A 325 mL bottle requires slightly more than one lb of blackberries. Therefore, to fill a 21 L carboy, you will require at least 70 lb of blackberries. Pick only the black ripe berries; none with any red parts. To remove most of the juice from the berries, the cell membranes need to be broken which is why you must freeze the berries. Do NOT ferment the berries with seeds! If you do, the final product will be bitter. In fact, no country wine should be fermented on the seeds or stones for the same reason. Loganberries make a superior product so, incorporating maybe 10% will improve the flavour of the finished port. John’s method is to place picked berries into in 22L plastic pails with lids and then freeze them. If you are making large quantities of port you may need access to a cold storage company to freeze the pails. For lesser quantities a chest freezer will hold 4-5 pails, depending on it’s size.
Preparing the must
Once the appropriate volume of frozen berries has been accumulated, they should be removed from the freezer and allowed to thaw. This usually takes 2-3 days. Often there will be an accumulation of white mould on top of the berries; this is of no concern. Press the now semi-liquid berries and be surprised how much juice is released. Also extent the press time for a few hours, for, unlike grapes, juice keeps being produced. John had a couple of large presses and, by pressing all night, got an extra 40 L of juice! At the conclusion of pressing there will only be dry seeds. Add pectic enzyme, SO2 50 ppm and leave overnight.
Test the must for Brix, pH and TA. You will find that the Brix= 12, pH =3.37- 3.40 and TA about 12. No need for any adjustment as the final product will be sweetened. Add enough sugar to bring the brix up to about 21 and inoculate with an alcohol tolerant yeast such as EC1118. Refer to Scott Labs http://www.scottlabsltd.com/resources/handbooks/ for methods related to yeast rehydration with Goferm, and additions of yeast nutrients such as Fermaid K. Keep adding small amounts of sugar to keep the fermentation going to completion. This method should result in an alcohol content of 13.5 -14.0 v/v when fermentation stops.
To bring the percentage up to 17.5 – 18, always use an expensive cognac as a source of alcohol for best results. Look up Pearson Square on the internet for details, but it works like this:
Subtract % alcohol in wine at time of fortification from the desired %. This will be the volume of spirit to add.
Subtract the desired % of alcohol in the finished port from the % of alcohol in the spirit used for fortification. This will be the volume of wine to add.
No further SO2 will be required because of the high alcohol content. Let the wine settle for approximately 6 months, rack and proceed to sweeten.
Make up a sugar solution by weighing 75 g (or 75cc) sugar and bringing up the volume with added boiling water to 100cc. Add 100 cc of finished wine to a few wine glasses. Add 2- 5 cc of the sugar solution to the first glass and taste. Vary the sugar additions until there is agreement amongst your testers that the correct or desired sweetness has been achieved. Since each cc of sugar solution added contains .75 gm sugar, each liter of wine will require 7.5 gm sugar for each cc added to the 100 cc test.
Contributed by John Wrinch. John bottles in 325 ml dark bottles for a great looking presentation of a wonderful wine.