Adding fruit to keg...blow off assembly needed? Or pulling PRV occasionally ok?

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Unicorn_Platypus

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Never brewed a beer with fruit, but now that I'm kegging I figure it would be fun to throw some into a keg an referment.

Do I need to rig a blow off tube from the gas line out or am I good just leaving the keg sealed up (and occasionally pulling the PRV?

I'm OCD about avoiding O2 pickup and would prefer to add to a fully purged/sealed keg (keeping positive pressure) and wait until fermentation restarts to release any CO2.

I've got a Clear Beer Draught System with 300 micron screen so not worried about clogage.
 
I prefer using kegs as secondaries. They are air tight and can be purged well.

You can use a spunding valve to control pressure. Bobby sells a "re-engineered" one (using a looser spring) that has a range that's actually useful for us brewers.

When adding fruit (hops, spice, syrups, or anything else) flow CO2 in through the gas post at around 12 psi while removing the lid (keep PRV open). Then purge headspace afterward for all security.

Much fruit tends to float, keep that in mind with your Clear Beer system. Some periodic agitation may be needed to keep additions submerged or suspended and maximize extraction. Shaking, rolling, rocking, swirling, whatever it needs.
At the end you can jump the infused beer into a "serving" keg. As usual, 100% liquid pre-purges are your ally against oxidation.
 
I prefer using kegs as secondaries. They are air tight and can be purged well.

You can use a spunding valve to control pressure. Bobby sells a "re-engineered" one (using a looser spring) that has a range that's actually useful for us brewers.

When adding fruit (hops, spice, syrups, or anything else) flow CO2 in through the gas post at around 12 psi while removing the lid (keep PRV open). Then purge headspace afterward for all security.

Much fruit tends to float, keep that in mind with your Clear Beer system. Some periodic agitation may be needed to keep additions submerged or suspended and maximize extraction. Shaking, rolling, rocking, swirling, whatever it needs.
At the end you can jump the infused beer into a "serving" keg. As usual, 100% liquid pre-purges are your ally against oxidation.

Great suggestions! Thanks!

Two follow up questions:

Do I need to worry about liquid spraying out the spunding valve during active refermentation?

Who's bobby?
 
Great suggestions! Thanks!

Two follow up questions:

Do I need to worry about liquid spraying out the spunding valve during active refermentation?

Who's bobby?
Most secondary fermentations aren't and shouldn't be very vigorous, causing blow off. Aim at leaving at least a quart of headspace in the keg after adding fruit. That's the only drawback on using (corny) kegs as fermenters, your final volume will be less than a keg.
You could ferment 3 quarts to a gallon of beer in a smaller container (gallon wine jug) and add to the serving keg to top it off. All under CO2 if possible.

Some cut the gas dip tube down to 1/4-3/8" to further reduce the chance of liquid/foam coming out.
The internal pressure also curbs excessive foaming.

Bobby is a sponsor here who owns BrewHardware.com:
https://www.brewhardware.com/product_p/spundingvalvetee.htm

Or the one that also has a gas input:
https://www.brewhardware.com/product_p/spundingvalvecross.htm
 
Most secondary fermentations aren't and shouldn't be very vigorous, causing blow off. Aim at leaving at least a quart of headspace in the keg after adding fruit. That's the only drawback on using (corny) kegs as fermenters, your final volume will be less than a keg.
You could ferment 3 quarts to a gallon of beer in a smaller container (gallon wine jug) and add to the serving keg to top it off. All under CO2 if possible.

Some cut the gas dip tube down to 1/4-3/8" to further reduce the chance of liquid/foam coming out.
The internal pressure also curbs excessive foaming.

Bobby is a sponsor here who owns BrewHardware.com:
https://www.brewhardware.com/product_p/spundingvalvetee.htm

Or the one that also has a gas input:
https://www.brewhardware.com/product_p/spundingvalvecross.htm

Awesome! Thanks
 
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