C14 - Finishing - completed Flashcards
can sake be packed and sell immediately after filtration?
yes, some are sold in limited numbers as a seasonal product
why most of the sake needs to go through the finishing processes?
- clarity
- colour
- alcohol level
- stability
what are the processes in finishing?
- subtracting
- pasteurisation
- storage and maturation
- additions
what is not allowed to remove in finsihing?
alcohol
for all sake, what is the only ingredient permitted to add after filtration?
water
what are the techniques used in subtracting?
- sedimentation
- protein fining
- charcoal fining
- final filtration
what sedimentation does?
- after filtration, leaving the sake for up to a week to settle the sediments (small particles of rice or yeast)
- clear sake can be pumped off the sediment
- using a filter to filter out the sediments
what protein fining does?
- during storage, tiny protein particles suspend in the sake
- adding fining agent can make these particles to clump together
- and then filter out those larger particles
what is the functions of using active charcoal in charcoal fining?
- it’s an fining agent to reduce colour
- remove undesirable aromas, flavours, textures
- slow down sake ageing
- slow down the development of colour and aged aromas
what is the Japanese term of charcoal fining?
roka
when was the charcoal fining technique developed?
1911 - 1923
when was clear sake most appreciated?
when the water-white style of Niigata style is developed in the late 1980s
Why is the market trend is toward muroka style now?
- brewers believed roka also removed some positive characters
- roka makes the sake too thin and characterless
- in extreme cases, can even smell and taste the carbon
- muroka is more natural, richer and less manipulated style
what are the 2 main objectives of using filters in final filtration?
- produce a crystal clear sake
- remove yeast and bacteria for stability
why pasteurisation is needed?
- risk of deteriorating
- koji enzymes can continue breaking up starch fragment
- if temperature rises, yeast and microorganisms can feed on the residual sugar
- low acidity environment can let microorganism lives
- cannot add SO2 as preservatives because it won’t work on low acidity environemnt
which tool can be used to remove yeast and much more smaller bacteria?
special filters with very small pore size
what is hi-ochi kin?
a strain lactic acid bacteria
what is the problem of hi-ochi kin?
it can make the sake cloudy, oxidised and give unpleasant odour
what is not being removed by normal filtration?
koji enzymes
what is the problem of the remaining koji enzymes after filtration?
- increase sweetness
- accelerate oxidation
- loss of freshness
which tools can be used to remove the remaining koji enzymes?
- molecular filter
- heat
what kind of special sake can be produced by using molecular filter?
unpasteurised sakes that do not need to be kept cold
what is the disadvantage of molecular filter?
expensive
what are the effects of using heat for pasteurisation?
- deactivate koji enzymes
- kill any yeast and bacteria
what is the temperature range for pasteurisation?
60 - 65C
what are the two method of pasteurisation?
- pasteurise in bulk
- pasteurise bottled sake in hot water
what is the other name of bulk pasteurisation?
ja-kan
describe the ja-kan method
- the coiled tubes are heated up to 60 - 65C
- sake runs through the tubes to pasteurise
- then the sake is transferred to a large tank for storage
- usually will go through once again for second pasteurisation
what are the advantages of using ja-kan method?
- very efficient for large quantity
- sterilising and stabling the sake very well
what is the disadvantage of using the ja-kan method for ginjo sake?
- harm the ginjo aromas and freshness
how long it take to cool down the pasteurised sake after ja-kan?
2 days
what are the Japanese names for bottle pasteurisation?
- bin hi-ire
- bin-kan
describe bottle pasteurisation (bin hi-ire)
- bottled sakes are put into hot water till to raise to the required temperature
- bottles are cooled down by showering cold water or put into ice-cold water
- some let the bottles cool down naturally by the cold ambient temperature
- can be done by hand or machine
what is the advantage of using bin-ire?
- it’s already bottled, no need to pasteurise the second time
- quick and gentle
- the shortest time
- usually used for ginjo styles, as well as others
what are the characteristics of nama-zake?
- extremely fresh
- expressive taste
- lingering finish
when to release nama-zake, traditionally?
- right after the first press
- around mid-November to early December
how the nama-zake are labelled?
Seishu (new sake)
how long will the nama-zake be available?
till early summer
why nama-zake only available for a short period of time?
- it’s more sensitive to heat and maturation
- risk of spoilage by hi-ochi bacteria
what causes nama-hine-ka?
- over-maturation
- incorrect storage conditions
- enzymatic action cause degradation of nama-zake
what is nama-hine-ka smells like?
- malt, bacon, rancid cheese
other than the ‘true’ nama-zake, what are the 3 options to maximise freshness of the sake?
- nama-chozo
- nama-zume
- ‘once-pasteurised’
Nama-chozo is sake pasteurised at which stage?
once, after bulk storage
why nama-chozo only pasteurised once?
- provide some of the character of ‘true’ nama-zake
- slightly lower risk caused by poor storage in the supply chain
Is nama-chozo a legally defined term?
yes
Nama-zume is sake pasteurised at which stage?
once, before bulk storage
what is hiya-oroshi?
name-zume released in autumn
what is ‘once-pasteurised’?
- sake is pasteurized once before storage in bottle
what is the advantage of ‘once-pasteurised’?
- the second pasteurisation is unnecessary because the sake is already bottled
- it keeps the sake fresh, stable and unmanipulated
why sake needs to be rest for 6 - 12 months?
- heat in pasteurisation alters the aromas, with an unrefined taste
- freshly filtered sake is rough and lively in flavour
- resting can settle and balance the flavours
which period in a year the sake is stored for resting?
during spring and summer
what is the temperature range for resting the sake?
- vary
- from freezing to ambient
- normal is 10 - 20C
what kind of vessels are the sake stored before release?
- sealed tanks
- bottles (ginjo)
what is the legal rule for koshu’s minimum maturation length?
none
brewers tend to mature koshu for how long?
two years or more
why water addition is sometimes necessary?
- the sake in storage is usually 17 - 20% abv, too high for consumption
- adding water can lower the alcohol level by 1 - 2% abv
what is the characteristics of genshu?
- more concentrated and rich flavours
- higher alcohol
why the brewer wants to blend the sake?
- for volume
- for stylistic consistency
what are the components the brewer can use for blending?
- polishing ratios
- rice types
- yeast types
- fractions
- ages
- storage methods
- amount of sake lees
how to determine the sake grade is different polishing ratios are blended in the sake?
the highest polishing ratio limits the sake grade
what are the common colours of the sake bottles?
black, brown or dark green
