Fermentabilty Flashcards
(28 cards)
What is the most important objective of mashing?
To obtain the required sugar spectrum
The sugar spectrum is key to fermentability.
What types of sugars can most yeasts used in commercial brewing ferment?
Mono, di and trisaccharides
What does a typical wort consist of in terms of fermentable sugars?
Around 75% fermentable by weight
What test is used to determine the fermentability of wort?
Wort attenuation limit (WAL) test
What does the term ‘attenuate’ mean in brewing?
To make thin or weak, describing the reduction in gravity or extract in the wort
What is the procedure for a WAL test?
Wort is added to a flask with yeast, kept warm and shaken until sugar consumption ceases
What is measured to determine the percentage of apparent attenuation?
The gravity before and after the WAL test
What does OG stand for in brewing calculations?
Original gravity of wort added to flask
What does PG represent in the context of WAL?
Attenuation limit test gravity
What is the formula for calculating apparent attenuation?
% Apparent Attenuation = ((OG - PG) / OG) × 100
What is the formula for calculating real attenuation?
% Real Attenuation = Apparent Attenuation × 0.819
What is indicated by a typical 75% fermentable wort in terms of apparent and real attenuation?
% Apparent Attenuation = 91.6%, % Real Attenuation = 75%
How can the fermentability of worts fermented in the brewery be calculated?
Using the OG and PG in the same way as WAL
Why is it important to regularly undertake WAL tests?
To highlight changes in the level of fermentability
What is the key to successful mashing?
Consistency
What are the positive effects of maintaining the correct particle size during wort separation?
Effective wort separation and minimised wort viscosity
What can excessive protein breakdown during wort boiling cause?
Excessive colour and flavour pick up
What is the impact of inadequate protein degradation on wort clarification?
Increases trub volume making clarification more difficult
What does a correct sugar spectrum provide during fermentation?
Consistent fermentations in the target timeframe
What can inadequate production of FAN lead to in fermentation?
Poor/slow/inconsistent fermentations
What does adequate breakdown of proteins, β-glucans, and pentosans allow during filtration?
Effective beer filtration
What ensures sufficient foam stabilising proteins in beer?
The correct level of protein breakdown
What can excessive lipid extraction lead to in terms of beer foam?
Reduction in foam stability
How does achieving a consistent sugar spectrum affect beer flavour?
Ensures consistent beer palate and aroma
