Malting

Malting is the process of allowing the grain to start to germinate & sprout, so that it will generate enzymes (amylase) to convert its store of non-fermentable starch to a sugar.

If there are no enzymes present, the yeast will not be able to use the starch - it must first be converted into sugars.

Not all the grains in each recipe require malting. As long as some (at least 20%) have been malted, there should be sufficient enzymes (amylase) present to convert the starch in the other grains. Note: this is why you can add amalyse (Speedase? - commercial name ) to help speed/complete malt and grain beers & worts, but it won't do a thing for thin sugar based worts (no starch to convert).

Jack advises ..
    Malting for home use is not a difficult procedure, but it should NOT be attempted with oats or with rye.

    These grains, when malting, tend to attract butryfying bacteria - these organisms, by themselves are poisonous, and so is the butanol isomers that these bacteria produce (see page 127 (for oats) and page 130 (for rye) in the book "The Homebrewer's Garden" by Joe Fisher and Dennis Fisher, Published in 1998 by Storey Books (www.storey.com)).

    If you have a need for a malt of either of these grains - purchase it ready made rather than poisoning yourself with the homemade type.

    If you want a good rye flavor that can add a bit of flavor to a vodka, you would be better off using flaked rye or ground rye from a feed store that you boil for 30 minutes, to gelatinize the starch, then cool down to 155F before adding 10% by weight of six-row malt. I've tried it both ways, the malted rye tastes alot like malted barley when run up to 90%abv- the spicey/creamy flavors from the rye totally vanish- you might as well be working with barley malt syrup for all the rye flavor you get. When made with flaked (or boiled) rye and a little 6-row is added, the rye "heaviness" tends to come through a lot better, and makes for a more interesting spirit, vodka or whiskey.

I haven't done the following, as malted grains can normally be bought from beer-homebrew shops. Check beer related homepages for more details; I've summarised the following steps from a couple of books.
  • Soak grain for 24 hours, change the water, and soak for another day. Toss away any thing that float. Try to keep the water between 17-30 C; too cold and the grains won't grow.
  • Spread grain out (2-5 cm deep) on a wet surface, and keep at 17-30 °C, until it sprouts (7-10 days). Turn grain over daily & keep moist, so that all get a chance to sprout. Wait until sprouts/rootlets are 5 mm long.
  • Dry the grain - either spread out real thin in front of a breeze, or oven dry SLOWLY. Don't exceed 50 C until grain is dry (couple of hours), then 55 C for an hour, then 66 C for an hour. If it gets too hot, the enzymes present will be destroyed, and not work during mashing.
  • Clean and de-sprout the grains - place in a sack/bag and bang against a hard surface to knock off rootlets. Shake & toss in a sieve to allow crap to fall through holes.
Drying the grain isn't always necessary if you're going to be using it all straight away. Ted advises ..
    There is no reason that you must dry your malt before mashing. My grand father would soak bags of corn until it sprouted and then grind it up and mash with it. The reason brewers dry the malt is to remove DMS from the grains, this isn't necessary for distillation but it is always better to have a clean smelling ferment for the peace of mind that it gives.
Jack gives his method for malting ...
    Malting is easy -
    • Soak the grain for 72 hours (change the water every 24 hours) while soaking put an aquarium pump/airstone in the water so it bubbles through the bed of grain (it should have a good few inches of water over the top of the grain).
    • After the soak, put the grain in a bucket with hundreds of little holes drilled in it, then sit this bucket into another bucket that has a couple of inches of water in it. Put the airstone from the air pump into the bottom bucket so it bubbles up through the water- leave the lid on loose so the air can be exchanged by the pump. The air pump is scrubbing out the CO2, preventing mold growth, and preventing heat buildup.
    • Once the rootlets are roughly the length of the grain (for barley- for corn, wait until the root is about 2" long), dry the malt- this must be done in the dark - a food dehydrator is best.
    • You can also use the malt without drying it- this is called "green malt" just make sure the original weight of the grain is recorded to make recipe formulation easy.

      It's a pain to get it to grind when it's wet, though. It will have a higher enzymic activity - but not noticably. The real problem is that green malt (if you are making a malt whiskey) can give a funny flavor to the spirit. If the wet malt is only used for it's enzymic ability (ie. Bourbon) then it won't make a difference - use it wet in that case.

      Drying is complete when the malt weighs the same as the original amount of grain you started with.

    This system (using 5 gallon buckets) works best with 5 pound amounts at a time (starting weight).

    To make Scotch, just put the malt in a commercial bar-b-que smoker and smoke the grain dry (using the coolest heat possible), but use peat from the garden store as your fuel/smoking agent. Baled peat can be had for about $16US for 4 cubic feet at most big garden stores- just make sure there is no fertilizer in them (read the label). That's all there is to it.
Jack offers more help on How to peat your malt
    Right, some people on the distillers' group asked for help with Scotch- now I find out "I can't get peated malt in Austrailia"- fine- here's how to do it at home

    You can peat either barley you have malted your self or malt purchased from the homebrew shop: If it's home malted, then just take the freshly sprouted grains and dry them for 24 hours in the lowest setting of your oven (they should be half-dry at this point), for purchased malt, buy some 2-row from the homebrew shop and soak it for 24 hours in cold water, the grain is now ready to smoke. Soak the peat (from a garden store- a 4 cubic foot bale costs $15US) overnight in water. Prepare a bed of coals in the normal manner in a standard bar-b-que grill, or set your gas grill to low/medium. Drain the water off of the peatand place it in an even layer over the hot coals/burner. Put the grain on a clean, fine-mesh screen over the fire/peat bed. Cover the grill (with the vents wide open) to get the smoke in solid contact with the grain. Stir the grain every 5 minutes to prevent burning/scorching. Smoke the grain from 15 to 40 minutes until the grain is fully dry. When it's cool, it's ready for use.

    Update ! I just got through talking with someone at the Hugh Baird malting company- this is what I found out: By soaking some basic 2-row malt in water until you get a 28% moisture level, and then dring the malt with an open (low) peat fire, you can make your own peated malt. No need to mess about with smokers or charcoal grill. i.e.:
    • soak 1,000 grams of 2-row in water (unmilled, from the homebrew shop), until it weighs 1,280 grams (when the excess water is allowed to drain off).
    • Take this grain and place it on a tight-mesh screen, like metal window screen, and then put another layer of screen over the top of the grain, to prevent ash from falling onto the grain, which would cause a creosote like flavor in the malt.
    • Start a small fire under the screen with a bit of peat from the garden store.
    • Dry the malt over the fire slowly to prevent the malt from browning/charring- misting the fire and the grain with a water spritzer helps.
    • When the grain is back down to weighing 1,000 grams- you're done- you now have peated malt.
    • Mix it 50/50 with some unpeated 2-row, and brew an all-grain malt batch.
    • Ferment and distill it however you like- if it is too heavy in peat for your taste, just make a batch of straight 2-row malt whiskey, and blend however you like.


    I also finished an experiment in Scotch moonshine- "peatreek". Soaking a pound of commercial or homemade peated malt in a gallon of water at 155F for 40 minutes, straining out the grain (and rinsing with a cup or two of 155F water), then bringing the water to a boil and adding two pounds of table sugar, makes a nice, but one-dimensional Scotch. No nutrients are needed- the one pound of grain provides enough free amino- nitrogen to get a healthy ferment for that much sugar. It has a nice smokey flavor, with no real malt to back it up. It's nice in cocktails and the like, on it's own, it tastes like a bottom- shelf, bargain basement blended whisky- with better wood aging, a dash of sherry, a dried apricot or two, and it could compare nicely to the essence based Scotches made out of sugar spirit/vodka.
For more on malting, see :
Chris' Excellent Home Floor Malting Adventure
Malting
Malting Equipment
Malting process in a nutshell

Ian Wisniewski (whisky and spirits writer, and author of Classic Malt Whisky (Prion Books)) wrote about malting at Whisky World (big thanks to Whisky World for letting me copy these extracts !)
    Malting comprises three essential stages: steeping, germination and kilning, which provides the distiller with direct access to the grain's starch content. Starch is present within the endosperm (the main interior section) and serves as a food source, enabling the grain to produce the energy required to develop roots and an acrospire (shoot). The starch is initially enclosed within protein-lined cell walls, which the embryo begins to break down as it grows, in order to utilise the starch. Once the starch has been liberated, further growth is arrested by kilning (applying heat), otherwise a lower starch level would reduce the yield of alcohol.

    Steeping effectively 'awakens' the barley by hydrating the grains in steeps (vessels), with up to three separate batches of water raising the moisture level from around 12 per cent to 40 to 45 per cent. Simultaneously, 'pressure aeration' can be applied, which means blowing compressed air from the base of the vessel. This aeration is assertive enough to move barley from different levels of a steeping vessel, but gentle enough not to cause any damage; some movement promotes more consistent growth. Otherwise, barley remaining at the bottom of a steep would receive less oxygen during what is termed an 'air rest', diminishing the growth rate.

    Draining the steeps in between each batch of water gives the grain an air rest of several hours, or longer. During this period 'suction aeration' can also be used to introduce fresh air into the steep, while carbon dioxide is removed to ensure even growth.

    Air rests may seem to extend the timetable, though grain left continually underwater can actually take around twice as long to process. Air rests provide more oxygen which raises energy levels, and makes it easier for the grain to absorb water. This explains why the uptake of water is far more rapid after the first air rest, once the grain is 'energised'. Moreover, the micropyle (opening) at the tip of the grain is the most efficient conduit for taking in water, whereas the outer layers of the grain are relatively waterproof (and water uptake through these outer layers is slow).

    The water used for steeping at Port Ellen Maltings on Islay is piped direct from Leorin Loch in the nearby hills. A seasonal adjustment involves heating the water to between 13.5 and 14.5°C from mid-September to late May. Otherwise, adding colder water would simply prolong the time required to initiate germination, and enforce longer air rests. Moreover, as grain generates heat during steeping, adding a subsequent batch of water at a cold temperature would instigate thermal shock (grains loathe abrupt temperature changes).

    Visible confirmation that the grain is responding to its wake up call is the appearance of a 'chit', a small white root tip at one end of the grain. Diastase also begins to form, and continues to develop during germination (this combination of enzymes subsequently starts to break down proteins and starch in the barley, making them soluble, which is essential for the conversion of starch into sugar during mashing).

    Barley can be germinated either spread evenly across stone or concrete malting floors, or in germination vessels such as drums. On a malting floor this may take five days in summer, seven in winter, reflecting the ambient temperature. The barley is aerated by 'turning' (redistributing) it every few hours using a 'malt shiel' (spade), which helps control the temperature and rate of germination. Alternative options are a 'plough' (a three-pronged rake) or a type of rotivator, supplemented by another basic form of temperature control, either opening or closing windows.

    The germination drums at Port Ellen Maltings are not only the UK's largest, but also have the ultimate pedigree of being manufactured by the firm of Robert Boby. Each of seven steel drums holds the contents of two steeps (i.e. 50 tons of barley at original weight, 65 tonnes after steeping).

    Loading the grain into drums inevitably results in two separate piles of grain. As this would foster uneven growth rates in different sections of each pile, the drum is rotated twice. This procedure is assisted by angled fins bearing a corkscrew pattern set within the drum ensuring the grain spreads evenly across the floor.

    A perforated steel floor enables carefully controlled volumes of air, generated by large fans, to be blown through the grain. This maintains the appropriate temperature, and as the air is humidified with fresh water it also promotes the right humidity for growth (ordinary air would simply dry the barley too soon).

    The air flow, humidity and temperature are adjustable in order to control the growth rate, with the temperature not exceeding 25 to 26°C. Too high a temperature entails a risk of the embryo dying and damaging the enzymes. Another factor promoting consistent growth rates is that the circulating air also removes heat and carbon dioxide from the drum (exiting through vents). Continued growth sees the grain beginning to break down the cell walls and protein lining to access the starch. Meanwhile, developing rootlets also consume protein, which is another advantage. Protein must be carefully managed in order to avoid problems at subsequent stages in the production process. Higher levels of protein diminish the effect of hot water on the starch during mashing, for example, which compromises the rate of conversion into sugar. Protein can also burn onto the surface of the wash still, contributing undesirable caramelised flavours to the new make spirit.

    However, if rootlets were left alone to do what comes naturally, they would intertwine and create a dreadful tangle. This is countered by rotating the germination drums every eight hours, a leisurely turn lasting five minutes at Port Ellen Maltings, with the fins gently teasing the roots apart.

    After about five days the grain reaches an optimum stage of growth when most of the protein has been utilised for root growth, and the cell walls have been broken down, providing direct access to the starch. The acrospire (shoot) also extends under the skin (husk), along around three-quarters of the grain's spine. Any longer would indicate excessive growth. Any shorter, and it's not quite ready.

    A traditional method of checking growth was for the Maltman to inscribe his initials on a spade using a grain. If legible, the malt was ready. Another low-tech option is the 'rub test'. By splitting a grain open with a fingernail, a small amount of the endosperm can be rubbed between the thumb and forefinger. If this leaves a fine white powder mark, it confirms that the starch (in the form of barley flour) is ready for kilning. A lack of white powder indicates the starch is still enclosed by cell walls and protein.

    The aim of kilning is to arrest growth by drying the malt as quickly and uniformly as possible, with the moisture level typically 40 to 50 per cent at the beginning of the process. Taking care not to damage the heat-sensitive enzymes, the initial temperature is around 40 to 50°C. Once the grain reaches the 'break point', when the surface moisture has been driven off, the temperature is gradually increased to around 75°C.

    For malt that is being peated, an important factor is that moisture promotes the absorption of smoke, essentially by the husk. As the surface begins to dry, it becomes harder for the grain to absorb smoke, until reaching the 'break point'.

    Once the peating has been concluded, kilning dries the malt further (essentially the interior of the grains) to a moisture level of about 4.5 to 5 per cent. This can take from 25 to 40 hours, using either hot air or firing the kiln with gas or fuel oil. In addition to peaty, smoky flavours created by peating, kilning also develops the malt's flavour profile with a range of sweeter, biscuity notes.

    After the rootlets have been removed, malt is subsequently rested in sealed bins for several weeks. As the heat of kilning concentrates residual moisture in the centre of the grain, the resting period allows this moisture gradually to extend back and be evenly distributed throughout the grain. This ensures milling is more even, promoting fermentability and consistency.

    The rootlets aren't wasted either, serving farmers rather than distillers. Mixed with dust from incoming barley to form 'malt residuals,' then dampened with water and shaped into pellets, this is used as cattle feed. Islay cows are used to the peaty flavour that their local 'take-away' serves up, whereas mainland cows are not. However, Port Ellen Maltings also caters for them by adding a small amount of molasses to the recipe, which sweetens the flavour.
How much peated malt to use ? Jack writes ...
    if you get the same malt that I do (from Hugh Baird malting company), it comes in 3 strengths of peat: low (5ppm), medium(10ppm), and high(15ppm). This means that you CANNOT make a heavily peated malt like Ardbeg, Lagavulin, or Laphroaig- they are in the 40 to 50ppm phenol content range. You can come close to Bowmore (20ppm). And Aberlour, Glenfarclas and Cragganmore are easy to do - they have peat/phenol content of 2ppm. Deanston and Glengoyne have no peat at all.

    To make a Scotch, just make an all grain batch of beer using peated barley, either straight (most homebrew shops, like mine, only have the heavily peated malt in stock), or mixed in with some domestic 2-row to cut the peat levels. I'm an Irish lover, mostly- so I make mine unpeated, and I use the corn whiskey books' tips on "making the cut" to make the smoothest stuff you could ever find on the planet. I've made Scotch by mixing 2-row and peated barley in a 50/50 mix and double potstilling it. It was great when aged on sherry wood- but I gave it to a family member who likes Scotch more than I do.... (by the way, mixing unpeated malt whiskey with corn whiskey (80%malt/20%corn) and aging on old bourbon chips with a dash of sherry makes a great copy of Bushmill's Black Bush Irish blend- my favorite.)
More from Jack ...
    After re-reading some of my books, I found some numbers that might help those looking to copy Glenmorangie Scotch. On your commercial stills photo page, Laphroig is listed as a 10 in peat, Glenmorangie is listed as either a 2 or 3. From another book, I found out that the ppm of phenols (from peat) in Laphroig whiskey are in the 40 to 50ppm range (the heaviest)- but I couldn't find anything on Glenmorangie. After comparing the numbers, I ran the estimates as given Laphroig= 40 to 50ppm which equals a rating of 10, and Glenmorangie is a rating 3 to 4, which gives X for the peat levels. Going from the highest to the lowest- I found these possible peat levels (in ppm of phenol) for Glenmorangie= 8,10,12,15ppm are all possible levels. Another published ppm level states that Bowmore is about 20ppm- medium peat- far too heavy for the likes of Glenmorangie, ruling out the 15ppm rating by tasting. I then found a Scotch retailer online listing his products- he has Glenmorangie listed as a "North Highland" type of Scotch- other retailers list it the same. The same book that lists the ppm of Laphroig and Bowmore states that The north highland style sits between the lightly-peated Speysides (like Aberlour and Glenfarclas at 2ppm) and the medium-peated Bowmore.

    The average of 2ppm and 20ppm is 11ppm- right between the mid-range numbers I calculated above for Glenmorangie "possibles". This, added to the fact that on Glenmorangie's OWN WEBSITE, they state that they take a middle cut of only one-fifth of the second run, to get a delicate, light Scotch. Comparing these cutoff points to the corn whiskey book, which takes a full 57.1% of the available alcohol as a middle cut, makes Glenmorangie an even tighter cut than the already smooth-as-water corn whiskey type of cut. Hugh-baird malting company sells three levels of peat malt: low (4-6ppm) which is of no use here. Medium (7-12ppm), which could be used as-is. and high (13-20ppm) which should be cut by about one-third with unpeated 2-row, in order to get about the same levels of peat as Glenmorangie, That is, enough to provide a complexity to the malt flavor, but not enough to make the whiskey taste like dirt.

    To sum up- find out what peat you can get from a brewshop, cut it with 2-row if you need to. Mash it, sparge it, cool it, then ferment it. Keep in mind that the water in the Glenmorangie distillery is considered "hard", but not as much as Burton water- I would leave it alone if I have good luck with all-grain beer already. After the ferment, Distill the stuff in a "beer stripping run" to collect about 1/3 of the original mash volume until you get enough to fill your spirit still (using a stovetop potstill in the 5gal range, with a one-gallon ice-water-wok evaporative still works very well in giving a light spirit on the second run). Put your "low wines" into the smaller still, and collect out only about the middle 20% of the run to save as drinking spirit. For example, mix 5 pounds of 2-row with 10 pounds of heavily peated brew-shop malt, mash and ferment as for allgrain beer with hard water. Distill out of this mash about 1.5 gallons (6L), run this into a small potstill, then collect out about 50ml of foreshots, 300 to 400ml as heads, approximately 500ml as your "keeping spirit", then save the rest as feints to be redistilled. Aging on ex-Bourbon wood, with a bit of finishing on ex-sherry wood completes the drink. This is not a cheap drink to replicate, but it is very good, and cheaper than $50US a bottle Glenmorangie.

    References:
    Spirits & Cocktails by Dave Broom (Carlton books, 1998)
    Making Pure Corn Whiskey by Ian Smiley (self-published, 1999)
    Classic Beer Style Series #8 Scotch Ale by Greg J. Noonan (Brewers' publication, 1993)
    Classic Beer Style Series #18 Smoked Beers by Ray Daniels and Geoffrey Larson (Brewers' publication, 2000)
    Malt Advocate Magazine, Volume 9, number 2, 2nd quarter, 2000 issue, Glenmorangie advertisement, pg3
    www.Glenmorangie.com- online distillery tour.
    homedistiller.org - Commercial distilleries photos and links page.
Ian Wisniewski (whisky and spirits writer, and author of Classic Malt Whisky (Prion Books)) wrote about peat at Whisky World (big thanks to Whisky World for letting me copy these extracts !)
    In addition to the level of peating, another consideration is the origin of the peat. As coastal and inland peat has differing characteristics, this yields a varying range of phenolic compounds — though exactly how influential this terroir is in the resulting dram depends on who you ask (particularly as the production process has a significant effect on the phenolic level). Peat cut from inland moors features a higher level of forestation and bracken, with Speyside peat for example comprising plenty of Scotch pine, roots, heather and spagnum moss (which has a great ability to retain water). The closer to the coast, the higher the level of sand, which means a looser texture, with coastal peat bogs, particularly on the west coast, also characterised by seaweed.

    Islay peat is a prime example, comprising pine trees, grasses, bog myrtle, heather and mosses, alongside a significant level of seaweed and sea spray influences, while sand contributes additional saltiness (being historic 'ocean sand'). These components combine to give a lightly oily peat with iodine, medicinal, salty and even tarry notes (which can be readily identified in Islay malts).

    Extracting peat is obviously eco-minded, only cutting the amount required for that year, with the surface layer of turf reserved and placed over a previously cut trench, ensuring regeneration. The peat cutting season, typically April to September, reflects entirely practical considerations as peat bogs must 'dry' to the point when they can be walked on (or take tractors, which have been known to disappear in peat bogs). Having worked a short shift on Islay, I know I would never be hired in that capacity. It's skilled and exacting work. The hours are awful too, a 4 to 6am start, finishing around 9 or 10 pm, as favourable weather means cutting as much as possible.

    Hand-cut peat is typically extracted from a trench in two stages, using a peat cutter (or peat spade) to cut a piece around 60cm long and 15cm wide. After cutting an initial surface layer, another cut is taken directly below, with each piece laid on adjacent turf to begin drying. Mechanised cutting entails pulling a machine behind a tractor, fitted with either a 'circular' or 'chain saw.' This cuts a line several centimetres wide, which can be adjusted to various depths, cutting between 0.5 and two meters (so it can be a shallower extraction than hand cutting).

    Different machines have individual methods of extruding peat, which can be compressed in a chamber, prior to evenly spaced bricks of peat around 10cm square being deposited in the machine's wake. Ready to dry where they fall, the pieces are collected a month or so later. Alternatively, peat can be continually squeezed out (like toothpaste) for the full length of the trench being worked. With a diameter of around 15cm, a skin forms on the surface within three or four hours as the peat begins to dry, preventing absorption of any rainfall. Continual shrinking, as the peat dries over the next couple of weeks, also breaks it up into manageable lengths, around 10 to 40cm long, with a diameter of five to 10cm.

    Hand-cut peat typically takes longer to dry, while also requiring an additional step. It takes about two weeks for a skin to form, enabling the peat to be handled and carefully stacked with several other pieces to form either a small tower or wigwam. The wet side (the one that lay on the turf) is placed outward to ensure even drying over the next four weeks or so. Judging the moisture level is down to the experience of the peat cutter, though it's obviously not an exact science. Consequently, peat arrives at the distillery with moisture levels that can vary from 10 to 45%, and balancing this range is part of the skill of peating.

    The aim of adding peat to a fire, which may even be started using redundant pieces of whisky casks, is to create a consistent level of smoke, not flames. As phenols are flammable, they can be destroyed by a flame breaking through onto the surface of the peat. Controlling the fire and peat reek entails various parameters. The more fibrous top layer of peat provides more smoke, but is more reluctant to burn than darker, underlying layers which produce more heat. Very dry peat gives plenty of heat but not enough smoke, and so not much of that distinctive flavour. Adding smaller blocks of drier peat and crumbly debris — known as 'caff' or 'peat fines' — can help impede air flow and so produce more smoke. This type of peat can also be hosed (being very dry it holds water well) and used in its rehydrated form to help cool the fire down (being careful of course not to extinguish it) and promote smoke. To maximise the influence of the smoke, which at a traditional floor malting ascends through a wire mesh floor on which the malt is spread out, mechanical turners and fans are used to help draw the smoke through more evenly. Historically malt was turned manually on the wire floor by distillery employees. As one of the distillery's least popular jobs, it was at usually rewarded by a dram.

    Peating times vary from around 16 to 24 hours. This reflects the moisture level of the malt, typically 40 to 50% at the beginning of the process, with moisture promoting the absorption of smoke, essentially by the husk. As the surface of the malt begins to dry, it becomes harder to absorb smoke, until reaching the break point when the surface moisture has been driven off. Once peating is concluded, the malt (essentially the interior of the grains) needs further drying to a moisture level of around 4.5 to 5%. This entails kilning, with the kiln fired by various types of fuel, such as coke, or by using hot air, with kilning taking around 25 to 40 hours.

    Malt is subsequently rested in sealed bins for several weeks, which is an important procedure. As the heat of kilning pushes remaining moisture to the edges of the grain, the resting period allows this moisture to gradually extend back, and be evenly distributed throughout the grains. This ensures that milling is more even, promoting fermentability and consistency. Peating levels are measured as phenolic parts per million, with a lightly peated malt around one to 10 ppm, a medium level around 10 to 30 ppm, and 30 to 50 ppm for a heavily peated malt. Commercial maltsters, which can do the job at a far more competitive price than in-house floor maltings, originated in the 19th century, but really took off in the late 1950s to early 1960s. That's when many distilleries increased their production capacity, but without extending malting floors. This meant maltings could not keep up with new production levels and numerous distilleries closed their malting floors. The minority retaining them include distinctive drams Bowmore, The Balvenie, Highland Park, Laphroaig and Springbank.

    Whoever peats the malt a similar degree of accuracy applies, with peating levels generally between three to five ppm either way of a distiller's specifications, a range which is not significant enough to cause any concern over consistency of the new make spirit (distillers inevitably prefer the peating level slightly over rather than under). Specific peating levels can also be attained by combining peated with unpeated (or lightly peated) malt, a practise known as blending.

    The peating level within the malt decreases during the production process. Although this varies among distilleries, a typical reduction of 10 to 40% could apply to the new make spirit. The largest degree of loss is typically attributed to distillation, with feints, pot ale and spent lees carrying a significant level of phenols.

    During maturation the peating level can also affect the influence of the cask. This is usually said to account for up to 60 or 70% of a malt's resulting flavour, though it's more like 40 or 50% with heavily peated malts, as phenols mask the oak influence.

    The type of cask is another consideration. Bourbon barrels promote phenols and distillery character more readily than the richer flavour profile and sweetness of a sherry barrel, where phenols are either masked or more integrated, depending on your perspective.

    Peating levels do not seem to be affected during the first 20 years or so of maturation. The level can actually rise during this period, due to similar compounds, polyphenols, released by the barrel's toasted / charred layer. While the visible longevity of phenols varies among malts, one theory is phenols begin fading after 20 years. Another opinion is that the phenol level remains constant, and as other flavours derived from the oak become more pronounced, phenols are masked. My current opinion is that I need to do a lot more tasting, then I'll see how I feel …
Note that "live" malt is NOT the same as just "liquid malt" commonly bought in a can from your homebrew shop. If you are using it with grains, you need a malt that still has the enzymes present & active in it. They will not be present if it has been heated up over 70 ish degrees. Harry explains ...
    There are two broad types of malt extract. Brewers (non-diastatic) and Bakers (high-diastatic). I've been a baker since 1969 and we always used malt in the old days to convert some of the starch for yeast food. I guess what I'm saying is that if you used bakers malt instead of brewers malt, you would achieve a result, and probably cheaper too.

    Have a look at this site in U.S. http://www.maltproducts.com/

    This extract from their products page...

    Malt, the Natural Flavor, Sweetener, and Coloring Agent is available in many forms.

    Liquid, Dry, Diastatic, Non-Diastatic, Dark, Light, Extracts, Syrups and Powders with Cereal Adjuncts.

    Diastatic Malts (with the natural barley enzymes still active). are used primarily by bakers to supplement the amylase in the wheat flour to provide sugar for fermentation, improve pan flow, improve crumb color and break and shred in bread type products.

    Nondiastatic Malts (without active enzymes), are used as flavoring agents, for color sweetness and humectancy. The nutritive materials present promote vigorous yeast activity, accelerate dough conditioning and add flavor and aroma to finished baked products.
So... if you are trying to convert other grains, make sure that the malt you use is "diastatic", or else you will need another source of the enzymes. If you simply want a malt for use on its own (ie as a quick and simple whisky base), then the "non diastatic" is ok.

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