What is hop utilisation?

Hop utilisation is the percentage of alpha acids from hops that are isomerised (converted to iso-alpha acids) during the boil. These iso-alpha acids are what create bitterness in beer. Typical utilisation ranges from 5% (short boil) to 30% (60+ minute boil).

What affects hop utilisation?

The two main factors are boil time (longer = more utilisation) and wort gravity (higher gravity = less utilisation). Other factors include kettle geometry, boil vigour, hop form (pellet vs whole), wort pH, and whether the hops are in a bag.

Does utilisation increase indefinitely?

No, utilisation plateaus at around 30-35% after about 90 minutes of boiling. Beyond that, very little additional bitterness is extracted. Most of the useful isomerisation happens in the first 60 minutes.

Are pellet hops more efficient than whole hops?

Yes, pellet hops typically achieve about 10-15% better utilisation than whole/leaf hops. The pelletisation process ruptures lupulin glands and increases surface area, allowing more alpha acids to be isomerised during the boil.

How does wort clarity affect utilisation?

Clear wort generally gives better utilisation than cloudy wort. Proteins and other particles in cloudy wort can bind with iso-alpha acids and reduce effective bitterness. A good hot break helps improve both wort clarity and hop utilisation.

BrewCalcs

Hop Utilisation Calculator — Tinseth Method

Estimate hop utilisation percentage based on boil time and wort gravity.

Boil Time

Boil Gravity

How We Calculate This

Tinseth Utilisation

Utilisation = Bigness Factor x Boil Time Factor

Bigness Factor = 1.65 x 0.000125^(gravity - 1)

Boil Time Factor = (1 - e^(-0.04 x time)) / 4.15

The bigness factor decreases with higher gravity worts, reflecting the reduced extraction efficiency. The boil time factor increases with longer boils but approaches a maximum asymptotically.

Frequently Asked Questions

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Last updated: 2025-02-20

All calculations are estimates. Always verify values and adjust based on your equipment and ingredients.