Spunding and dry hopping

[sideguy]

Hi guys,
I brew a lot of dry hopped beers and would like to try to capture some natural co2 by spunding. My two concerns are dry hopping and yeast harvesting. Would anyone be willing to share any techniques they have used. I'm assuming add the hops, bung the fermenter just before reaching final gravity. Is there any way to harvest clean yeast? thanks for the input.

[HiFives]

This is a breakdown of what we came up with, but I'd love to see what others have done or hear feedback:

We close the blowoff valve at 1P from FG based on forced ferment test and raise temp to finish fermentation. We vent off from the CIP arm if the head pressure exceeds 15psi. After three days of unchanged gravity we chill to 60F. We use WLP007 which seems to floc hard even at that temp. We harvest after a couple days and I try to get in at least one more cone blow before dry-hopping. To dry hop we then bleed off the pressure from the CIP arm, put CO2 back on from the CIP arm so there's positive pressure in the tank, remove the PRV and add the hops. Once in we replace the PRV and repressurize the tank to a little under 15psi. On the second or third day we might hit the bottom of the tank with some CO2 for a few moments to mix things up again. We try to anticipate when to transfer based on experience and then taste. On transfer day, I lower the set point to 35 in the morning and move it to the serving tanks later on. Right now, we are not removing the remaining yeast and hops from the cone prior to transfer... just positioning the racking arm, though I wonder if it would help. Anyways, that's how we do it. Not exactly quick and easy. I'm curious to see what others have done and what you end up doing.

[coder]

To avoid bleeding off the pressure we use a small pressurized container for hops, that we connect to a ball valve on the top of the tank. You can see it in the film below, at 10:57

https://www.youtube.com/watch?v=C6wndwVQ9xY&t=664

[MikeS]

Wow- That's a really cool setup!

What kind of tanks are those? And who made the hop container? I've been looking into making some kind of hop cannon, but I do have a 4" port on many of our tanks so something like that might work really well.

Thanks for sharing and cheers- Mike

[coder]

All this equipment was made by Pacovskie Stroirny, Czech Republik.
But I guess, any welding shop can make such a container if you tell them what to do.