Rice milk or rice drink consists primarily of water and rice, whereas vegetable oil is often added to commercial products. Depending on the manufacturer, rice milk may also contain flavoring agents, minerals, or thickening agents. Many products that are commercially available also undergo UHT (Ultra-high temperature processing, ultra-heat treatment, or ultra-pasteurization) to make it last longer. Rice drinks are a popular alternative for individuals who are lactose intolerant or want to avoid animal products. The rice plant readily absorbs arsenic via the roots, and many studies have shown that rice milk contains elevated arsenic levels.
From Wikipedia: Rice milk is a grain milk made from rice. It is mostly made from brown rice and commonly unsweetened. The sweetness in most rice milk varieties is generated by a natural enzymatic process that cleaves the carbohydrates into sugars, especially glucose, similar to the Japanese amazake. Some rice milks may nevertheless be sweetened with sugarcane syrup or other sugars.
Comparison to dairy milk:
Compared to cow's milk, rice milk contains more carbohydrates, but does not contain significant amounts of calcium or protein, and no cholesterol or lactose. Commercial brands of rice milk are often fortified with vitamins and minerals, including calcium, vitamin B12, vitamin B3, and iron. It has a glycemic index of 86±7 compared to 37±4 for skim milk and 39±3 for whole milk. Rice milk is often consumed by people who are lactose intolerant, allergic to soy or milk, or have PKU. It is also used as a dairy substitute by vegans.
Commercial brands of rice milk are available in vanilla, chocolate, and almond flavors, as well as the original unflavored form, and can be used in many recipes as an alternative to traditional cow milk.
Rice milk is made by pressing the rice through a mill using diffusion to strain out the pressed grains. It is sometimes also made at home using rice flour and brown rice protein, or by boiling brown rice with a large volume of water, blending and straining the mixture.
Some varieties contain added rice oil, salt, sugar (usually raw cane sugar), and/or flavoring (e.g., vanilla or chocolate), as well as thickening agents such as guar gum or carrageenan.
Vitamin- or mineral-enriched (especially calcium) rice milk is very common since as compared to dairy milk, it is very low in minerals. Rice milk contains very little protein and hardly any fat, and is lactose- and gluten-free.*
In Europe, rice milk is mainly used by vegans and people with a milk protein allergy or lactose intolerance. Rice milk is unsuitable for infants as a substitute for breast milk because it does not contain essential nutrients and can cause deficiency symptoms such as anemia and rickets.*
Making homemade rice milk:
Note (italics): * = Translation from a German Wikipedia entry