How important is it to punch down fruit?

[Drewch]

I just added fruit to my batch of lambic-inspired mixed-ferm (Bootleg's Sour Solera blend) ale --- how important is it to punch down the fruit?

I'm concerned that reopening the fermenter will just increase oxygen and exposure.

 

[BAF]

Is the fruit floating, or is it submerged? Personally, I've never really worried much about it. With clear fermenters, I've never really seen my fruit floating much. After making a mess once with raspberry seeds, I've used a paint strainer bag ever since, and I've never seen anything except maybe a little bit of the bag above the beer. Not sure if it's something different about frozen fruit (which is what I've used any time I've fruited a beer).

 

[Drewch]

This was thawed frozen fruit. It is floating - in retrospect, I could/should have bagged it with weights, but ... hindsight, 20/20, and all that.

Edit: I've only done fruit additions once before -- also with thawed frozen fruit, and I didn't do any punch downs (punching down ?) on that one.

 

[BAF]

I must have gotten lucky with mine then!

I'll defer to those with more experience than me. Mold won't grow without oxygen IIRC, but I don't know if other nasties will grow on exposed fruit (versus fruit soaking in alcohol).

Can you swirl/slosh the fermenter to encourage the fruit to sink?

 

[Drewch]

Can you swirl/slosh the fermenter to encourage the fruit to sink?

I could try. Maybe if took off just the airlock and gave it a vigorous swirl. They're only 3-gallon fermenters; I can manhandle them pretty easily.

It's already mixed culture and reasonably tart (I did a taste test when I added the fruit). So the only thing I'm really worried about is mold.

 

[Drewch]

Really, the airlocks are just filled with cheap vodka. I could just swirl 'em and then refill the airlocks if any spills.

 

[pvtpublic]

I hope this helps
My go to is high quality cans of fruit, typically what I canned myself. I prefer that over fresh fruit because the cellular structure has already been broken down (add a little pectic enzyme just to be sure) and more of the fruit can be released into the beer. And to be on point with the post, it's sterile! As long as your process is clean and sanitary, you don't have to punch it down. You don't have to use a bag, just rack off of it when it tastes just right.
Another good option is to make a fruit extract with vodka and what fruit you want. Pull your beer into measured out portions, add measured, but different, amounts of this tincture into each glass and taste. Adjust your volumes and dose it.

Edit: I'm sure your current batch will turn out just fine. Most of the organisms that can thrive in that environment now will only contribute a more complex character.

 

[mbronkalla]

When using cherries or berries, I swirl the fermenter every few days while it is still floating. Basically rocking the 5 gal in a big circle a few times, to keep it moist on all sides and prevent mold. As others have mentioned, a weighted bag makes less of a mess.