Brewers make wort; yeast makes beer. In many of the breweries we audit, inconsistent flavour comes down to how yeast is handled. Here are the fundamentals every microbrewery should have in place.
Pitch the right amount
Under-pitching stresses yeast and can lead to sluggish fermentation, higher levels of diacetyl and other by-products, and unwanted fruity or solvent notes. Over-pitching can flatten the character of some styles. Lagers generally need considerably more yeast than ales. Use a consistent pitch rate for each recipe and record it.
Oxygenate the wort
Yeast needs oxygen at the start of fermentation to build healthy cells. Aerate or oxygenate cooled wort consistently, and avoid adding oxygen at any later stage.
Control fermentation temperature
Temperature is the most powerful lever on flavour. Ferment within the recommended range for each strain and make sure your glycol system can hold it, especially during hot weather.
Harvesting and repitching
- Harvest from healthy fermentations, ideally from the middle of the yeast cake in conical fermenters.
- Store harvested yeast cold and use it promptly.
- Track the generation number and replace yeast with a fresh culture after a set number of generations or at any sign of contamination or drift.
Check viability and vitality
A microscope, a haemocytometer and a simple staining method let you count cells and estimate viability. This turns pitching from guesswork into a repeatable process and is affordable for any brewpub.
Hygiene
Every vessel, hose and tool that touches yeast must be cleaned and sanitised. A single contaminated slurry can spread problems across several batches.
Keep records
Log strain, generation, pitch rate, temperatures and gravity readings for every batch. Good records make problems easy to trace.
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Our brewing operations and technical consultancy helps breweries set up yeast management, quality control and SOPs. We are based in Bangalore and support brewers across India.