Coeliac Disease, Brewing and Gluten Free Beer

Robert HinterdingSilly Yak Foods Pty. Ltd

PO Box 707,Northcote 3070

rhh@sillyyak.com.au

Peter AldredSchool of Science & Engineering

University of BallaratPO Box 663,Ballarat, 3353

p.aldred@ballarat.edu.au

Abstract

Coeliac Disease is an autoimmune condition in which a reaction to a sequenceof amino acids in prolamins from the cereals wheat, rye, barley, oats, spelt, kamutor their hybridised strains causes damage to the small intestine. This leads tomalabsorption problems and an increased risk of certain types of cancer. The onlycure is to avoid consuming all food which contains these cereals. The commonname for these prolamins is gluten and hence coeliacs must adhere to a glutenfree diet. The current estimate is that at least 1% of the population is affected bycoeliac disease, making it the most common of the genetic disorders. Adheringto a gluten free diet is difficult as many processed convenience foods containgluten. To assist people with food intolerances and allergies, ingredient listingand allergen labelling is becoming mandatory worldwide. There are also separaterules on what can be labelled as gluten free. Beer is one beverage coeliacsare advised to avoid and until recently there has been no acceptable alternative.Whilst beers made from gluten free ingredients are now becoming available, thereis still confusion about whether beers brewed from barley are safe for coeliacsbecause of the limitations of the currently available gluten testing. This paperexamines the issues of whether normal beer is gluten free, the limitations of thecurrent tests and the regulatory environment of allergen listing and gluten freelabelling. We also examine the grains and methods which can be used to makebeer from naturally gluten free ingredients and the problems encountered in bothmalting and brewing with these ingredients.

1 IntroductionCoeliac Disease is a condition which about 1% of the population [2, 15] suffers fromand these people must avoid all food and drink made from wheat, rye, barley, oats,spelt, kamut or their hybridised strains. As there is no cure, Coeliacs are advised to

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follow a gluten free diet where products made from these grains are avoided. Avoid-ing all food and drink made from these grains is difficult. The compulsory inclusionof ingredient lists and allergen labelling, where it is required, has made the task easier.There are also regulations on what may be labelled as gluten free [3]. In Australia tobe labelled as gluten free, food must contain no detectable gluten 1 and not contain anyoats or anything derived from a malted gluten containing grain. In Europe most coun-tries have adopted the level of 200 ppm set by Codex Alimentarius, although somecountries have set the allowable level to 20 ppm. However the current allowable levelset by Codex Alimentarius is being reconsidered [4]

For most foods, acceptable alternatives not containing these grains have been de-veloped, but some products have been more difficult. Beer is one of these. Coeliacsare advised not to drink beer but to drink cider, wine or some of the spirits instead[15]. The problem is for a lot of people there is nothing like a beer. Some Coeliacsare tempted to still drink beer, and this problem has been made worse by some of themanufacturers of beer claiming that their beer tests low gluten or gluten free when thecurrently available test is known to give false negatives for beer brewed from barley[11].

The requirements for ingredient listing and allergen labelling are not uniform forall food and drinks, and the requirements also vary between countries. Also, as theresearch into Coeliac Disease progresses and better and more comprehensive tests aredeveloped for detecting the level of gluten in food and drinks, the requirements andthe testing required are becoming more stringent.

In the last few years a number of beers have been developed especially for Coeliacsusing gluten free grains. The grains used include rice, maize, buckwheat and sorghum.While the beers were first based on unmalted grains, beer based on malted gluten freegrains are now becoming available. The malting and brewing using gluten free grainsis more difficult, and there are also contamination issues which must be addressed. Wediscuss the problems of making beer from these grains, and the different processingrequirements.

The paper is organized as follows. The next section discusses Coeliac Disease.Section 3 discusses the ELISA test, and Section 4 looks at brewing gluten free beer.Section 5 concludes the paper.

2 Coeliac DiseaseCoeliac Disease is an autoimmune condition in which a reaction to a sequence ofamino acids in prolamins from the cereals wheat, rye, barley, oats, spelt, kamut ortheir hybridised strains causes damage to the small intestine. This leads to malabsorp-tion problems and an increased risk of certain types of cancer. The only cure is toavoid consuming all food which contains these cereals. The common name for these

1the current limit of dedection is 5 ppm.

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prolamins is gluten and hence coeliacs must adhere to a gluten free diet.This condition was described in 250 AD by Galen, a Roman doctor, but it was not

until after the Second World War that its causes were discovered. Dicke [8], a doctorin the Netherlands, found his Coeliac patients felt much better during the famine at theend of World War II when grain products were very scarce, and became worse againafter the war when bread and wheat flour was flown in from Sweden, and identifiedwheat as one of the causes. Since then a lot more has been discovered about thedisease, and also the role of the immune system which was discovered in the 1980s.

The disease has a genetic background, but as about 30% of the population [2] hasat least one of the genes, this is not sufficient to indicate the presence of the condition.There must some triggering event as well. Also, the incidence is higher in countriessuch as Ireland and Finland where wheat was introduced more recently.

The rate of diagnosis has increased as doctors have been educated about the diseaseand its symptoms. One of the problems is there is no typical set of symptoms, some ofthe blood tests used are not conclusive, and some sufferers have no obvious symptoms.

The advent of compulsory ingredient listing and allergen labelling has made iteasier to determine which food products contain gluten. In some countries there arealso regulations on when foods may be labelled gluten free. Unfortunately, theserules are not consistent between countries. The criteria for labelling food gluten freecan be based on testing only (Europe), and exclusion of certain ingredients (oats andmalted gluten containing grains) with testing (Australia and New Zealand).

3 ELISA TestThe current commercially used test for the presence of gluten is the ELISA test2, thistest is known to detect the presence of gluten from oats and barley poorly [12, 11, 22],and is even worse if the grain has been enzymatically processed or charred. It is forthis reason that food cannot be labelled gluten free if it contains oats and maltedgluten containing grains in Australia and New Zealand [3, Sec 1.2.8].

Some manufacturers still say that their products test gluten free or low glutenwhen these ingredients are used, also some products currently labelled as gluten freein Australia still contain ingredients such as malt extract.

The current ELISA test was developed to detect the gliadin protein in wheat, it doesthis well as it can currently detect levels down to 5 ppm, but does not detect the hordeinprotein from barley well at all. A new ELISA test is being developed in Europe, theR5ELISA test [22, 23, 12], this test can detect lower levels of the gliadin protein, andis also highly reactive to the hordein protein from barley.

A example of the use of the new R5ELISA occured in November 2005 when theCoeliac Society of the UK sent an email to all its members that it no longer considereda large range of breakfast cereals flavoured with barley malt to be gluten free. In the

2This test was developed by the CSIRO

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UK foods must contain less than 200 ppm gluten as measured by the current ELISAtest to be labelled as gluten free, but testing with the new R5ELISA test revealedlevels above the 200 ppm threshold.

4 BeerTo make a gluten free beer, because of the labelling requirements and the limitationsof the the current ELISA test, we are restricted to using only gluten free ingredients,and we have no reliable way of measuring the level of contamination from ingredientsor from the brewery equipment used also to make normal beer.

On the question of ingredients, we took the conservative and safe approach of usingno ingredients which contain, or are derived from, or propagated on gluten containinggrains. This meant that liquid yeasts could not be used as they are propagated on barleywort, and Australian produced dextrose could not be used as it is derived from wheatstarch.

Some of the gluten free beers around the world are based on a hopped mead(Passover Honey Beer, USA), sugar syrups (Hambleton Ales, UK), unmalted grains(Bi-Aglut, Italy) or malted sorghum (Bards Beer, USA; Silly Yaks and OBriens, Aus-tralia). We decided early on to explore the malting of sorghum as a basis for makingthe beer for a number of reasons:

We tested beer made from rice, buckwheat and sorghum, and found the beermade from sorghum had the best taste.

The malting of a grain gives important flavour contributions as well as develop-ing the enzymes needed to convert the starches to sugars.

A lot of sorghum is grown in Australia and it is available at a reasonable price. Sorghum has been used for making African native beers for thousands of years[20, 21].

Published research is available on malting sorghum and using sorghum to makeEuropean style beers.

4.1 Malting SorghumSorghum is a tropical cereal which is reasonably drought tolerant and is grown ex-tensively in Africa [6], Asia, Australia and the USA. It will grow in areas too hot togrow barley and wheat, it is used for human consumption in Africa and Asia, but inAustralia and the USA it is used primarily as stock or bird feed.

The use of sorghum as an ingredient or adjunct in brewing beer was explored in thepast, but it was thought it would not develop sufficient enzymes to convert itself, and

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its high gelatinisation temperature was seen as a disadvantage in using it as a cheapsource of starch.

In the 1980s Nigeria restricted the importation of barley and barley malt and re-search into the use of sorghum as an alternative to barley for making European stylebeers was undertaken seriously. It has since been found that sorghum malt does de-velop sufficient enzymes to convert itself, the problem had been the way it was malted.To maximise the development of enzymes the steeping and germination temperatureof sorghum needs to be around 30oC [13, 14, 17, 16, 18, 19, 5].

The differences between sorghum and barley malt are summarised in Table 1. Theamylase enzymes in sorghum malt are more heat sensitive than those of barley. Thiscombined with the lower levels of enzymes means that sorghum malt can only bekilned at low temperatures otherwise too many of the enzymes will be destroyed. An-other problem with sorghum malt is that the cell walls are not destroyed well duringmalting because of the low levels of glucanase produced during malting [9, 1].

As a normal barley malting plant is not set up to work at the elevated steepingand germination temperatures for malting sorghum, a small malting plant near SwanHill was modified so that sorghum could be malted. Equipment was installed so thatthe steeping water could be heated to the required temperature, a water filtration wasadded to ensure the steeping water was clean and sterile, and the steeping process wasautomated as frequent changes of steeping water and multiple airrests are done tominimise the chance of bacterial or fungal infections at these elevated temperatures.

Table 1: Summary of malt differences

Malt DP amylase amylase losses huskBarley high mod high low yesSorghum low high low high no

4.2 Brewing with Sorghum MaltIn brewing with sorghum malt, the following problems need to be addressed:

High gelatinisation temperature in the range of 68oC 78oC. Low diastatic power and low levels of amylase Amylase enzymes are more heat sensitive than those of barley. Cell walls not well degraded during malting. Sorghum has no husk.

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To get a good rate of extraction from sorghum malt, a hammer mill is generallyused to grind the malt, this helps with the problem of poor cell wall degradation, andas there is no husk to preserve has no disadvantages. A further advantage of using ahammer mill is that it can be dedicated to milling gluten free grains and hence removesone of the major sources of contamination in a brewery as it would be extremely dif-ficult to clean the normal malt mill.A glucanase rest (4045oC) and the addition of glucanase can also be of help.

The high gelatinisation temperature [9, 1] and the fact that the enzymes in sorghumare more heat sensitive, means that the brewery must be capable of a decoction mash.An infusion mash is ineffective as by the time the starches have been gelatinised, theamylase enzymes, especially the amylase have been destroyed. Also the lowdiastatic power means a long saccharifiaction rest must be used, and the temperaturemust be controlled well so as not to denature the amylase.

The method which seems to work best is a slightly modified form of a Schmitzprocess decoction [7]. This involves removal of the clear wort from the top of themash after a protein rest, and boiling the remaining thick wort, then cooling the boiledthick wort down and then adding the thin clear wort back so that the saccharificationrest can now proceed. The purpose of this process is first to dissolve the enzymes in thewort, then to recover sufficient of the enzymes with the thin wort and keep them safewhile the thick wort is boiled to gelatinise the starches. When the thick boiled wort iscooled down and recombined the with the thin wort, we have gelatinised starches andactive amylase enzymes so the conversion of the starches to sugars can proceed.

To separate the clear wort from the grist either a mash filter must be used, or ifusing a lauter tun then rice hulls need to be added so that a filter bed can be formed.The sorghum grist is much denser than barley grist, this can cause problems duringbrewing as it can settle into quite a solid mass if left to settle for too long.

The brewing plant must be thoroughly cleaned before brewing a gluten free beerto remove all traces of gluten from brewing normal beer. A separate malt mill mustbe used as it is not possible to clean satisfactorily, and heat exchangers should be bethoroughly cleaned.

The changes made at the brewery have included duplication of the malt milling andhandling equipment and installation of a separate pump to transfer the thin clear wortfrom above the settled grist in the mash tun. A continuing problem is how to quicklycool down the boiled grist before it is recombined with the thin wort which containsthe active enzymes.

A further problem identified with sorghum malt is that it is not as stable a barleymalt, and the diastatic power of dropped by 29% after six months of storage [10].

4.3 FermentationThe issues here are:

If using dried yeasts, only a limited range is available.

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The yeast can produce different esters than those expected. The balance of sugars is different.The flavour profile you get with sorghum worts is not the same as you would get

using the same yeast in a barley wort, the ratios of the various amino acids and alsothe ratio of the various sugars is different. We have found that yeast which produceslow levels of esters will help reduce the sourness and astringency that sorghum beerstend to display.

Sorghum worts produce a quite different balance of sugars [9],there is much moreglucose, maltotriose and fructose produced (see Table 2). The high levels of glucose(30%), can mean that some yeasts lose the ability to ferment maltose [24].

Table 2: Percentage of Sugars in Sorghum and Barley Worts [9]

Sugar Sorghum BarleyFructose 3.5 1.8Glucose 29.9 11.9Sucrose 0.4 4.2Maltose 52.5 70.5Maltotriose 13.7 11.7

Also if the yeast cannot ferment maltotriose, the beer may end up sweeter thandesired because of its level in the final beer.

5 Summary and ConclusionsThe development of a gluten free beer based on malted sorghum has been achieved,but the amount of research and the development time was much more than expected.Malting sorghum and brewing a beer based on sorghum malt is basically the same asusing barley, but it is all the details that are different. Discovering these details andhow to deal with them is what has taken most of the time.

We have shown that it is possible to produce a gluten free beer which is acceptableto both coeliacs and noncoeliacs alike. The consistent comment we get is that ittastes like beer.

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