Lack of sulfite can greatly reduce a wine's shelf life, as K-meta protects against oxidation and a plethora of micro-critters. You'll find that most people on this forum use K-meta.
A lot of fruit wines are astringent if unsweetened. That's among the reason why old recipes use a large amount of sugar -- the intention was the yeast would poison its own environment and stop eating before using up all the sugar. It worked, but there are thousands of strains of yeast, all with different ABV tolerance levels, so there was no guarantee how sweet the wine would be, nor if a given strain loved alcohol so you'd get jet fuel instead of wine.
Here's a hard fact -- you don't make wine. You will NEVER make wine.
Yeast makes wine. What you are doing is setting up the conditions so the yeast does its thing and that converges with your desires.
I say that tongue-in-cheek, but it is literally true. As far as a recipe goes? I don't exactly use a recipe, I use a
method.
1) decide how much fruit you will use per 1 US gallon / 4 liters of water. For plums, my guess 6 to 8 lbs. When ready, mix the fruit and water, and add K-meta to inhibit or stomp out competing microorganisms. Adding pectic enzyme will help break down the fruit, improving extraction, and will prevent possible pectin haze.
2) decide how strong you want the wine to be. I'd target 1.085 to 1.090 as the original SG (OG). The following day, stir your must really well and take a SG reading.
I wrote a post explaining how I determine how much sugar to use. [One reason for writing the posts is some topics get explained often enough that it's far easier to write it once and then point people at the post.]
Every time you add sugar stir well. Then stir again. And again. [Nope, not joking] Then check SG. If your final SG is off by a couple of points, it doesn't matter.
Add other ingredients, including acid. Plums are high in vitamin C, so it's likely citric acid will be a good addition, as will tartaric.
Add yeast nutrient. I use package directions, and add 2/3 that amount just prior to inoculation.
3) I make a
yeast starter the night before I'm going to inoculate. This gets the ferment off to a better and faster start.
4) Ferment in an open container covered with a towel, stirring 2-4 times per day, starting on the day after you inoculate. On day 3 or 4 I add the remaining 1/3 of the yeast nutrient when stirring. Ideally this should be added at 1/3 sugar depletion (e.g., if OG was 1.090, add around 1.060), but it's not exact.
5) I've been using a 14 day ferment in the last couple of years -- when then SG drops to 1.010, give the must a final stir and snap the lid on the fermenter and use an airlock. Leave until Day 14. The ferment will complete, and gross lees (fruit solids) should drop.
6) Day 14: press your fruit and move the wine into a carboy.
7) 1 to 3 weeks later, rack the wine and put it back into the carboy for bulk aging, at least 3 months.
This is a quickie off the top of my head. I'm sure I left things out, but it's a start.
Note - pay attention to units.
@Hazelemere works in Imperial gallons (which he explicitly states), most non-US folks work in metric, and Americans work mostly in US measurements. Make sure you're reading the correct units.
I try to work in metric because it's honestly easier and unambiguous. When working with small amounts of yeast and additives, it's far easier to work in grams and milliliters than anything in US measurements.
