, this method takes just about an hour, and can be scaled to almost any size to make large quantities of rice milk.
The other way to make rice milk is to rinse the rice until it is clean, then to pour boiling water over it, and let it sit for an hour or two. About a fourth of that soaked rice can then be taken out of the water, and added with fresh water in a blender, and blended into a rough texture. This rough blend is then added back to the original rice, where it is brought to a simmer for half an hour or so. The entire mixture is then placed in cheesecloth, and the liquid is squeezed out, rendering a slightly different texture and strength of rice milk than the simpler method.