How to adjust from a dry to port in the middle of fermentation

[mwhitnell]

Hi,
I am making a 5 gal batch of wine and may wish to adjust this recipe to port...Wondering if you can advise me the way to do this?
I have a primary going with 25lbs blueberries, 5 lbs of strawberries fermenting with EC-1118. Day 0 sg 1.102, with 8 lbs of sugar. Day 4 sg 1.015. I have been squeezing bag of fruit every day.

Option 1 I have thought about is to:
Ferment to .995 probably Day 7, ABV = (1.102-.995)*133= 14.1% Add 2.6 lbs sugar so the result is 18%ABV, Target sg for 4% added ABV , sg required is (4/131 + .995 = 1.025sg) so sugar neede is 261 * (1-1/1.025) = 6.36g/100ml, 5 gal equals 18,927ml so 6.36 * 189 = 1202g sugar or 1202g/454 = 2.6 lbs sugar; ferment til Day 10 or 11, so sg is ,995, Rack and add everclear 95% (1 liter) for 22% and back sweeten with corn sugar to Brix of 7.5 or so and add a liter of grape concentrate and 2 oz oak.

Option 2 Ferment to .995, Add (5.6 lbs) sugar (sugar needed for extra 4% = 1.025sg and for Brix 7.5 extra needed is 1.030 so need 1.055sg at this stage. Sugar needed is: 261* (1-1/1.055) = 13.6g/100ml or ((18927/100)*13.6/454) = 5.6lbs sugar and stop fermentation at sg 1.030, with a calculated ABV of 18%, no extra sugar needed. Add ever clear (1 liter) for 22% ABV, and grape concentrate and 2 oz oak in carboy.

Any thoughts or help would be great...maybe there is another way?
Mark

 

[JohnT]

Why not use the natural sugars already in your must? Is fermentation too far gone? If not, I would ..

Ferment down to a brix of 10 to 12% sugar remaining.

Using Pearson's square, figure the ratio of wine to fortifier to bring must up to 22 abv and add the appropriate amount of fortifier immediately.

 

[mwhitnell]

Added more sugar and still fermenting

Well,the sg got to .994 so I estimated that ABV was around 14%, so I removed the fruit bag and the volume was a little more than 4.25 gal, so I dissolved 5 lbs sugar in more water and added it to the 5 gal mark..fermentation is starting again. The yeast should go inactive at around 18% ABV, and I am guessing around sg 1.030 or 1.025 or so. At that point probably in a couple of days, I will keep checking the sg, and kill the yeast with 1 liter of 95% everclear.