[This is the conclusion of a two part blog post. See the previous entry for the beginning of this post.]
The Alcohol Level Needs To Kept In Balance.
In general, the fuller the flavor of a wine, the higher the alcohol level must be to keep it in balance. Wines that do not have enough alcohol as compared to their flavor intensity, will taste harsher. The astringent characters of the wine will be highlighted in the wine's final flavor profile.
To help put this into better perspective, lighter white wines tend to be around 10% alcohol, while the heaviest of reds tend to be around 14%. The particular blueberry wine recipe you are considering is shooting for around 11.5% to 12%, that is, if you follow the homemade wine instructions.
This alcohol level is based on both the amount of sugar and fruit called for in the recipe. Both of these ingredients are wine making materials that provide fuel for the wine yeast to turn into alcohol.
If you decide to add additional blueberry, then you should probably shoot for more alcohol. Not necessarily 14%, but maybe somewhere around 12.5% or 13%. There is no exact amount that is correct. This is where some art, finesse and experience comes into play.
To control the finished alcohol level of a wine, you need to control the beginning sugar level. This is done with the "potential alcohol" scale on the gravity hydrometer. Once the crushed berries and water are mixed together, instead of adding 11 pounds of sugar as directed by the recipe, just keep dissolving sugar into the wine must until the potential alcohol scale on the gravity hydrometer reads 13%.
More Flavor Means More Aging.
Another consideration that must be thought through before increasing the amount of fruit is the amount of aging that will be required before the wine is considered ready for consumption.
Here again, the more fruit you add, the more aging the wine will need before it comes into its own. With the original 13 pounds of blueberries, maximum aging would be around 6 to 9 months. With 20 pounds it may take as long as 12 to 18 months before the improvement brought by aging is fully realized.
This does not mean that you can not drink the wine before this. It just means that you can expect the wine to continue improving with even more time. Again, neither I nor wine making books can tell you when the wine has reached full maturation, this is for you to learn how to determine on your own as you sample the wine through out the aging process.
As You May Begin To See...
There are a lot of factors that go into putting together a solid wine recipe: picking out the various wine making products; determining their amounts, etc.
All the recipes we offer on our website have been bench tested and used many, many times. While you are free to alter them as you like, realize that any changes you make to any one ingredient, usually means that you will need to change another ingredient to keep things in line.
Happy Wine Making