Maple sap is a great source of natural sugar and certainly qualifies as home winemaking material. What is less certain, as you’ve found out, is how much of those subtle maple aromas and flavors will stick around in a finished wine. I’m glad you’re experimenting with adding acid. Like you’ve discovered, maple syrup just doesn’t have enough natural acid on its own to create a balanced finished product. Acid blends will usually have a combination of malic and tartaric acids, which better mimic a grape’s natural acid profile and will help contribute to a better eventual mouthfeel and refreshing “zing.”
Lemon rinds, especially, as you’ve discovered, can contribute what is perhaps unwanted lemony aromas and flavors. Don’t forget that what makes a lemon “lemony” is all about that tiny, thin layer of yellow-colored zest on the very outside of the fruit. It’s after all why a martini “with a twist” can taste so citrusy with just a brush of lemon peel. The pith, or the white part underneath the yellow peel, is chock full of bitter and astringent compounds that you most likely don’t want to get into your finished wine. It’s undoubtedly contributing to those “lemonade” flavors that you describe not wanting.
To improve body and overall mouthfeel profile I suggest replacing about 1⁄4 to 1⁄3 of your sugar source (maple syrup) with a neutral white grape juice concentrate like Thompson Seedless or even Chardonnay. This will provide enhanced natural acid and body components and will also provide better yeast nutrition.
You might be interested in experimenting with some of the revolutionary liquid oak tannins that have hit the market in the last five years or so. Companies like AEB, Laffort, and Enartis (all can be found online) sell products that can enhance and amplify some of the lovely vanilla, caramel, and even maple flavors that oak aging brings to wine. Contact them to get some advice from a sales rep. I also think you might benefit from aging your maple wine on some kind of toasted oak product, again, to enhance and reinforce the maple, toasty, and baking spice notes that you are looking for.
If you’re looking to get more additional natural maple flavor into this project, might I suggest shopping for a little bottle of natural maple flavor online or at your local natural foods store? Because home winemakers aren’t bound by the same rules that commercial wineries are, you can add whatever finishing aromatic compound you’d like — flowers, fruit peel, vanilla, or maple extracts . . . let your palate and imagination be your guide. Add it when your wine is done fermenting (make sure it doesn’t contain any sugar — most do not) and in very small initial doses as some brands are quite strong.
Thinking even further outside the box, candy cap mushrooms provide a distinct maple flavor and aroma. You could make a tincture with them and add that to your fermented wine, or even loosely bag the dried mushrooms and let them age in the wine for a while.
Maple wine sounds like a great brunch wine with pancakes! My parents have close friends who have a maple stand in Canada and we’ve enjoyed their products on our pancakes for years. We admire the time, dedication, craft, and tradition it takes to produce maple products. I applaud you from afar in your efforts to create a maple sap wine!
