Blackberries, sanity check

[Sausages]

I have a 40 pint porter kit in the FV at the moment, just finishing primary fermentation. The plan this weekend is to rack to a second FV and add some blackberries.
I have about 2kg of berries which were picked from the garden, washed and frozen last year. From reading around that should be about the right quantity.
My initial plan was to defrost the berries in a sanitised FV, rack onto them, let the secondary fermentation do its thing then get it in the keg.
Then I started thinking! (dangerous)
Am I going to be left with a pile of fruit pulp in the FV at the end of secondary that I can't squeeze the liquid out of? I could possibly put the fruit in a sanitised pillow case or similar, which I could remove and squeeze in a sanitary fashion before the beer comes out of the secondary FV and into the keg.
or!
I could defrost and mash the berries up first, passing them through a sieve before they go in the FV, so I'm only adding liquid to the FV. That also gives me the option of heating the liquid up to sanitise it (I assumed freezing would do that, but am sort of on board with the thinking you need heat rather than cold)
Anybody got any advice on any of these approaches?

 

[Clarence]

Last year, I chucked about 3 kg of raspberries in a brew. Let them defrost overnight and in they went. Don't recall any issues with pulp or volume loss. I'd just throw them in before they start to ferment under their own yeasts.

 

[NotSure]

I make a few fruit beers a year and learned the hard way about getting pulp stuck in valves years ago. What I've been doing successfully to avoid problems since is:
(1) freeze the fruit, then thaw (repeatedly if you have time and patience)
(2) put the fruit in a nylon bag in the second FV
(3) mash the fruit with a potato masher and tie the bag off
(4) rack onto the fruit

Good luck!

 

[Sausages]

Thanks for the advice. I like the point about freezing/thawing a few times, that should help break the fruit up I guess?
To update this, once defrosted I mashed the berries up as they were mostly still intact and I wasn't sure they would all fully break down in the brew. I heated them up to 80C as well as I wasn't sure about the sanitary qualities of my potato masher! I chucked them in a second FV once cool and racked the wort on top of them. by the next day bubbling had picked up again so something is going on in there. I was going to wrap the berries up in a muslin cloth after mashing but the ones I had weren't big enough. I'll wrap one around the syphon inlet to stop it blocking up when the time comes.

What I didn't do was take a gravity reading before or after adding the berries so not sure how I gauge the final ABV.

 

[Clint]

Make a pie.

 

[Stevieboy]

I would thaw and blitz with a blender.

 

[NotSure]

Thanks for the advice. I like the point about freezing/thawing a few times, that should help break the fruit up I guess?
To update this, once defrosted I mashed the berries up as they were mostly still intact and I wasn't sure they would all fully break down in the brew. I heated them up to 80C as well as I wasn't sure about the sanitary qualities of my potato masher! I chucked them in a second FV once cool and racked the wort on top of them. by the next day bubbling had picked up again so something is going on in there. I was going to wrap the berries up in a muslin cloth after mashing but the ones I had weren't big enough. I'll wrap one around the syphon inlet to stop it blocking up when the time comes.

What I didn't do was take a gravity reading before or after adding the berries so not sure how I gauge the final ABV.

Yes, the freezing/thawing makes them mushy so it helps break them-up.
For blackberry Puree 6 PPG or 48 PKL according to John Palmers book. Taking the gravity before adding berries isn't going to matter to get the new ABV because the sugar's locked-up in the berries. So, add the sugar contributed by the Blackberries to the OG and compute ABV from that and the FG.

 

[Jim Brewster]

You do inevitably lose a bit of beer to the berries but it's not as much as say dry hopping. I did a Stout with blackberries added after initial fermentation (250g/L I think, added while still frozen), it turned out quite nice but a little more tart than I expected due to the sucrose, so it's worth thinking about balancing the sucrose with some grains with body from the outset.

I think for Stout or Porter, extracts actually give a better result as they don't thin the mouthfeel, although I did a Munich Wheat beer with what I had left over, and that was very good.

 

[periolus]

With frozen fruit, could you make a ‘lumpy’ (not too mashed) compote with half a Campden tablet thrown in to sanitise and kill any wild yeast. Sounds like it should work, but never tried it.