Usually adjuncts are unmalted grains which supplement or replace the malted barley. Oats, corn, rye, millet, sorghum, teff and buckwheat are just a few of the many starch-rich adjunct grains which can be fermented into beer. Adjunct grains are normally considered extras, and not an integral ingredient when brewing beer.
Knowing this, the idea of brewing a beer with 100% adjuncts is surprising. Can you brew beer without barley? Is it still beer? More importantly, why would you want to?
One reason is the sustainability advantage gained by brewing with locally sourced ingredients. Another is to produce a gluten-free beer.
Gluten is a storage protein or prolamin found in wheat, barley and rye cereals. For some people consuming gluten triggers an auto-immune disorder known as celiac disease. An inflammatory response to the gluten prolamin in the lower intestine causes difficulties absorbing nutrients from food. Undiagnosed celiac disease is a serious condition estimated to affect around 1% of the population, and the only cure is to follow a gluten-free diet. Other conditions such as gluten allergies, as well as fashionable diets encouraging people to avoid gluten have led to increased demand for gluten-free products. Beer is no exception following a gluten-free diet should prevent the enjoyment of a good beer.
It is possible to produce a gluten-free, or more correctly a gluten-reduced beer using enzymes to breakdown the gluten proteins in a traditional beer. Unfortunately, this process does not remove gluten completely. Even after enzymatic digestion residual gluten peptides can remain, meaning gluten-reduced beers may not be completely safe for celiac sufferers. Brewing with 100% gluten free adjuncts provides an alternative solution to this problem, and it is possible to brew innovative and tasty gluten-free beers from these ingredients.
While beer is traditionally brewed with malted barley, the truth is that with the right enzymatic toolbox beer can be brewed from any starch-rich material. There are many naturally gluten-free sources of starch such as corn, millet, rice, sorghum, cassava and teff. To brew using these raw unmalted starch sources, it is necessary to know their gelatinization temperatures and enzymatic contents. Starch must be liquified to create smaller fermentable sugars, and proteins must be solubilized to create the necessary Free Amino Acids (FAN) needed for adequate yeast growth.
Gelatinization temperature is the temperature at which a starch suspended in water begins to swell as the suspension is heated. In sufficiently hot water, the intermolecular bonds of the starch molecules begin to break down, allowing it to absorb more water. Amylose and amylopectin chains dissolve and form a gel. Gelatinization temperatures vary widely, however, most gluten free starch sources have higher gelatinization temperatures than malted barley.
When brewing with 100% unmalted adjuncts, a cereal cooker may be needed to heat the mash above the required gelatinization temperatures (85-95°C). Alternatively, a special mashing regime, with an extended pause at 78°C, can be used in a normal mash tun. Adding DuPont exogenous enzymes such as AMYLEX® 5T, DIAZYME®MA and ALPHALASE®THP at the mashing stage helps to liquify and gelatinize the adjuncts. As little is currently known about the cell wall breakdown of adjuncts during the mashing process, fine milling is required to achieve adequate yield and cell wall break down. This means mash filtration is essential.
It is also important to consider the low endogenous enzyme levels of many gluten-free cereals. Adding exogenous enzymes to the adjuncts helps to achieve a similar standard of enzymatic activity to malted barley. A glucoamylase such as DIAZYME®TGA or a maltogenic α-amylase such as DIAZYME®MA increases the levels of fermentable sugars available. Different exogenous enzymes may be required, depending on the selected raw materials. In the final stages of brewing dry hopping can be used either during or after fermentation to enhance hop flavor and aroma.
With a willingness experiment with new ingredients, and expert advice from our brew masters, it is easy to brew a delicious gluten-free beer using 100% adjuncts. Talk to us at DuPont and begin brewing your own.