Malt - Unravelling the Mystery
A maltster reveals all!
Ivor Murrell Director General (Retired), The Maltsters Association of Great Britain
Maltsters are continually surprised by how little is known about what they do, and why they do it. Perhaps we have overplayed the 'art and mystery of malting' over the years to the extent that it has become a 'secret'? We now find that some people are beginning to think that beer is made from hops, and whilst nobody would deny the significance of hops, it does indicate that malt should reveal its true importance. A modern technique for unwrapping information is the question and answer system, so I will use that format to show the importance of malt, and remove some of the mystery.
Why is malt so undervalued?
The answer is that, outside the industry, most people know little, if anything, about it, yet malt has a long history, and a very strong story, and it is worth telling.
For people who grew up in the 1950's the word MALT is likely to be synonymous with liquid malt extract, which many mothers spooned into their children because they believed it would help their development. Today malt extract is a very important ingredient for natural flavouring in the food industry. You could be eating it in breakfast cereal, or even in ice cream, and be given a clue of its presence in some products such as 'Maltesers'. However, about 96% of the 16.5 million tonnes of malt made in the world is used as the main ingredient, with water, to make beer. Malt is extremely important in Scotland for malt whisky, but only represents about 3% of world malt use.
What is malt made from?
It is made from the grain harvested from those waving fields of barley that ripen in the summer sun. It is predominantly made from barley, but other cereals can be malted. Malted wheat is used to make some types of bread, and can also be used to give different qualities to 'wheat beers'.
The vast majority of malt is made from barley, not just any type, but malting barley. This special barley has taken hundreds of years to be improved by selective breeding into the varieties that we use today. It takes many years to develop a new barley variety, from the original cross breeding of a pair of barley types to a successful commercial crop of sufficient tonnage for malting. In the last three or four years of this process, experts from malting, brewing and distilling carry out tasks to evaluate the new barleys, in Scottish and English work groups. This geographical split is important not only because of the differing needs of cereal cultivation in the two areas, but also because of different malt type requirements.
For the last 80 years the UK has led the way in a continual search to produce the best type of barley for malting.
Farmers have developed their skills to enable them to grow the high quality barley that maltsters need. By their choice of barley, when they plant it, and how they 'feed it' farmers can influence what the protein level is in each ear of corn. Sunshine and rain also have a big impact on grain quality.
A different protein content in malting barley is needed for each specific malt use. Most whisky malt is made from low protein barley, as the lower the barley protein content (measured in terms of nitrogen), the more starch there is in the malt made from it, and whisky distillers want as much starch as they can get to convert into malt whisky in their distillery. Brewers use malt made from a wide range of protein levels in barley, from 9% to 12% depending on the type of beer being brewed, and the brewing equipment.
Farmers growing malting barley have to know what type of barley and its protein level their customers' want, and grow their grain very carefully for that specific market.
They then have to harvest it very carefully, and not damage the husk of the grain; otherwise it will not malt uniformly.
Damaged grain will take up moisture faster when soaked under water (steeping) in the first stage of malting.
Combine photo by Paul Glendell, supplied by courtesy of English Nature Image Library.
Having safely gathered in the harvest, with ripe, plump, undamaged grains of barley, either they, or others, must then take care to store the grain safely. Each corn of barley is a living seed, and if it is to be changed into malt it has to be able to germinate. To protect the 'germinative capacity' of each corn (i.e. its ability to grow), the grain is best dried to below 14.5% moisture content for long-term storage, and the drying process itself must be controlled, as too much heat will also damage the grain.
After all this careful selection, growing, harvesting, drying and storage of malting barley, the maltsters then use their knowledge to decide if the barley being offered will make the type of malt that their customers want. If they can match the quality of barley being offered by the farmer to a type of malt they can make from it for a customer, then they will buy the farmers barley. They then need to use their skills to change the barley into malt.
What is the difference between barley and malt?
At first glance there is very little difference between a corn of barley and a kernel of malt. The keen eye would notice that the outer husk of the malt does not seem as tightly stretched as that on the malting barley, but otherwise it still appears to be a barleycorn. However, all becomes clear when you bite each of them. The barleycorn is difficult to bite, and its white starch centre is very hard, with little distinctive taste, but the malt bite is completely different. It bites easily and the flavour of the malt then floods into your mouth. Malt has its own distinctive flavour with overtones of sweetness from the natural sugars that have been formed during the malting process.
How has that change come about?
By controlling an entirely natural effect of wetting the corns of barley to make them grow, and then stopping the process with heat when changes inside the corns have reached the point the maltster wants to preserve.
In simple terms each corn of barley consists of three parts:
a) an outer husk
b) that is wrapped around a piece of hard starch,
c) to which is attached the embryo, or germ, which has been stained red in the photograph by tetrazolium salts, showing that the germ has full germinative capacity
The embryo is the material that will develop into the roots and shoots of a new barley plant, and the piece of hard starch is the food package it will consume to do that, whilst the husk protects both.
The maltster's skill is the finely controlled use of water, during the process known as 'steeping'. The maltster has to raise the moisture content of the grain to around 46% moisture to enable the malting process to take place. The steep can also be 'roused' with air, to make sure the water uptake is even through all the grain.
After steeping the grain is allowed to germinate for a few days to make the required changes, or 'modification', within the barleycorn. The embryo sends enzymes into the hard starch that will change the starch into a different substance, as cool air is passed around the grain to control the rate of change.
The embryo's purpose at this point is to produce a foodstuff that can then be used to produce roots and shoots. During this part of malting the grains are called 'Green Malt'.
Note the small rootlets on the Green Malt. The ridge that can be clearly seen on the corns is the acrospire. If growth was allowed to continue this would become the new shoots of the barley plant, producing leaves and stems.
The hard-hearted maltster applies heat to 'lock up' the process in the Green Malt before the germ can start to use the modified starch. Extra heat is then applied to give the required malt flavour and other analytical specifications asked for by the maltster's customer. The result of all this skill can be appreciated as soon as you bite into a kernel of malt. The starchy endosperm of the hard barleycorn has little distinctive taste, but the malt bite is quite different; it is 'crunchy' and the malt flavour floods into your mouth.
How does the maltster vary the flavour of malt?
The flavours and colours in malt have always been attributed to the maltsters' skills, and are mainly linked to the amount of heat used in kilning, or roasting for highly coloured malts, and how it is applied. Brewing Research International has been unpicking some of the mystery in this process now for several years. About ten years ago they started working on a scientific approach of defining flavour in beers, and it was a natural progression about seven years ago to look at flavours coming from the brewer's main raw material, malt. Spider diagrams were used, to connect points marking levels of taste of a variety of flavours ranged around a central point, rather in the form of a spider's web. The image of each 'web' gave a profile of the flavour being tested. This work is now being taken further at BRi, trying to determine where the flavour is coming from in the malt and malt products. If this is successful it may be possible to model the process requirements to help ensure 'right first time' flavour development in malt.
Some examples of Spider Diagrams, showing how different flavours are recorded
Comparison of a wide range of results helps to narrow the search for such process control. Flavour is one important aspect of malt, but how well the brewer can process malt into good beer is a fundamental commercial requirement. UK Maltsters are fully aware of this fact, but had no scientific evaluation of how malt made in the UK compared to other malts made by their overseas competitors.
Have UK Maltsters tried to benchmark their malt against their overseas competitors?
The MAGB persuaded the Home Grown Cereals Authority that such knowledge would be very useful, and HGCA Project number 238 was carried out in 2001 to produce some factual information. Six malts with a very similar analytical specification were drawn back to the UK from overseas brewers, including malts made in the UK, and were submitted by BRi to a wide range of tests to determine brewing processability. Obviously such a limited range of samples could not be considered as totally representational, but as only the UK malts were identified in origin, it was a considerable relief to learn that they took first and second place in the trials. UK maltsters found that this project answered several of their questions. The full AHDB Cereals & Oilseeds report is still available on the MAGB website. CLICK HERE TO READ OR DOWNLOAD.
Modern malting uses technology wherever it can, to ensure fine process control, and to produce high quality malt with minimal manpower. Yet however 'modern' the malting equipment appears, it is still controlling an entirely natural process of change within the grain.
How was the natural process of malting discovered, and even more surprisingly how was it discovered that you could use the malt produced to make beer?
Nobody knows for sure, but rather like roasted meat, it was probably a lucky accident, or more likely a series of lucky incidents. Man has probably cultivated barley and wheat for around 12,000 years, and malting is thought to have taken place for about half that period. Dr Dennis Briggs in 'Malts and Malting' suggests that malting is the oldest biotechnology. Even today research is still undertaken on what happens during the malting process, so although maltsters rightly consider themselves 'experts' they do not pretend to know everything about their art.
It is likely that the first discovery was that natural yeast could mix with ground up barley or wheat flour to produce bread, although it probably took some while to understand why some baked grain flour was flat whilst others were 'raised' by the yeast.
Perhaps the next exciting discovery was probably that sprouted (or germinated) grain produced a different flavour when baked as bread. Its known that in ancient Egypt bread making and brewing occurred at the same locations, so it is perhaps not unlikely that it was a baker who discovered how to make beer?
An ancient loaf of bread could have contained malt, in the form of germinated barley that had been baked, plus the yeast necessary to make the bread rise. Drop that into a container of water, and leave it for a few days and you would produce a liquor rich in natural sugars and starch, which the yeast could eat and within its cells produce alcohol as a by-product. The first beer! Who was the brave person who decided to taste it rather than throw the dark frothy liquid away? This was an unsung hero indeed!
What did the earliest beers taste like?
We would not recognise the flavour of beer drunk at those times, indeed it would be more accurate to call it ale, as it did not contain the bitterness flavour supplied from hops. Ale was made from fermented malt liquor, and a range of plant material was added over the centuries to give flavour change. Hops were not used for that purpose in the UK until about 500 years ago, and were not welcomed when first introduced!
Malt is a 'natural product', so does it contain anything of value in the diet?
Unlike the previous areas of interest, research into the health benefits of malt has only taken place in comparatively recent times. We are still learning what malt has to offer, but the early information is encouraging.
In the UK work has been funded by the Home Grown Cereals Authority to look at the increase through malting in the beneficial substance Folate (Vitamin B9) in cereals, carried out by Brewing Research International under Dr Caroline Walker. This research showed that malting increased the level of Folate in barley by two to three times the original level. Folate is considered to be one of the vitamins lacking in Western diet.
Elsewhere, other researchers (J.F. Ma et al in 2003) have been looking at the silicon content in barley grains, which is thought to be essential in the diet for the proper development of collagen and bones. In their reported findings they emphasize that silicon in the diet may prevent the absorption of aluminium in the gut. Aluminium is thought to have a possible link to Alzheimer's disease, and whilst that link is unproven, it is an interesting conjecture.
Do we now know everything about malt?
Perhaps malt still has some secrets?
Whatever is discovered, maltsters already have a message to deliver on the importance of malt, and that it started serving mankind before the pyramids were built.