Brewing and beverage technology — removing residual yeast after storage and recarbonation In commercial beer clarification, once the product has been cold-stored (conditioning) and then recarbonated, which single operation is most commonly used to separate the remaining suspended yeast cells before packaging?

Introduction / Context:
Modern breweries must clarify beer to achieve brightness, stability, and a consistent flavor profile. After cold storage (also called lagering or maturation) and recarbonation, a small but significant population of yeast cells remains in suspension. Efficient removal protects flavor, appearance, and shelf life prior to final filtration or sterile packaging.

Given Data / Assumptions:

• The beer has completed storage/conditioning and has been recarbonated.
• Residual yeast is still present as fine haze-forming particles.
• Objective: separate yeast quickly at high throughput without degrading product quality.

Concept / Approach:

Separation methods rely on particle size, density, and process economics. Yeast cells are denser than beer and can be rapidly removed by centrifugal force. Industrial beer centrifuges (disc-stack designs) provide continuous clarification, minimal oxygen pickup, and gentle handling—making them the preferred pre-packaging step, often followed by polishing filtration.

Step-by-Step Solution:

Verification / Alternative check:

Breweries routinely report turbidity reduction from hundreds of EBC units to low values using centrifugation, with increased filter run length afterward—confirming centrifugation as the standard first-line clarification step.

Why Other Options Are Wrong:

Filtration (option b) can remove yeast, but using it alone for gross yeast removal reduces filter life and increases cost; it is typically a polishing step. Cell disruption (option c) would lyse yeast, releasing compounds that harm flavor stability. No separation (option d) risks haze, autolysis, and microbial instability. Flotation skimming (option e) is used in whirlpools for hot trub, not post-conditioning yeast removal.

Common Pitfalls:

Assuming filtration is always first—industrial practice often places centrifugation before filters to protect media. Also, avoid aeration; oxygen pickup can prematurely stale beer.

Final Answer:

Centrifugation