Cereals for Spirits Raw Materials for Cereal Distilling

● BASICS OF SPIRITS PRODUCTION iStock.com/narvikk Cereals for spirits Raw materials for cereal distilling

By Billy Mitchell Background pesticide, monitor the fi elds during Spirits production can be schemati- cereal development, harvest the crop This is the ﬁ rst of a series cally described by the simple fl ow and potentially store on farm prior to diagram shown in fi gure 1. selling into the market. It should be of features to support the This simple fl ow diagram will be no surprise then that raw materials already extensive learning explored in greater detail in each of are the number one cost to the spirits the subsequent articles. producer and it is therefore vitally im- material available to those The main cereals used in the portant for cost and effi ciency reasons studying for their General production of distilled spirits in- that the producer maximises the alco- clude barley, maize (corn), wheat, hol recovery from any particular cereal Certiﬁ cate in Distilling – or rye and malted barley. These cereals or mix of cereals. Other major costs of for those just interested in are grown in many different regions energy and labour fall well behind the throughout the world. All of these costs of the raw materials. cereal spirit production. crops are grown on an annual cycle, Cereals are generally traded as a some actually can have two distinct commodity across the world and price ver the coming months I shall growing periods either as a winter or is driven by supply and demand. The Oexplore some of the more practical spring-sown crop but all are harvested annual supply is in part governed by elements employed in the distilling in- during a compact window of opportu- world climates which can have huge dustry which when fully complied with, nity when the crops are ripe and the impact on the quality and quantity of will ensure that the science and tech- weather conditions allow. cereals available in any given year. nology of the production processes are There are many different varie- Demand can change with the introduc- given the greatest chance of delivering ties of these crops and a great deal of tion of new markets such as the fuel the quality liquids required to sustain focus is placed on ensuring that new, industry where fuel alcohol is seen as the many spirits produced throughout disease-resistant and high-yielding a replacement for oil-derived fuels. the world. varieties continue to be developed. Although farmers pay great at- Production in the United States, This is required as older varieties can tention to their crops, they have to United Kingdom, Canada, Ireland and become very susceptible to vari- balance the costs of the various inputs the many other spirits-producing ous crop diseases, they can drop in against the potential value they will countries is regulated by legislation agronomic yield (tonnes/hectare) and realise by increased agronomic yield pertaining to the country of production. can also be hugely affected by climatic and quality – so they will sow and grow In the majority of cases this legislation conditions during the sowing, growing the varieties and cereal type most suit- covers methods of production and the and harvesting periods. able to fulfi l their customers’ needs. raw materials processed therein. This Growing cereals is a costly busi- The scale and size of the operation of article will look at the cereals em- ness for the farmer who has to prepare each farmer will also have an impact ployed in spirits production across the his land, sow and fertilise, poten- on cost – there are huge differences globe. tially apply herbicide, insecticide or in scale between the farmer operating

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Cereal processing

Cereal starch Enzyme (cereal or commercial)

Fermentable sugars Mashing (worts)

Fermented wash Yeast Fermentation (alcohol)

Alcohol concentration/ Distillation separation

Distilled product

in the great plains of the mid-west of allows a regular, balanced flow of each North America to the smaller farms in crop into the market and thereafter Scotland and Ireland for example. into production. Professional, regu- Harvesting the North American Prairie lated and monitored storage of grain between and within storage bins and Short harvest window is hugely important in ensuring cereal therefore must be built to ensure there Most farmers do not deal directly quality is maintained. is no ingress of water. Bird and pest with the spirits distillers, but sell The moisture content of the cereal control should also form part of the their crops to grain merchants or co- at harvest time is generally higher overall storage philosophy. Accurate operatives who will then supply into than desirable for longer term storage record keeping of any treatment, the spirits industries. It is important to – this is obviously dependent on local movement or inspection should also note that traceability throughout this and global climatic conditions and can be a top priority to ensure ongoing supply chain is very important to the vary hugely from relatively dry grain at traceability along the supply chain. spirits industry. ~ 12.0% to very wet ~ 30.0% depend- Storage facilities should be de- I have already stated that the ing on whether dry or wet harvest signed to ensure grain dust is con- harvest period is a short time-window conditions prevail. Storage of cereals iStock.com/kodachrome25 for the farmer to recover his crops with high moisture content can lead from the field – this may not seem to serious deterioration of stocks due important to the end distiller but it to increased risk of mould formation, plays a vital role in ensuring that these self-heating of the grain leading to crops have the best chance of meeting infestation and the production of off the specification laid down by the end odours which could carry over into the producer. final spirit product during the produc- The weather at harvest time can tion process. This drying of the grain also have a major impact on raw mate- after harvest is another added com- rial quality – heavy rains and strong plication in the supply chain and again winds can knock the crops to the must be carried out by professionals to ground and make it difficult to harvest ensure that no damage is done to the without also harvesting unwanted soil crop. debris. Poor set-up of the harvesting equipment can damage cereal grains Grain storage making them more susceptible to There are many conditions which short and long-term damage during must be fulfilled to ensure successful storage. storage. Ideally, cereal temperature The short harvest time-window should be monitored during longer- does not match the maltster’s or term storage of the crops after drying. distiller’s requirements for a stable, Grain storage facilities should be even production plan throughout the designed to allow aeration of the grain year. This leads to relatively long-term should temperatures rise; they should grain storage (from weeks to years) also allow for grain treatment should to balance the different timelines there be an outbreak of infestation and between harvest and production and should allow regular stock rotation Cereal farming on a smaller scale www.ibd.org.uk Brewer and Distiller International June 2016 z 21 l BASICS OF SPIRITS PRODUCTION

Maize (or corn) Wheat Rye Barley trolled as this is an explosion risk and night during transit for any reason they • In the case of barley only, as a source also a risk to human health during must be stored in a secure area which of endogeneous enzymes for the long and short term exposure. The prohibits any interference during the conversion of starch to fermentable silos or general storage bins or grain lay up. carbohydrate during mashing. sheds should be designed and built to The storage of raw materials at allow complete emptying of all grain the production sites must also comply Table 1 gives an overview of the main and grain residues, have access to with the majority of design features raw materials used in the produc- allow regular cleaning and should be for longer-term storage. There should tion of spirits in the relevant country. kept free of oils and greases during be little need to monitor temperature Table 2 gives indicative analysis of four any planned or unplanned mainte- or have the facility to apply treatment of these cereals. I want to use these nance. to the grain as the storage capacity at analyses to explain some of the posi- The design of grain transfer the distillery will be much smaller with tives and negatives for use in spirits equipment, either through mechani- perhaps only days and weeks of stocks production. cal or physical transfer means, must of raw materials on site. These analyses do not represent ensure the grain is not damaged the absolute analytical composition during transfer and dust suppression, The main cereals – composition of each cereal type as they will have a extraction and collection equipment and processing range in composition due to influence should be employed to minimise any The main cereal raw materials used in of variety, agronomy of the soil, cli- potential release of grain dust. All spirits production across the world are mate, fertiliser application and harvest plant and equipment must be designed maize, wheat, rye barley and malted year to name but a few. The key to all for use within a potentially explosive barley. four cereals is that they contain very atmosphere and should be zoned and Other non-cereal raw materials are high concentrations of starch. marked as fit for operation in that used to produce spirits products –such area. Most countries have strict regu- as molasses and grape – but these will Fermentable carbohydrates lation and legislation in this area which not be discussed in this article. Starch is a carbohydrate (a compound must be fully complied with. Cereals are used in spirits produc- containing carbon, hydrogen and The delivery processes employed tion for a number of reasons: oxygen) consisting of a large num- between grain supplier and maltster/ • As a source of starch and subse- ber of glucose units joined together distillery should ensure there is no quently fermentable carbohydrate by glycosidic bonds. In chemistry, a damage to the cereal during transit. during fermentation glycosidic bond or glycosidic linkage Grain wagons should be cleaned prior • For their contribution to the flavour is a type of covalent bond that joins to use and be covered to ensure no of the distilled product (i.e. peated a carbohydrate (sugar) molecule to ingress of water or fouling by birds or and non peated malt in malt whisky another group, which may or may not rodents. If they are to be parked over- production) be another carbohydrate. This polysaccharide is produced by cereals where it is stored primarily in the starchy endosperm and provides the energy for growth. Starch is com- posed of two main molecules:

iStock.com/DavidSucsy Amylose – a helical, linear polymer made up of α – D – glucose units bound to each other through α(1→4) glycosidic bonds. Amylopectin – a highly branched polymer of glucose linked in a linear fashion by α(1→4) glycosidic bonds with branching occurring at α(1→6) links recurring every twenty four to thirty units. Amylose makes up around 20-30% of the starch structure with amylopec- Grain storage facility in Texas USA tin comprising the balance of 70-80%.

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Raw Country of Origin Maize Wheat Rye Barley Material Scotland Ireland USA Canada Japan Thailand India Starch (%) 72.0 69.0 68.0 65.0

Barley Malt Y Y Y Y Y Y Y Protein (%) 9.5 12.5 13.0 12.0

Maize (Corn) Y Y Y Y Y Y Fat (%) 4.5 2.0 2.5 2.0

Wheat Y Y Y Y Y Fibre (%) 2.0 2.5 2.5 5.5

Rye Y Y Y Y Ash (%) 1.5 1.8 2.0 2.8 Table 2: Indicative composition of cereal grains Barley Y Y Y Y The relevance of the structure of Rice Y starch will be reviewed in more detail in future articles on cereal handling, Bajra (Pearl Y starch hydrolysation and mashing. Millet) The key to understanding spirits Sorghum Y production is that these starch molecules can be hydrolysed into smaller Molasses Y Y fermentable carbohydrates which can be further converted to alcohol by the Table 1: Main raw materials used in worldwide spirits production action of yeast during fermentation. In the case of malting barley this raw material, when malted, will produce significant levels of the enzymes required to modify both its own and other cereal grain starches into sugars, including the monosaccharide glucose, the disaccharide maltose, the trisaccharide maltotriose and higher sugars called dextrins. In the spirits industry barley is generally the only cereal used to produce malt although it is possible to malt other grain types.

Choosing cereals for mashing The make-up of component cereals (i.e. recipe) that are processed together to make whiskies and grain neutral spirits is called the ‘mash bill’ or ‘mash recipe’. These differ around the world due to regulations within the country of origin and the type of product to be produced. If you refer back to Table 2 and look at the relative starch contents for each of the four cereals you would expect to achieve a higher alcohol yield from maize, then wheat, then rye and finally barley. This would be the case if each mash bill was similar across the whole distilling industry but for many reasons this is not the case – therefore the task of each distiller is to achieve the maximum alcohol yield for each type of mash bill processed. To summarise, the choice of raw material to use will be governed by: • Product type to be produced • Legislation/regulation pertaining to that product in the country of production • Plant capability and ease of processing • Availability and security of the supply chain • Potential alcohol yield from the type of mash bill and potential costs of www.ibd.org.uk Brewer and Distiller International June 2016 z 23 l BASICS OF SPIRITS PRODUCTION

processing aids required In general the starch and protein (ni- its double husk. The lower starch leads • Actual total volume of alcohol to be trogen) contents are inversely related to lower alcohol yields and thus lower produced in the year (i.e a high starch variety will be low in throughput when compared to wheat • Genetically modified or non-GMO protein and a low starch variety will be or maize. The high nitrogen and high varieties available. high in protein). Soft and hard wheat fibre leads to significant processing varieties can be readily identified by issues due to higher solids and higher Referring again to Table 2 you will see modern analytical methods but can viscosities. Un-malted barley has been that the protein (or nitrogen) levels also be identified by visual inspection processed in grain distilling primar- vary significantly – nitrogen content of a sliced open endosperm – typically ily due to cost – this is no longer the of barley is important for the maltster a soft variety will exhibit a white, fluffy, case as the aforementioned process- who wants to produce very high en- open endosperm while a hard variety ing issues far outweigh any potential zyme malt for grain distilling or high will show a grey/granite, steely, shiny cost benefit. It is recognised that gums soluble extract, high alcohol yield- endosperm structure. such as β – glucans are the main ing malt for malt whisky production. Spirits producers prefer the soft contributory factor to these processing High-nitrogen barley is preferred for varieties as they deliver higher alco- problems. the former while low-nitrogen barley hol yields in general and pose less Barley use in Scotland is now only is preferred for the latter (gener- processing problems when compared used to produce malt for malt whisky ally 1.8% is the cut off with <1.8% N2 with their hard counterpart. This is production and as the source of endog- for pot still malt and > 1.8% N2 for the preferred raw material used in enous enzymes for high enzyme grain high enzymatic malt for grain spirits grain whisky production in Scotland whisky production. production). As is the case for most although some French maize is also There are many reasons for the cereals the actual crop values will be processed. High-protein wheat can choice of raw material for spirits pro- very much dependent on what hap- lead to significant processing issues duction as detailed in my earlier text. pens in the field. due to high gluten content, with a In addition to the previous comments You will also note that maize con- subsequent increase in viscosity in all grains used in the production of tains twice as much fat (vegetable oil) downstream processing of fermented distilled spirits must be: as the other three cereals. This really wash and spent wash. • Free from fungus and moulds plays no significant part in cereal spir- Historically South African White, • Physically undamaged (no broken its production but can add value to the South African Yellow and American No. corns) animal feed produced from the spent 3 corn were also processed for grain • Uncontaminated by other cereals, wash solids residues after distillation. whisky at a time when they were the ad – mix or any other extraneous least expensive commodities in the materials Distilling with wheat world market. But market conditions • Able to meet the analytical specifi- The protein content of wheat is gener- have changed and cereal prices have cations laid down for that particular ally similar to rye and barley. There equalised across the world – and these grain in any given year in the purchase are two main types of wheat grown: are no longer processed due to lack contracts. the hard varieties used in flour, bread of traceability with regard to genetic and pasta production – and the soft modification and the extensive length One common theme throughout the wheat varieties used as feed wheat of the supply chain for these raw ma- supply of these raw materials is the for animals or for spirits production. terials. need to know accurately the weight of The hardness or softness of wheat each bulk of raw material at any point is mainly related to how the starch Barley for malting in the supply chain. and protein molecules are bound You will see that barley has the lowest • Knowledge of the tonnage from any together in the endosperm and to the starch content and contains twice as given field will give the yield per hec- total nitrogen content of the wheat. much fibre as the other grains due to tare of grain, invaluable in assessing the performance of new varieties, use of fertiliser and pesticides etc. • Knowledge of the moisture and weight of wet grain ex-field prior to

iStock.com/elkor drying and moisture and weight of dry grain after drying will give valuable data on efficiency of drying and any potential grain losses. • Knowledge of the weight of raw materials entering and leaving long-term storage will allow calculation of any storage losses due to rodent or any other infestation or any other general loss. • Knowledge of the weight arriving at the spirits production facility will be the starting point for accounting purposes within the distillery and will allow accurate payment for the goods delivered.

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It will be most important to account for these raw materials throughout the production processes for efficiency and quality reasons and to ensure that alcohol yield is maximised for each mash bill processed – this will also be covered in ensuing articles.

Regulation and raw materials As explained earlier there are specific regulations governing the use of raw materials in the production of distilled spirits – some are very Irish whiskey Canadian whisky specific while others are less so. I The Irish Whiskey Act, 1980, defines Food and Drugs Regulations C.R.C. will include some of these regula- the raw materials which can be pro- (Consolidated Regulations of Canada) tions to explain the restrictions in cessed to make Irish whiskey. In these defines the raw materials which can be four of the largest spirit producing regulations ‘Irish Whiskey’ means: processed to make Canadian whisky, countries – again this is not the full • The spirits shall have been distilled in Canadian rye whisky or rye whisky. legislative framework but that which the State or in Northern Ireland from a They shall: relates to raw material use. I recog- mash of cereals which has been: • Be a potable alcoholic distillate, or nise that there are other very large • saccharified by the diastase of malt a mixture of potable alcoholic distil- spirits producers in various countries contained therein, with or without lates, obtained from a mash of cereal throughout the world – unfortunately other natural diastases grain or cereal grain products sac- it is not possible to include them all, • fermented by the action of yeast charified by the diastase of malt or but the same principals apply. • distilled at an alcoholic strength of by other enzymes and fermented by less than 94.8 % by volume in such a the action of yeast and other micro- Scotch whisky way that the distillate has an aroma and organisms The Scotch Whisky Regulations 2009 flavour derived from the material used. • Posses the aroma, taste and charac- defines the raw ter attributed to Canadian whisky materials which American whiskey • To be mashed, distilled and aged can be processed There are both federal in Canada. to make Scotch and state codes which whisky. These define the raw materials Raw material specifications specify that ‘Scotch used in the production of I do not intend giving detailed specifi- whisky’ means a American whiskey. The cations for each of the raw materials whisky produced in regulations vary depend- used in the production of distilled spir- Scotland: ing on spirit type how- its – I will however give some indica- • That has been ever American whiskey tion of how these specifications may be distilled in Scot- is a distilled beverage drawn up. land from water produced in the United and malted barley States from a fermented Wheat for spirits production: A typical (to which only whole grains of other mash of cereal grain. The purchase specification could include: cereals may be added) all of which production of American • Moisture (% wt/wt) have been: whiskey is governed by • Specific Weight (kg/hl) • processed at that distillery into a Title 27 of the US Code • Hardness (soft/hard) mash of Federal Regulations. • Protein (% wt/wt) • converted at that distillery into a Some key types listed in • Predicted Spirit Yield (la / tonne) fermentable substrate only by endog- the code include: • Ad-mixture (% wt/wt) enous enzymes systems, and • Rye whiskey, made from • GM or non GM. • fermented at that distillery only by mash that consists of at • Variety – it is unlikely this would be the addition of yeast least 51 % rye. included in purchase specification). • That has been distilled at an alco- • Rye malt whiskey, made holic strength of less than 94.8 % by from a mash that consists Barley for spirits production: A volume so that the distillate has an of at least 51 % malted rye typical purchase specification could aroma and taste derived from the raw • Malt whiskey, made include: materials used in, and the method of, from a mash that consists • Moisture (% wt/wt) production. of at least 51 % malted • Specific Weight (kg/hl) barley • Protein (% wt/wt) It further defines single malt whisky as • Wheat whiskey, made • Predicted Spirit Yield (la / tonne) a Scotch whisky that has been distilled from mash that consists of • Ad-mixture (% wt/wt) in one or more batches:- at least 51 % wheat • GM or non GM • at a single distillery • Bourbon whiskey, made from mash • There may be set limits for mycotox- • from water and malted barley without that consists of at least 51 % corn (maize) ins and other foreign seeds the addition of any other cereals and • Corn whiskey, made from mash that • Variety – it is unlikely this would be • in pot stills. consists of at least 80 % corn (maize). included in purchase specification). www.ibd.org.uk Brewer and Distiller International June 2016 z 25 l BASICS OF SPIRITS PRODUCTION

can be processed as either green or • No insect or rodent damage dried malt. Green malt is the name • No evidence of prior infestation given to malt at end of germina- • No off odours of any kind tion and prior to kilning. Green malt • No moulds could have a moisture of up to 45% • No mineral oil to be present wt/wt while dried malt is likely to • Transport to be provided in clean have a moisture of less than 7.0% wagons or railcars etc. wt/wt. Green malt has a very short, limited shelf-life as the high mois- Neutral spirit and fuel alcohol ture content quickly leads to deterio- Many of the raw materials detailed ration and loss of activity, infection, can also be utilised in grain neu- souring and matting. Dried malt has tral spirit production or fuel alco- no such handling problems and can hol production for the exact same be stored for weeks and months reason as those given for potable prior to use. spirits production – i.e. a very high starch content which can be readily Distilling malt (i.e. malt as the source of processed into ethyl alcohol. In fact enzyme and starch): A typical specifica- some but not all of these business tion could include:- process whole grains while others • Barley variety process cheaper alternatives which • Barley type (2 or 6 row) are produced from starch, gluten or • Moisture (% wt/wt) other extract processes. There is less • Enzyme potential (Alpha and Beta specific regulation on neutral spirits © Scotch Whisky Association © amylase – DU (Dextrinising Unit) and and fuel alcohol production and there DP (Diastatic Power respectively)) are no restrictions around enzyme • Predicted Spirit Yield (la/tonne) use, pH adjustment or any other • Total Soluble Nitrogen (% wt/wt) process aids. • Soluble Extract (% wt/wt) • Homogenity Some follow-ups • Friability (over / under / uneven I have tried to provide a general over- modification) view of the cereals utilised in some Barley for malt production: A typical • Ad-mixture (% wt/wt) of the spirits industries – I did not purchase specification could include: • MC potential – the potential to pro- attempt to cover all spirits produced • Moisture (% wt/wt) duce ethyl carbamate during spirits or raw materials processed. If you are • Viability or Germinative Capacity (%) production. a novice to the spirits industry then • Total Nitrogen (% wt / wt) • Screenings (% wt/wt) I will leave you with a few follow-up • Ad-mixture (% wt/wt) • Peated – Non-peated malt (for questions which might help you get • Grain size or Screenings - Sieve Test peated malt ppm total phenols) to grips with the specifics of your own (Grain size analysis % on a range of business raw materials, regulation and sieve sizes) Maize (corn) for spirits production: A products. • There may be set limits for mycotox- typical specification could include: • Get a copy of the relevant legisla- ins and other foreign seeds • Moisture (% wt/wt) tion/regulation for your products and • Variety – this could be included in the • Specific Weight (Bushel Weight) lbs / kg country of operation – the internet is a specification. • Protein (% wt/wt) good starting point for this! • MC potential – the potential to pro- • Starch (% wt/wt) • Talk with the relevant people duce ethyl carbamate during spirits • Broken corns / admixture (% wt/wt) within your business to find out how production. • GM or non GM your specific raw material supply • There may be set limits for mycotox- chain/chains operate – this might Grain distilling malt (i.e. malt used as ins and other foreign seeds. include operations and procurement the enzyme source): A typical specifica- teams! tion could include: Rye for spirits production: A typical • Talk with your quality department • Barley variety specification could include: to find all the detail around your raw • Barley type (2 or 6 row) • Moisture (% wt/wt) material specifications • Moisture (% wt/wt) • Specific Weight (Bushel Weight) lbs/kg • Talk with your quality and operation- • Enzyme potential (Alpha and Beta • Broken corns / admixture (% wt/wt) al teams to find out what can go wrong amylase – DU (Dextrinising Unit) and • GM or non GM with your raw material supply – what DP (Diastatic Power respectively)) • There may be set limits for mycotox- impact does this have on your particu- • Limit Dextrinase ins and other foreign seeds. lar role? What impact does this have • There may be set limits for mycotox- on the operation of your plant? ins and other foreign seeds Regardless of the detail included in the • MC potential – the potential to pro- measureable detailed specifications Answering some if not all of these duce ethyl carbamate during spirits for each type of raw material, there questions will help you get behind production will also be more generic statements the detail of your most expensive Malt used in spirits production as which apply to all cereal raw materials raw material in the spirits industry – the source of endogenous enzymes delivered such as: good luck!

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