W4 - L1 - Malting Barley Flashcards
A 2 stage ‘industrial’ process
- BARLEY is malted to produce MALT
- MALT is brewed / distilled to produce BEER / SPIRITS
Malting Barley : Quality Criteria (7)
- High germination
- Homogeneous (uniform) sample, low screenings
- Moisture content < 21.5% at harvest
- No mechanical damage / splitting / skinning (2%)
- Good colour / no moulds
- No heat damage
- Moderate grain nitrogen content (Protein %
what is the moisture content of Malting Barley at harvest
<21.5%
what sort of matting varieties have a high capacity for
good malting varieties have high capacity for beta glucanase activity
what are cell walls made of
beta-glucans
what does beta glucanase (enzymes) ensure?
rapid breakdown of cell walls thus, ensuring an increase in speed of
starch modification
Chemical basis for the malting process (2)
- normal germination - starch is converted to reducing sugars which are used to nurture embryo
- In malting process the aim is to control this process - with partial starch change or modification
what is normal germination
starch is converted to reducing sugars which are used to nurture embryo
what is the aim in malting process
the aim is to control this process - with partial starch change or modification
how many stages are there to go from barley to malt (the malting process)
name them
3
- steeping
- germination
- drying
The malting process
- Steeping
moisture content raised to 46%
(this may include rest periods in air only) - this process takes up to 3 days
in the steeping stage of malting process what % does moisture content rise to
46%
how long does the steeping stage take
3 days
The malting process
2. Germination
temperature : 14-17 celcius
the grain is turned regularly - matting and the process takes 4-5 days
The malting process
3. Drying
arrests starch conversion, the ‘malt’
is dried down to 2-4.5%, gives flavour and colour to malt
Trial Research Studies – UCD Boortmalt Experimental Scale : Micro-malting
- 500g of individual reps malted in Jo-White micro malting unit
- Analysed to commercial distilling malt specification (IOB, 1997) in laboratory of Boortmalt / Antwerp
- Key focus on: Soluble extract, fermentable extract, spirit yield, SNR, friability plus others
steps from Malt to Beer (8)
- malt is stored for a month
- milled
- mixed with unmalted grain
- mashed ——> wort
- wort is boiled
- hops added
- cooled
- yeast added ——> Fermentation –> Beer
during the process of malt to beer why is the wort boiled
- stabilisation
- remove bad flavours
The Malting and Brewing Process
Slide 10 & 11
what sort of weather is needed for malting barley production
- Suitable weather – cool bright moist – Not too dry, not too wet, not hot
what sort of soil is needed for malting barley production
suitable soil types :
– free-draining with low soil nitrogen levels
– key geographical areas in Ireland
South Kildare, Carlow, Laois, Wexford, East Cork
also areas of Tipperary, Offaly, Donegal, Louth
- medium to light land
– brown earth soil types
Malting Barley Production
- early-sowing dates : February-March
- Even uniform crops with good crop structure
- Good crop husbandry - disease control etc
- Detailed Nitrogen fertilisation programme– N applied earlier and in modest amounts
- Key 2022 cultivars are Planet, Laureate,- Also Barley for roasting (brewing process)
what are wet weather diseases in Barley(4)
Wet weather diseases
- Rhyncosporium
- Net blotch
- Ramularia (leaf spotting)
- Fusarium species on the ear Sooty moulds / Botyritis
dry weather diseases of Barley (2)
- mildew
- Rust diseases
what is grain protein in malting barley
a key quality parameter
what level of grain N% (PROTEIN) is needed
low to moderate
what sort of malt does a high protein barley produce
poor quality malt
– negative relationship between protein and starch
– low starch reduces the extract in the malt
can protein levels be too low
protein levels can be too low
– protein levels are correlated with enzyme levels
what is the key % protein for barley for brewing
8.8-10.8%
what is the key % protein for barley for distilling
7.5 to 8.8 %
above and below what % of protein is barley rejected
above 10.8 % rejection **2018 ,
- problem with barley below 7.5 to 8% protein
Protein content in Malting Barley
in a COOL WET season
- low barley protein levels
- Average’s in the range 9.0 to 9.4% protein
– The average figures in the last decade were 10 -
what is the reason for Average’s in the range 9.0 to 9.4% protein for malting barley COOL WET SEASON(4)
– Cool wet season with high summer rainfall
– Early sowing dates / N appl. dates
– Restrictions on N use / N directive / REPS
– Rotation changes – demise of sugar beet
Protein content in Malting Barley in 2018 – HOT DRY summer
- very high barley protein levels
- Average’s in the range 11 to 13 % protein
– The average figures in the last decade were 9 – 1
reasons for high barley protein levels in HOT DRY weather (3)
- Lower yields
- Late season soil N uptake
- Nitrogen translocation to the grain is higher
with higher summer temperatures
over what % screening is not acceptable
over 8%
Malting Barley : % Screenings
table 21
at what % screening is the base price (€/t)
3.1 to 4.0 %
what is the protein % for Malting barley quality requirements for brewing
Protein: 8.8 – 10.5%
what is the extract (sugar) % in malt
81-83%
Malting barley quality requirements for brewing:
High enzyme potential (3)
- High enzyme potential:
– to ensure optimal protein degradation
– to ensure adequate sugar degradation
– to ensure the extract level
what do plump kernels add to malting barley
more sugars
what doe even size kernels add to malting barley for brewing
homogenous malting
what effect has string husks on maling barley for brewing
improve brewing process
what are brewers looking for
Brewers are looking for a balance between the amount of alcohol (translated in starch content in the grain) and flavour (the amount of protein in the grain)
if protein content is very low what does this influence
negatively influence the enzyme potential.
what are distillers looking for in malting barley
Distillers are looking for low
protein barley with as high
extract as possible as this is
positively correlated with high
levels of alcohol yield.
what is the alcohol yield potential of malt measured through
PSY
(predicted spirit yield) formula.
what is the minimum amount of litres per tonne of pure spirit extracted from the malt or it will
be unacceptable to distillers
405 litres
Malting Barley Trials -Teagasc Oakpark
Effect of Sowing Date on Yield and Quality
graph slide 25
the earlier the sowing date - the higher the yield (March)
the later the sowing date (late april) - higher % Grain N
