The basic Blackberry Port recipe is:
1 Gallon of Blackberries (about eight pounds)
1 pint (pound) of sloes
1 pint damson plums
1 gallon boiling water
1/2 oz yeast
1 large slice of bread - toasted
In a clean (plastic) bucket pour the boiling water over the fruit. leave for eight days, tightly covered with a muslin cloth. M ash the mixture each day with your fingers or a wooden spoon
Strain and squeeze every drop of moisture from the fruit before throwing it away. This is best done first through a fine sieve and then putting the remaining damp pulp in a old clean cloth such as an old tea towel and using that like an icing bag but with no nozzle or holes.
Strain the liquid collected so far through three thicknesses of muslin
Add the sugar and stir until it is dissolved. Spread the yeast over the toast, and float it on the liquid yeast side down. cover the bucket tightly with a clean cloth and leave in a warm area for a week to ferment.
Then skim and put into loosely corked bottles, or bottles corked with cotton wool and put in an area with a steady temperature. NOT THE ATTIC OR AN OUTBUILDING - for at least seven months.
Drinkable after this time, but best kept in firmly corked bottles for at least a year. Reaches its' best in 3-5 years, still good after this. Ten years longest kept
As you can tell from the above this is a very old Craft recipe from 100+ years ago. What I do is use a plastic bucket, rinse all the equipment with boiling water to sterilise it and make sure I tie a cord tight around the bucket to keep the vinegar fly out.
I also put the fermenting liquor into gallon jugs, having first sterilised them buy filling them with water and adding two baby bottle sterilising tablets. Then rinsing them out and adding the
liquor as described. Then I cork them tightly with cork pierced for an airlock, add that, and leave it to 'work', usually in a quiet corner of the kitchen. When fermentation stops I pour the new wine into bottles, cork them tightly, and leave them to mature. Usually for 18 months plus
Remember, the measures are all imperial and will need to be converted to their US equivalents.