Describing what beer clarity is, how its defined and measured and the potential causes of haze or clarity problems in beer.
When Clarity Matters
Even a high quality haze meter has its limitations due to a phenomena called “pseudo-haze”. Pseudo haze is when you have haze that is detectable by a haze meter, but may not be visible to an observer. Pseudo-haze is caused by small particles that reflect light but don’t affect the clarity of the finished beer.
The term “turbidity” is used to describe the particles that are visible, and pseudo-haze is the difference between the haze measured by the meter and the “turbidity” actually visible in the finished beer. Pseudo-haze can be a real problem for commercial brewers who want to consistently measure and control the haze stability of their beer.
Types of Haze in Beer
Potential Causes of Haze in Beer
The other causes of haze which are less common include:
- Calcium deficient worts (causes Oxalates)
- Wheat derived adjuncts (causes Pentosans)
- Inadequately modified malt (Beta-glucans) – though very uncommon with modern malts
- Dead bacteria from an infection
- Damaged or overstressed yeast (Induces carbs and proteins)
- Lubricants, excessive finings or other foreign material in the beer
That’s a quick overview of measuring haze and the major causes of clarity issues.