There’s nothing like a wine with what I call “the elbows sticking out” to ruin one’s mood. Especially frustrating is when one has followed a recipe or kit instructions to the letter only to find that the procedure has yielded less than satisfying results. Spices and other added flavorings in home winemaking are one of the trickiest things to get right. Commercial winemakers also struggle with this issue as anyone disappointed over a lot of over-oaked Chardonnay can attest. “Flavor enhancers” (and I’ll include oak barrels in this as well as oak pieces) are so tough because once your wine has soaked in its new barrel (or with its little bag of cloves and cinnamon stick) for too long, these pesky aromatics are almost impossible to remove.
Unfortunately, this is the case for your banana wine. The strong clove aroma can only be toned down by blending back with more wine. There is no fining agent or simple filtration process that will materially change the aroma. Unlike protein or tannin molecules (which can both be fined out with bentonite and protein, respectively), aroma compounds are so teeny tiny that only very expensive (and industrial scale) nanofiltration technology can begin to remove specific aroma compounds. Some large commercial wineries have been successful at removing the aromas that contribute to cork taint and smoke taint. Though this technology continues to develop all the time, the industry will likely focus its efforts on aromas most of concern to wineries, especially TCA, Brettanomyces off-odors, pyrazines (green bell pepper aroma from unripe grapes), smoke taint and the like. Since table wine producers aren’t allowed to add spices like cloves or cinnamon or other flavorings like vanilla, (only the naturally-occurring aromas from grapes and from oak aging are allowed) I’m not anticipating any special clove-removal filtration being developed soon.
But back to the easiest thing you can do to try to ameliorate your wine back to a happy point of drinkability: back blending. Ideally, you would make an identical batch of banana wine, this time omitting the clove addition, and then dosing in the non-cloved wine with the spiced-up batch until you found an aroma balance that you liked. If this is not possible, don’t forget home winemakers always have the luxury of creative blending ideas such as blending with another batch entirely, trading some gallons with a friend to blend, or even (though I know some of you are opposed to this) buying some bottles of wine off the shelf (maybe an un-oaked Chardonnay would be appropriate here) and adding that material to your batch to cut down on the clove character.
As to how to prevent this kind of thing happening to you in the future, my biggest piece of global advice is to always take a “flavoring agent” recommendation in a wine or kit protocol with a grain of salt. Like salt is to food, what is written in the recipe might not be to your taste and you might want more or less of it. Additives like spices, extracts or essences often aren’t chemically or physiologically critical for the overall stability and soundness of a wine. A banana wine will still be a banana wine with 1 tsp. of cloves per batch or two. The latter will simply have more clove character and it might not be pleasant to you. The recipe elements that are critical, however, and which shouldn’t be messed with lightly include anything containing sugar, acid, water or yeast nutrients. Those form the foundation of the wine and will materially affect alcohol level and fermentation completeness. Things like tannin and fining agent additions start to enter a grey area but still should be followed close to the letter of the recipe. Additives like oak pieces, orange peel, ginger root and other spices are only there for aroma and flavor and in my mind can (and should) be employed according to individual taste.
But how can you know how much of an aromatic to add when you’ve never made the recipe before? Start small and work your way up. Cut the amount in half, add that and see how you like it. You can always add more. Or let your cheesecloth bag with the cinnamon stick and star anise only infuse in your carboy overnight and see how you like it before letting it steep for the week recommended in the recipe.
This type of step-wise adding is a very simple way of doing what I call “bench trials on the fly.” A proper bench trial is done “on the lab bench” and involves testing small, measured amounts of any additive (be it a blending wine, a fining agent or a spice) in a measured amount of wine, typically 50–100 mLs, letting the additive react and then smelling and tasting the results. It’s really the best way to treat a sample before inflicting a possibly unknown (and possibly damaging) process or additive to your whole batch. Additionally, I know many home winemakers just don’t have the micro-measuring equipment necessary (Eppendorf pipettes and accurate digital scales are very expensive!), so often this step-wise addition process is an easy-to-do compromise.