Haziness induced by bentonite?

[BarrelMonkey]

Last week I set up my first ever fining trial. I'm planning to make a sparkling blanc de noir this year, and my base wine is ready to rack into a keg for cold stabilization. I wanted to make sure that it is protein/heat stable, so set up fining trails with bentonite. I'm using Albumex, which is a calcium bentonite. You're supposed to be able to add directly to wine, though I resuspended it in (distilled) water first. Per manufacturer's directions I set up 3 doses: 1, 2 and 3 g/L (together with an untreated control, of course).

After a week, the bentonite seems to have settled. It's easy to see because my base wine still had a slight blush to it, which has dropped out. However, all the treated samples seem to have a haziness to them. It's a little hard to see in this picture but very obvious in real life:



Anyone encounter this? Right now I'm inclined to go without fining and hope for the best - the untreated base wine seems crystal clear.

 

[stickman]

You may want to take a look using a magnifying Loupe, just a SWAG, maybe the bentonite nucleated the potassium bitartrate precipitation.

 

[winemaker81]

Give it another week. IME most fining agents act fairly quickly, but I've had a few that took a week to really get working. I have yet to figure an explanation for those instances.

 

[BarrelMonkey]

Thanks @stickman and @winemaker81. Not sure about tartrates: I left my samples at room temperature (probably warmer than my cellar temperature) rather than in the fridge, so not sure that would be enough to promote tartrate precipitation?

In Daniel Pambianchi's Modern Home Winemaking book I think he suggests leaving wine on bentonite while it cold stabilizes so that you only have to rack off once; I've heard conflicting advice (Scott Labs, I think?) suggesting to leave no longer than a week. And I know one professional sparkling winemaker who never does any fining, and one who always does. As they say, 10 winemakers, 11 opinions...

 

[winemaker81]

In Daniel Pambianchi's Modern Home Winemaking book I think he suggests leaving wine on bentonite while it cold stabilizes so that you only have to rack off once;

This makes a lot of sense -- anything that eliminates a racking is good (well, within reason).

I'm going to the 2 week fermentation model (ferment to ~1.010, seal the fermenter, open on Day 14) as gross lees will have dropped, which cuts out 1 racking. I probably wouldn't do that for a light white, but for Chardonnay, yes.