The Importance of Wort Cooling and Oxygenation Flashcards
(15 cards)
What is the cold break in wort?
The interaction of protein compounds with polyphenol compounds upon cooling, forming precipitates.
What percentage of total protein content is typically precipitated as hot and cold break?
15-35%
At what temperature range does significant cold break formation occur?
Below 20-30°C
How does cold break affect the visual shelf life of beer?
It decreases the visual shelf life.
What is the size of cold break particles compared to hot break?
Cold break particles are generally around 0.5 mm and much finer.
What can increase the amount of cold break and the size of flocs?
Using processing aids.
What are chill hazes?
Particulate matter that re-dissolves into solution at higher temperatures.
Why is cold break important in brewing?
It is critical for achieving a clear beer with good colloidal stability and shelf life.
What are some flavor and process problems caused by excess trub?
- Formation of ‘dirty yeast heads’ in top fermenting yeasts
- Trub coated yeast affecting fermentation performance
- Removal of metal ions like zinc
- Excess lipids causing flavor stability and foam problems
- Sulphur flavors like ‘vegetable’, ‘stewed’, or ‘cabbage-like’
- Difficulties in filtering and clarifying beer
What is a method to limit trub carry-over?
Well managed boils and wort clarification processes.
What flotation techniques can be used to remove trub?
Floating off the trub using air or inert gases.
When should skimming be done for top fermenting yeasts?
After 12-24 hours.
When should cropping be done for bottom fermenting yeasts?
After 6-12 hours.
What is the typical amount of cold break some breweries prefer to remain in the fermenter?
50 mg/L
What is the potential wort loss when removing 60% of the cold break?
0.2-0.4%
