Fining

I have never used isinglass for fining, and my impression is that its use among home winemakers isn't as popular as other fining ingredients like Sparkolloid, betonite, gelatin, Kieselsol and Polyclar.

The problem I've had with Sparkolloid is that unless you will filter your wine after treating, you will need to allow plenty of time (4 to 6 months) after fining for all the fine particles to settle out of suspension to avoid ending up with floaters later in the bottle (even when the wine looks perfectly clear when bottled). You can try fining first with Sparkolloid and then follow it up with a betonite "topping", but the betonite itself will leave large fluffy lees that can be difficult to rack off of. This works though, I believe, because betonite is negatively charged while Sparkolloid is positively charged, so the betonite will attract the remaining Sparkalloid particles. Sparkolloid usually leaves wine very clear very quickly. Sparkolloid should be added to the wine hot, and betonite needs to be blended into a slurry with water.

Some of the easiest and cleanest finings are the two-packet varieties like "KC Kler", usually containing a packet of Kieselsol and I think another of gelatin. This leaves nice, compact lees in short time that are easy to rack off of. Down side is that it's a bit more expensive and the shelf life of the packets doesn't allow you to keep a supply around like you can with betonite or sparkolloid.

Popular finings for red wines are betonite (which you can even use during the primary fermentation if you like), egg whiles (for a very light "polishing" fining), and gelatin (if you want to soften a tannic wine since gelatin removes an equal quantity of tannin). Egg whites won't have much negative effect on the wine, but both betonite and gelatin can remove some color and taste, so best to use them conservatively.

Polyclar is an unusual fining ... you normally don't want to use it on a red wine, because it will remove some color. But, if you have a wine that has oxidized a bit (say an apple wine where the fruit was damaged, or a raisin wine or from other dried fruits), Polyclar can sometimes work wonders, clearing up the browning and removing tannin and bitterness.

Sorry, I don't have any experience with Isinglass, but I'm sure someone else can fill in info on that one. Keep in mind that all finings need to be mixed well into the wine. You can buy a wine stirer that will attach to the end of a power drill to make the easier (it's a rod that has two fins at the end that fold up to enter through the mouth of the carboy, and then deploy out into the wine for stirring).

Jon [Check out my winemaking homepage