An unexpected twist with my first batch of plum wine. It stopped fermenting after the primary fermentation, something that has never happened before in my experience. The primary fermentation is aerobic; the mashed up fruit, sugar and water sit in a large bucket covered loosely to keep out fruit flies. You stir the mixture occasionally, and as you do, you can see it bubbling vigorously.
After about a week the mixture is transferred to 1 gallon jugs with airlocks, so the fermentation can continue anaerobically. At this point the fermentation has typically slowed down considerably—because yeast growth is inhibited by the buildup of alcohol—but you’re still supposed to see bubbles come out of the airlocks.
I saw nothing, and thought the wine must have become contaminated somehow. I just let it sit for about a week, until I finally got around to buying a hydrometer; I had one before but lost it in the long period since the last time I made wine. A hydrometer measures the density or specific gravity of a fluid. When you begin the fermentation process, the SG is high, typically around 1.100, because of all the sugar dissolved in the mixture. As the sugar is converted by the yeast to alcohol, the density falls, and in a dry wine, with no sugar, it’s typically about 1.00. You can actually determine the alcohol content of the wine from the change in SG.
To my great surprise, that was the reading, very close to 1.00, indicating the wine had finished fermenting. It also did not taste sweet, consistent with the conversion of all the sugar. So I went ahead and bottled it, many months before I expected it to be ready.
Why did it finish so soon? I can only guess that the yeast I bought at the wine making shop was unusually resistant to alcohol, so that it was able to ferment all the sugar very quickly. But I’m still very surprised.
I got seven bottles plus a little more from this first batch, but could have made a lot more with all the plums available. This European variety is supposed to yield about two bushels of fruit. That is 64 quarts, about 64 lb, enough to make about 20 gal of wine, or 100 standard size 750 ml bottles!
That tree is done, but I have another one, a different variety, the fruit on which should be ready for picking in a few days. I expect to make another two gallons of wine, or ten bottles, from that. Enough!
After about a week the mixture is transferred to 1 gallon jugs with airlocks, so the fermentation can continue anaerobically. At this point the fermentation has typically slowed down considerably—because yeast growth is inhibited by the buildup of alcohol—but you’re still supposed to see bubbles come out of the airlocks.
I saw nothing, and thought the wine must have become contaminated somehow. I just let it sit for about a week, until I finally got around to buying a hydrometer; I had one before but lost it in the long period since the last time I made wine. A hydrometer measures the density or specific gravity of a fluid. When you begin the fermentation process, the SG is high, typically around 1.100, because of all the sugar dissolved in the mixture. As the sugar is converted by the yeast to alcohol, the density falls, and in a dry wine, with no sugar, it’s typically about 1.00. You can actually determine the alcohol content of the wine from the change in SG.
To my great surprise, that was the reading, very close to 1.00, indicating the wine had finished fermenting. It also did not taste sweet, consistent with the conversion of all the sugar. So I went ahead and bottled it, many months before I expected it to be ready.
Why did it finish so soon? I can only guess that the yeast I bought at the wine making shop was unusually resistant to alcohol, so that it was able to ferment all the sugar very quickly. But I’m still very surprised.
I got seven bottles plus a little more from this first batch, but could have made a lot more with all the plums available. This European variety is supposed to yield about two bushels of fruit. That is 64 quarts, about 64 lb, enough to make about 20 gal of wine, or 100 standard size 750 ml bottles!
That tree is done, but I have another one, a different variety, the fruit on which should be ready for picking in a few days. I expect to make another two gallons of wine, or ten bottles, from that. Enough!