We recently introduced a Limoncello to our line up that has been very well received. We are on our third batch, the first batch had no issues, batch two and three had the issue. This being that once bottled, we are seeing lemon oils (we assume) breaking out of solution and forming a layer on top of the limoncello once bottled. There is no layer floating in the bulk tank we are bottling out of, so we are led to believe something is occurring during bottling.
It is a simple set up, bulk tank with screen gasket to catch any larger chunks of zest. We were then going thru a cartridge filter setup that all our spirits get. We thought maybe this was the culprit, but after removing it, the same issue persists. Bottle filler is an Enolmatic.
The layer forms within 30 minutes max of botting, and if bottle is vigorously shaken, it reappears in the same timeframe. Any thoughts other than a "floating oil in natural" sticker?
Photos? Can you describe your process a little bit? What's the ABV of the finished product? What size filter do you use?
Try filtering it into another tank, giving it time to separate, and then fill off the bottom of the tank paying close attention to the oil line.
It's possible that the physical agitation during bottling is sufficient to cause your saturated oils to precipitate out of solution if you are on the bleeding edge. But that doesn't solve the issues, too much oil, too little solubility. Sometimes higher proof, like @foreshot is eluding to, can help keep oils dissolved. Or, reduce the overall amount of citrus peel relative to the liquid volume.
You might have some luck switching to cellulose filter pads along with a plate and frame, with hopes that some of that oil stay absorbed in the filter media, but keep in mind most of what we call "citrus oil" is far too small to be physically captured in a filter cartridge.
Lemon zest is soaked in our 190 proof for a couple weeks. Proofed down to 60 proof with sugar and water. The filter is .2 micron which I realize is super small, just what I had.
Silk - we have been bottling out of a conical tank with this in mind, but the strange thing is no oils in bulk. I will try filtering from proofing tank to the conical bottom bottling tank, rest, then bottle to see if that works. If not I will also visit reducing the amount of zest I use.
Last ditch effort will be a label or sticker marketing the oils, which I almost want to do anyway as I feel this is a sign of good extraction and a high quality limoncello. But want to get ahead of any complaints and concerns from consumers before we get them.
Thanks for the suggestions