After two seasons in which the orchard didn't produce a crop, 2018 saw a bumper crop of peaches for Antietam Creek Vineyards. We decided to try our hands at making peach wine, a first for both of us. Although I already had an inclination to process this like white grapes, I was curious to see the literature on commercial peach wine production. Apparently, there is none (that I found at least). What I did find was for home peach winemaking which has you ferment macerated, halved and pitted peaches in bin, a process I generally avoid with grapes if I can help it.
We picked tree ripened peaches and attempted to crush them with a grape crusher before sending the pulp to the press. This didn't work, so halved, pitted peaches were sent directly to the press. Even though tree ripened peaches are soft for eating, they're still too hard to press in a grape press. We let the pitted peaches soften overnight under a cover of carbon dioxide in a grape harvesting bin. This did the trick so we loaded halved, pitted peaches directly to press on day 2. I added rice hulls as a pressing aid. Unlike whole cluster grapes going to press, peaches have nothing to press against to release juice. While grapes have tough skins and stems, peaches are just a big sloppy mess that presses rather poorly. Rice hulls are used as a pressing aid for difficult to press grape varieties, and they worked in this situation too. We yielded 168 gallons per ton, a number similar for whole cluster pressed grapes. However, the peaches pressed poorly, I couldn't press beyond 0.4 bar, very low by grape standards, and the peach pulp was fairly wet after pressing. Nevertheless, we were happy to have achieved the yield that we got.
When processing white grapes, you ferment only the clarified portion of the juice. To that end you send the juice from the press to the settling tank and rack (decant) clarified juice after settling overnight. Most grape varieties settle without intervention rather well. Peaches do not, so I added pectinase and hemicellulase enzymes to help the process. This worked, though I didn't get as thorough and clearly defined separation between juice and sediment that I find with grape juice. The clarified juice was sent to the fermentation tank where I added wine yeast, yeast nutrient, and a lot of sugar. These peaches came in at 10° Brix (% sugar) and would only have yielded about 6% alcohol. We're shooting for about 11% alcohol, so the fermentation was chaptalized with cane sugar to about 18° Brix. The pH of the juice was 3.75, and tasted plenty acidic, so no acid addition was made.
The fermentation is now complete and we're waiting for the wine to clarify by gravity before we send it to stainless steel drums to further clarify before bottling early next year. Any wine is difficult to assess for quality at this stage. But so far the wine appears clean and have mild peach character. And this is roughly what we want, an elegant and clean wine. Many fruit wines are grape wines with fruit concentrate added. We're aiming for an upscale wine that is 100% estate fruit wine.