Grain Whisky Flashcards
grain distilling
continuous distillation
why cont dist?
-high rectification ( means to produce a pure ethanol conc)
production
derived from a mash containing approx 90% unmalted cereral
in case of the flow diagram, at an equal stage to malt whisky production. grain and neutral spirits are produced after fermentation and they are further processed into alternative spirits and then packaged to be traded.
grain whisky produced less characteristic whisky and is hence predominantly used for blends.
Grain vs Malt
Produced more ( that is because it acts as a base for many blends )
goes beyond only malted barley and uses other cooked , unmaled cereals like barley, maize, wheat
It is produced at approx 94.8 as compared to malt that stands at 69
also, has a low congener concentration as compared to the high congener concentration in the malt whisky.
Grain whisky vs GNS
85-90% grain | 100% grain
no exo enzymes| permitted
<94.8% abv| <96.8% abs
matured for at least 3 years ( grain whisky) and produced in accordance with the scotch whisky act | cannot be called scotch whisk and no mat.
whisky - GNS feedtsock for malt whiskies.
GNS - tight volatile epecifications ( mathanol, diacetyl etc. )
Distillation column.
consists of analyser and rectifier with plates. refer to diagram on board.
Every plate is 1.5 pot distillations - reason why it is so rectified and concentrated.
2 still (analyzer and rectifier)
American, candian, light rums - not purely restricetd to GNS or grain whisky.
Coumn distillation of Grain whisky
refer to flow diagram
GL
Gay lusac ( scale)
Theory of Continuous Distillation
- based on difference of volatality
- Units to be expressed in percentage of alcohol for excise and duty purposes
- The ethanol-water system graohs can be used from 0 to 97.2 % ethanol ( which is the azeotropic point ) A
- At this point the percentage of alcohol in vapour at atmospheric pressure is equal to that in the liquid.
At a temperature below the bubble point the two comp exist only as liquids and at temp above the dew point they both exist as vapours.
Sieve plates
- designed to collect low level of liq on plate area ( mostly 5cm)
- holes to be sufficiently small so that upward vapour velocity can be prevent weepage but sufficently lrge to prevent blockage ( holes 9-12mm)
In rectifier ( smaller holes)
coloumn design
- Weir
- down comer
- overflow cup
- Sieve plate
Weirs
- surrounds downcomers
- prevents vapour from flowing up the downcomers
- lcontrol level of liquid on the plate
factors to choose sieve plates
- cost
- solids?
- type of feedstock
- relative yield and efficiency
difference in running of beer still
whisky ( 30C, less therml degradation, 12-14 plates)
GNS ( 85C )
18-22 in stripping section , lower losses
Fuel alcohol ( 100C , max recovery of ethanol)
fuel alcohol isnt drunk , so max can be taken in.
Doubler
it’s like a second distillation.
after first distillation in the stripping coloumn
and get characteristics of a pot distillation using a doubler ( copper)
This removes acids and phenolics.
batch and cont.
prodyct at 67.5 - 70 % abv
Used in bourbon ( efficiency of stripping coloumn and characteristic of pot distillation)
Read thumper
Further processing
3 ways :
1. Pot still ( doubler in bourbon whiskies)
- Congener removal and alc conc by rectifier col/super rect coumn/aldehyde coloumn/extractive dist. column/purifying column.
- for congener conc
( fusel oil coumn and heads conc)
Coffey Still Ops
- pre-heat wash through rectifying coloumn ( this increases internal reflux)
- feed this into the top of an analyzer
- vapours from top of analyzer to bottom rectifier
- reflux from base of rectifier to top of analyser.
- product drom 5-10 plates above rectifying coloumn ( should be calculated )
Coffey Still Ops
- pre-heat wash through rectifying coloumn ( this increases internal reflux)
- feed this into the top of an analyzer
- vapours from top of analyzer to bottom rectifier
- reflux from base of rectifier to top of analyser.
- product drom 5-10 plates above rectifying coloumn ( should be calculated )
Changes in coffey still vapour comp
- different fusel oils from diff points based on volatility
- solubility in water and ethanol accordingly
tray number xyz will have more of abc
Fusel oil
from the fusel oil column it exits and reaches another coloum with water in it which makes the fusel oils to settle on the top of water. This top layer can be removed and
- put in bulk storage
- mixed with water and then made into sewer or refluxed back into the water container
Aldehyde removal
- undesirable for grain/GNS
- v reactive
- v volatile
- plate to remove it
- barbet still?
WHere is copper in all this/
- copper slippers
- throughout the stills
- for copper exposure
Barbet still
- why choose this alternative? for type of feed ( high foam? this removed co2)
- heads removal section over the analyser to remove some volatile comp beofre they reach they reach the rectifier
- high alcohol loses compared to coffey
- more used for rum
