Fermenting 20 gallons, secondary or not?

[Grossy]

Is there any need to secondary 20 gallons batches?

I am in the planning stages to upgrade to 20 gallon batches. Currently I ferment 5 gallon batches in ale pales, for about 3 weeks.

I would love to hear from people who actually ferment 20 gallons at a time. My plan at this time is to ferment all 20 gallons, in a single vessel, with a flat bottom, not a conical.

 

[betarhoalphadelta]

Is secondary ever necessary??

Never done 20-gallon batches, but I've done 10 and 15. I do 10-gallon in a converted Sanke, and I used to do 15-gallon in plastic wine fermenters from Morebeer (i.e. food-grade garbage cans). With those sizes, secondary gets difficult, so I definitely don't do them. I even do my dry-hopping in the main fermenter.

What I do is make sure to crash-cool the beers in primary for a few days prior to packaging (I keg, and I can only imagine if you're doing 20-gallon batches, you will too). That assists clarity. I transfer to keg under CO2 pressure so I never have to move the fermenter to rack out under gravity, so that way I also don't disturb the sediment. Likewise I assume you're not going to be picking up a 20-gallon fermenter and lifting it up high to rack, so you're good there too. And for some batches I'll also hit it with gelatin in the primary while crash-cooling to really get it clear.

After all this, when it goes into the corny kegs it's nearly clear. I get little to no sediment in the bottom of the corny when I finish the keg and clean it.

Sorry I can't give you the exact answer, as I don't do 20-gallon ferments, but I think my experience is still relevant.

 

[Grossy]

bwarbiany;

All of your assumptions are right on. And I will definitely take the advice of a 15 gallon ferment over a 5 gallon ferment.

Basically, I dont want to make an assumption that scaling up from a 5 gallon fermentation to 20 gallons will be seamless. But your post is telling me that at this scale it is, at larger batches than 15-20 gallons that assumption may not be true (but I am not doing those).

I'll take real world experience any day, thank you.