Irish Whiskey 

Raw Materials 

Unmalted barley 

  • Malted barley tax was imposed in the middle of the 19th century. Distillers started to use unmalted barley as a way to reduce their tax bill.

  • Gives higher alcohol yields than malted barley as more starch is present

  • IDL use a minimum of 20% in their mash bill, up to 60%

  • Gives a spicy and fruiter flavour with an oily mouthfeel.

Malted Barley 

  • For enzymes 

  • Bushmills produces only Malt whiskeys

  • Gives a biscuity sweetness 

Wheat - Corn - Rye 

  • Grain whiskey

Processing the Raw Materials 

Malting (barley) 

  • Grain starts to germinate artificially by creating ideals levels of moisture and temperature. 

  • For 2-3 days the barley is placed into water, then stepped, then drained. 

  • The moisture level is raised to the level needed for germination w/o drowning.

  • When the barley starts to grow it is called GREEN MALT.

  • Green malt must not dry out and the temperature has to be controlled. Too high (kill and stop germination)

  • Whilst the grains are modifying the starches into soluble sugar the grains are constantly turned to avoids roots knotting together.

  • Green malt (once modification is complete) is placed into a kiln.

  • Kiln > heated and dried to stop germination w/o damaging the enzymes.

  • At this point peat can be introduced. Peat will be used as fuel. As peat burns it gives off a perfumed smoke that is rich in flavour compounds(phenolics). For the peat to impart a flavour the temperature of the kiln must not be too hot, lowering the temperature of the kiln will have a greater effect.

  • The level of peat can is measured in PPM, after distillation the PPM will have dropped  by 2 thirds.

  • Peated malt in whisky - aromas of smoke, tar and seaweed.

  • No whisky is made using only peated malt.

  • Almost all distilleries buy in malt tailor made to their desired style.

Corn and What 

  • NOT malted, instead cooked.

  • Cooked in a pressure cooker at high approx. 144c in order to hydrolyse the starch allowing the starch to become soluble in water.

  • Malted barley (10% of mash bill) is added to the wort for its enzymes and is able to convert all of the starch into sugar.

Image below - malted barley with visible sprouts

IDL(Irish distilleries limited) Midleton in Co. Cork 

IDL has a dominant market postion, its style has become synonymous with Irish whiskey as a whole.

  • Triple distilled 

  • Unpeated 

  • Often w/ unmalted barley


Law > distilled to a strength less than 94.8%

  • Triple Pot Distillation 

  • 1st distillation takes place in a wash still to produce "low wines" with a strength of between 22 and 50%abv

  • The low wines are redistilled in the feints still to a strength of between 50 and 78%abv

  • This distillate is split into heads, hearts and tails. 

  • Heads + tails = weak feints > are redistilled with the low wines in the feint still

  • Heart = strong feints, is sent to the spirit still for the 3rd distillation

  • This distillate is also divided into heads, hearts and tails.

  • Heads + tails this time are redistilled with the strong feints (heart)

  • Heart is collected for the new make spirit

Triple distillation is a more selective process than double distillation. It producers a lighter flavoured spirit compared with other pot still spirits. 

The wash still are equipped with small rectifying columns, they can be bypassed to help promote reflux. These spirits are the backbone for blends such as Jameson.

Column Distillation 

  • Grain whiskey, typically have a higher % of corn in the mash bill


3 column still > Produces a particularly light spirit

  • rectifying column

  • hydroselector column > remove heavy alcohols

  • a final rectifying column

Double column still

  • Made up of an analyser and a rectifier

  • Low wines (1st distillation) produced in the wash still can be sent to the analyser

  • By linking the still in this way and varying the mash bill and the strength of the final spirit, this still is able to produce a range of light and fuller flavoured spirits.


Law > in wooden casks for a minimum of 3 years.


IDL - conducted considerable research into wood. From the 1970's imposed a new wood policy which involves the a greater use of bespoke first-fill european oak casks and first-fill American oak. 

Some new oak is used for Jameson Gold Reserve. This has resulted in premium blends having greater quality, weight sweetness and complexity.

Image below - 4 distillers to remember. Midleton, Bushmills, Cooley and Kilbeggan

Bushmills Distillery 

  • Located in Northern Ireland

  • Only producers malt whiskeys

  • Triple distilled following the Midelton temmplate to 84%abv

  • Wash is from 100% malted barley 

  • The 10 stills have tall slender necks that encourage reflux producing a spirit that is delicate, fruity and floral. 


  • Ex-bourbon and Tennesse Whiskey barrels > 200L heavily charred American oak

  • Bespoke Oloroso Sherry butts are also used

  • IDL (Midelton) supplies the grain whisky for Bushmills Original

Cooley Distillery 

  • Established 1987 

  • 2 pot stills and a 2-column continous still produce Irish whiskeys that are different from the others.

  • Pot still whiskeys - typically double distilled

  • One of their malt whiskey brand uses peated malt

  • Column still produce grain whiskey for blends

  • Irelands only single-grain whiskey made from corn

  • Cooley opened and run Kilbeggan

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