Here's how to make a gallon of wine with fresh grapes:
1). Crush the grapes with your hands or with a press thoroughly. 10 pounds of grapes is enough to make about a gallon of wine.
2). Add about 1/3 gallon of hot water to your grape crush, and mix well.
3). Add your sugar according to the drink designer.
Different grape varieties have much different sweetness levels, so here's how you can determine how sweet your juice is:
If your juice tastes as sweet as Welch's store-bought grape juice, you can put in 35g of sugar per 8 fl oz into the sugar calculator.
If it tastes significantly sweeter than Welch's, you can put in 50g of sugar per 8 fl oz into the sugar calculator.
And if it tastes tarter than Welch's, put in 25g of sugar per 8 fl oz.
4). Strain out most of the grape crush from your juice. The more you leave in, the darker, dryer, and more acidic your wine will taste.
5). Pour your mixture into your fermentation container.
6). Add your brewsy bag and shake vigorously!
7). Ferment your wine for approximately 5 days. Before you move it to the fridge, taste-test for sweetness. If it tastes too sweet, let it ferment for 2 more days. If it tastes dry enough for you, move it to the fridge.
Remember that you're taste-testing for sweetness here, not flavor. The flavor will massively improve in the next steps.
8). Put in the fridge for 2 days, then rack your wine into a new container. Try a glass, then move back to the fridge.
9). If you've decided to make your wine quite dry, you'll want to plan to let your Brewsy age for 2 to 3 weeks for it to mellow out a bit and for those complex, nuanced flavors to really come out (sweet wine will mellow out faster).
Let it age in the fridge with the lid on loosely, and rack it when you see a large amount of sediment start to build up at the bottom.