Hop Freshness

The Hop Freshness calculator estimates alpha acid degradation over time based on storage conditions.

How to Use

1. Select Hop Variety - Choose from database or enter custom

2. Enter Storage Details - Temperature, packaging date, package type

3. Input Original Alpha Acids - Listed on package

4. View Results - Current estimated AA%, percentage loss

About Hop Degradation

Hops lose their alpha acids over time through oxidation. The rate of degradation depends on:

• Storage temperature: Colder is better

• Packaging type: Vacuum sealed, nitrogen flushed

• Hop variety: Some varieties store better

• Time since harvest: Fresher hops last longer

• Exposure to oxygen: Minimized in proper packaging

Storage Guidelines

Temperature Effects

• Freezer (-20°C / 0°F): 5-10% loss per year

• Refrigerator (4°C / 40°F): 15-20% loss per year

• Cool Room (15°C / 60°F): 30-40% loss per year

• Room Temp (20°C / 70°F): 50%+ loss per year

Packaging Impact

• Vacuum + Nitrogen: Best preservation

• Vacuum Sealed: Good preservation

• Foil Pouches: Moderate preservation

• Open/Damaged: Rapid degradation

Hop Storage Index (HSI)

Different hop varieties have different storage stability:

• <30% HSI: Poor storage (Noble hops)

• 30-40% HSI: Moderate storage

• 40-50% HSI: Good storage

• >50% HSI: Excellent storage

Examples by Variety

• Cascade: ~48% HSI (good)

• Centennial: ~45% HSI (good)

• Saaz: ~25% HSI (poor)

• Fuggle: ~30% HSI (moderate)

Storage Tips

• Keep hops frozen for best preservation

• Vacuum seal opened packages

• Store in dark conditions

• Use oldest hops first (FIFO)

Calculating Adjustments

Example Calculation

• Original: 10% AA Cascade

• Storage: 6 months at 4°C (40°F)

• Estimated loss: 10%

• Current AA: 9%

• Adjustment: Use 11% more hops

Using with Your Brewing

• Calculate adjusted AA% for recipe planning

• Track your hop inventory freshness

• Adjust quantities to maintain target IBUs

• The tool remembers your last entered values