Rice

See also Brown rice syrup and syrup solids

General

Oryza sativa

Rice is in the genus Orzya and part of the grass family (Poaceae) that includes other common grains such as millet, sorghum, corn, oats, barley, rye and wheat. Unlike the latter three, rice is a naturally gluten free grain. Oryza sativa (generally known as Asian rice), was domesticated in the Yangtze valley of modern day China some 10,000 years ago before its cultivation spread to other parts of Asia and eventually Europe and the Americas. The two major subspecies of Orysa sativa are japonica (short-grain) and indica (long-grain). There is a wide variety of rice types and cultivars within these two branches that reflect the diversity of locations rice has been adapted to and specific food traditions associated with those places. Examples include Basmati, Jasmine, Arborio, and glutinous (sticky not gluten-containing) rice to name a few. Less widely grown and available (and even less associated with brewing) are Oryza glaberrima (African rice, a cousin of O. sativa) and wild rice (in the genus Zizania) that has been a food source in North America pre-dating European contact. Annual global rice production is approximately 757 million metric tonnes, making it third in the list of global cereal production -- nearly equal to wheat (see graph).

Source: Food and Agriculture Organization of the United Nations

Rice in Brewing

Rice in the Asian brewing tradition

Originating in Asia, it's no surprise that rice, a grain rich in starch, would factor into a number of fermented alcoholic beverages across the continent. Although often described in English as "rice wines", it would be more accurate to categorize these beverages as "beer" (a fermented drink made from the starches of plant material). In China, analysis of 9,000 year old pottery vessels has provided evidence of rice as a fermentable for beer dating back long before beer was being brewed from barley and other grains in Mesopotamia. Huangjiu (a beverage traditionally made from fermented rice and/or millet) has a long history in China, with written references going back to the first millennium BCE. It remains a popular drink with 3.53 million kilolitres (35 million HL) being produced in 2019 -- roughly equivalent to the UK's annual (barley) beer production. Sake, made from polished rice and koji molds (responsible for breaking starches down into fermentable sugars) is thought to have been an established beverage in Japan by the 2nd or 3rd century BCE. By the 7th century CE, a guild of sake brewers had been created to service the imperial court and in the 10th century sake production had been documented in a code of practice. Japanese sake production was roughly .5 million kiloliters in 2018, down from 1.7 million kiloliters in 1975. Other fermented rice drinks are firmly rooted in both traditional and modern day practices in a number of other cultures throughout Asia including in Malaysia (Tuak), Nepal and Tibet (Chhaang), and Korea (Baekse-ju). The likelihood is that most of these beverages were made from un-malted (and non-kilned or roasted) grains, making them somewhat different than beers in the European brewing tradition -- and perhaps partly to explain why they are frequently described as "rice wines" by western audiences.

History within European brewing tradition

Advertisement for Gillman and Spencer's "Rice Malt" in H. Stopes "Malt and Malting" (1885)

The use of rice in the European brewing tradition is relatively recent (primarily since the mid-19th century) and almost exclusively as an "adjunct" to barley -- i.e. as an unmalted supplement to the main malted barley grain bill. Often associated with American macro lagers, the use of rice as a brewing adjunct actually came about in German-speaking Europe during the 1860s, one or two decades before being adopted by American brewers.

German-speaking Europe

Prior to 1906, the infamous Reinheitsgebot brewing purity law (banning the use of fermentables other than barley malt) applied only to Bavaria -- a southern region of German-speaking central Europe. (The word "Reinheitsgebot" was in fact only applied in 1916). In other German states there was no such ban on barley malt substitutes, and Brausteuergebiete (North German Brewing Union) brewing taxation records indicate that rice was the most popular adjunct through the end of the 19th century. Though never a significant portion of the grain bill in German brewing, the use of rice adjuncts peaked in 1898. That usage fell to essentially nil after 1906 when a German parliamentary (Reichstag) taxation ruling applied the Bavarian barley-only stipulation across the then German Empire (Deutsche Reich).

United Kingdom

In the UK, the 1880 Free Mash-Tun Act (aka the Inland Revenue Act) opened up new avenues for brewing with non-barley grains. Perhaps inspired by brewing developments in central Europe in the last decades of the 19th century, rice, maize (corn), oats and other adjuncts began appearing in the British brewing landscape. An 1885 guide to malt and malting by H. Stopes ("An Historical, Scientific and Practical Treatie on What Malt Is, And How To Make It") includes a section on rice, noting its warm weather cultivation meant that growing was "chiefly confined to Lombardy" (northern Italy). As an imported product, Stopes suggested that the "rough treatment" it receives in transit damages the husk making it "incapable of being made into malt by the common process of germination". The "gelatinised malt" products he refers to -- "invented in 1880 by Messrs. Gillman and Spencer since the abolition of the Malt tax)" is not malt in the current (21st century) sense. Whether made from rice, maize, wheat, barley or rye "gelatinised malt" is essentially a pre-gelatinized adjunct made using steam at high temperatures and pressure. This then-novel approach to producing adjuncts provided more readily accessible starch (in combination with enzyme intact barley malt) than what was previously available to brewers. The gelatinized rice patent owners Gillman and Spencer looked to solidify interest in their product by hosting a London Brewers' Exhibition in 1888 which awarded medals to breweries entering beers with at least 15% of gelatinised rice "malt" or torrefied barley (a similar, pre-gelatinized product). In spite of greater extract yields, rice was less popular than maize (corn) as an adjunct through the early 20th century, owing to its higher price point. For a short period of time in 1940 (due to wartime constraints on barley malt access), flaked rice saw a usage boost (but again second to maize).

United States

Late 19th century interest in unmalted adjuncts, including rice and maize (corn), seems to have been tied to lager brewing and German immigrant brewers.

Rice in California.

Varieties (species) used in brewing

Calrose is reportedly the variety of rice used by Eckert Malting -- the primary gluten free rice maltster in North America. Calrose is a medium grain, japonica sushi rice with a relatively higher amylopectin starch ratio.

Malting

In North America, there is one commercial operation producing malted rice: Eckert Malting in Brewing in Chico, California. Jim Eckert is a former University of California research associate who worked at the California Rice Experiment Station

Brewing Properties

Property	Estimate / Range	Sources
Protein	% dry matter
Beta Glucan	% dry matter
Extract Potential Malted	PPG
Starch	Amylose: %, Amylopectin: %
Gelatinization: Range	F, C
	F, C	Briggs
	F, C
Gelatinization: Onset	F, C
Gelatinization: Peak	F, C
Diastatic Power Malted	Litner
Diastatic Power Unmalted	Nil
FAN / Amino Acids
	mg/L
	mg/L
	mg/L

Gelatinization

Heat and water in tandem help break down the bonds of starch molecules, essentially unraveling them so that they are more accessible to enzymes for conversion to sugar. The temperature range for gelatinization can vary by millet variety, growing region and conditions, and malting process.[3] The temperature range cited by a number of gluten-free brewing resources is significantly higher than that of barley and wheat, leading to additional impacts for enzyme denaturing and mash schedule recommendations. Endogenous amylase enzymes denature above x• C and therefore many gluten-free brewers combine a high temperature gelatinization mash step followed by the addition of exogenous enzymes (including some that are active at these higher temperatures).

Author	Range (C)	Range (F)
Briggs	61 - 82	142 - 180
Novozymes	68 - 84	154 - 183

Proteins and diastatic power

Diastatic power is a measure of the relative strength of starch reducing enzymes in a malted grain (measured in degrees lintner).

Rice malt has a lower diastatic power than malted barley. Eckert pale malt is listed as having a maximum range of 20-35 lintner, and an average range of 20-25 lintner by Gluten Free Home Brewing.. By way of comparison, American 2-row and 6-row barley pale malt can be 110 to 160 degrees lintner.

Flavor characteristics and off-flavors

Beers with a high proportion (70%+) of rice may exhibit a wintergreen or celery seed flavor. Jason Yerger believes a remedy for this potential off-flavor is full starch conversion during mash. He recommends pre-cooking rice to gelatinize before using pullulanase (e.g. Ondea Pro), followed by alpha-amylase and potentially glucoamylase.

Zero Tolerance Discussion Threads

Academic paper - Development of an All Rice Beer (Mayer et al). https://www.facebook.com/groups/ZeroToleranceGF/permalink/545295209358043/ Malting rice. https://www.facebook.com/groups/ZeroToleranceGF/permalink/545294832691414/