Beer is a fermented beverage made from the starches of plant material. It is common (though more restrictive) to think of grain (usually malted) as the primary source of that starch material. Cereal grains are the dried fruit (caryopses) of the grass family, Poaceae (which includes gluten free grains such as millet, sorghum, corn and rice, as well as gluten containing grains like barley, wheat, and rye).
Pseudo cereal grains resemble caryopses, but come from plants outside of the grass family. These include amaranth, buckwheat, chia, and quinoa (all of them gluten-free, starchy pseudo cereal grains).
See also List of Commercial Gluten Free Malts
Composition comparison of fermentables
|Name||Starch (g)||Amylose %||Amylopection %||Protein||FAN mg/L||Zinc|
|Proso Millet||28||72||150 - 365|
|Med Grain California Rice||17||83|
|Buckwheat malt||150 - 275|
Cereals and Pseudo Cereals
See main article Millet
Millet is a major source of fermentable material for gluten free craft- and homebrewed beer providing similar flavor profiles to malted barley. Originating in China, millet has a long history in beer making in Asia and Africa.
See main article Rice
In spite of the name, buckwheat is unrelated to wheat and is naturally gluten-free. High in protein and beta glucan, often used to provide additional body and foam retention in gluten-free beers.
See main article Buckwheat
Oats can contribute a creamy or ‘silky’ mouthfeel to beer and can have both foam positive and negative effects. Historically they have been used to a limited degree as a brewing adjunct (in oatmeal stouts for example). In current conventional brewing oats are enjoying a resurgence of interest, especially for their haze and mouthfeel contributions to hazy and/or milkshake IPAs. While some countries designate gluten free oats -- grown and processed to mitigate the risk of cross contamination by gluten containing grains -- other countries regard all oats as a gluten containing grain due to the presence of avenin, a protein related to proline in wheat and hordein in barley.
See main article Oats
Sorghum is a grass in the Poaceae family, closely related to millet. It was initially domesticated in northeastern Africa with archaeological evidence dating back to 8,000 BC. The plant became widely grown across the African continent before moving to India, China, and eventually the western hemisphere in the 18th century.
Malted vs Unmalted
Sorghum Syrup that is available in the United States is manufactured by Briess. This syrup is made by cereal mashing unmalted millet and results in a product that can be serve as up to 100% of the fermentable sugars in a recipe. Briess indicates that it does not produce the syrup on dedicated gluten-free equipment, but does sources guaranteed gluten-free sorghum raw material, uses validated Clean-In-Place (CIP) processes with ATP test swabbing between manufacturing runs, and is tested for residual gluten content at a third party accredited lab.
The carbohydrate composition of Briess sorghum syrup is:
- Glucose 6%
- Maltose 45%
- Maltotriose 16%
- Higher Saccharides 29%
Much discussion has taken place around perceived off-flavors that sorghum imparts in a beer, however, some of the most critically-acclaimed and awarded beers in the industry are brewed with sorghum syrup as the primary fermentable ingredient.
There seems to be three main areas to be cautious about when using sorghum syrup in your beer.
- Sorghum beers benefit greatly from using other fermentables in combination with the sorghum. Brown rice syrup, honey, table sugar, malted or flaked grains all help to give a beer greater complexity than just sorghum alone.
- Be careful of caramelization. When using a direct source of heat (burner beneath) don't pour the sorghum directly into the wort with the flame going. The syrup is denser than water and will go straight to the bottom and scorch. Either turn of your heat source while adding the sorghum, dilute the syrup in a bucket and add it to the wort in a thinned out state, or add it later in the boil.
- The yeast nutrient you use matters. Don't use the yeast nutrient containing vitamin B. This is not what the yeast needs in a sorghum-based beer. Instead use a yeast nutrient formulated for low FAN beer or wine.
There has been some discussion on the Zero Tolerance Facebook group about the inherent bitterness of sorghum extract. James Neumeister (Ground Breaker Brewing) suggests that brewers should account for the natural bitterness, estimating the equivalent of about 7 IBUs and keeping the focus on flavor and aroma hops rather than bittering. There has been some scholarly research into phenol and condensed tannin impact on perceived sorghum astringency and bitterness, one review paper noting that "sorghum is unique among the major cereals in that certain sorghum varieties contain significant levels of condensed tannin type polyphenols (≥1%) and that most types contain significant levels of flavonoids." Tannins in sorghum, according to the review paper, "can substantially inhibit malt amylase activity and reduce sugar production during mashing".  White sorghum has lower tannin levels than red sorghum.
Corn can be malted and various corn malts are available from at least two dedicated gluten free maltsters listed on the Resources page.
Corn is the primary fermentable in many traditional central and south American beers, notably chicha. Even after malting, corn can be difficult to mill. A corona mill is recommended over a roller mill, which can be damaged, or damage the person behind the mill when grinding corn.
Quinoa is a pseudocereal native to South America (Andes). It is naturally gluten-free and high in protein. Seeds are coated in bitter-tasting saponins that are usually removed during processing. While quinoa may not be a heavily utilised fermentable for GF brewing, it can be useful in either unmalted or malted form for mouthfeel and head retention.
See main article Quinoa
Starchy roots and vegetables
- Cassava (aka manioc or yuca) produces a very starchy, mild-tasting root that is native to Brazil. In its processed, powdered or pelletized form, it is known as tapioca. A number of alcoholic drinks are made from cassava.
Legumes, Beans, Pulses
Honey and Sugars
Alcoholic beverages made solely or primarily from honey fall under the header of "mead" rather than beer. Honey is naturally gluten free and mead is an occasional topic on the Zero Tolerance Facebook group. Honey is mainly fructose (~38%) and glucose (~31%) Given the simple sugar composition, honey usually does not contribute much body or residual sugar to a beer, and can sometimes be used to increase alcohol potential without the risk of residual sugar. With many different floral sources, there is a spectrum of honey flavors that range from very subtle to strong. Some of the subtle flavors and aromatics can be lost if used during the boil.
- Randy Mosher, Radical Brewing: Recipes, Tales and World-Altering Meditations in a Glass (2004), p. 16
- Free amino nitrogen
- Malted Proso millet The Use of Response Surface Methodology to Optimise Malting Conditions of Proso Millet (Panicum miliaceum L.) as a Raw Material for Gluten-Free Foods
- Behaviour of Malted Cereals and Pseudo-Cereals for Gluten-Free Beer Production
- All About Sorghum, US Sorghum Checkoff Program
- Personal correspondence with Briess Malt & Ingredients Co. (September 2020)
- Briess Sorghum Extract Data Sheet
- Experimental Brewing Podcast #38. Segment starts at 50:30. Sorghum reference at 57m.
- Effects of phenolics in sorghum grain on its bitterness, astringency and other sensory properties (Kobue‐Lekalake et al, 2007)
- 125th Anniversary Review: The science of the tropical cereals sorghum, maize and rice in relation to lager beer brewing (Taylor et al, 2013)
- "Beesource Beekeeping: Honey Composition and Properties". Beesource.com.