We recommend harvesting yeast from beers that have a starting Plato of 18 °P or lower. At higher gravities yeast are put under significant stress that will decline overall yeast health.

Cool wort and aerate using standard brewery procedures.

Pitch yeast at a rate of 750K - 1.5M cells/mL/Degree Plato (depending on strain)

Monitor attenuation.

Dry hopping is detrimental to yeast health. We recommend harvesting yeast before dry hopping.

OPTION 1: PRESSURE METHOD

Cap the fermentor 1–2°P before terminal gravity.

Let pressure increase naturally as the yeast consume the remaining sugar.

Once the gravity has stabilized, increase the pressure to 8 psi by adding CO2 in through the racking arm (positioned upward).

Allow the yeast to settle into the cone for 12–24 hours.

OPTION 2: SOFT-CRASH METHOD

Once fermentation has subsided (3–5 days), set the fermentor temperature to 57–60°F.

When the target temperature has been reached, add CO2 through the racking arm to increase the pressure to 8 psi.

Immediately release the pressure with a quick burst by opening the valve connected to the blow-off. This will help break apart any top-cropping yeast.

Wait 24 hours for the yeast to settle to the bottom of the cone.

To prevent channeling, harvest yeast through a narrow diameter (0.75–1ʺ) sight glass and butterfly valve.

Verify yeast viability is above 90% before repitching.

Pitch yeast directly into another tank or store it in a brink for later use. Keep the yeast cold (32–40°F) if not pitched immediately.

If using a brink, a sterile filter can be used to allow off-gassing. Yeast will be healthiest if stored below 2 psi.

When ready to repitch the yeast, check viability and calculate the correct amount to match the specs of your next brew.

CELL COUNTING TIP: London-based strains tend to clump together, making counting difficult. To disperse cells for accurate counts, conduct dilutions in a 0.25 M EDTA solution.