Port wine is a type of fortified wine that is made exclusively in Portugal adhering to a unique technology. We’ll go over the adapted classic port wine recipe so that you could make your own best port wine at home. The port recipe is fairly simple, but you’ll have to make some calculations.
To make homemade port with a premeasured ABV and sugar content, you’ll have to obtain certain winemaking equipment: alcoholometer and saccharimeter. If you don’t have these, you’ll have to take measurements by eye, using approximate values.
Most types of port are made from red grapes but white grapes are okay, too. The amount of sugar depends on the initial sugar content of the grapes (the higher the content, the better) and the desired sweetness of the final product. If the grape juice is too sour, you should dilute it with water. Keep in mind that sugar and alcohol lower acidity themselves, and water substantially decreases the quality of the drink.
In the traditional port winemaking technology, 144 proof grape is added to the fermented must. After that, the cut is put into casks. Of course, few people can afford aging wine in casks or infusing it with oak chips. However, you can imitate aging by swapping grape distillate with at least 3-year-old brandy of high quality.
The best way to ferment the must is by adding wild yeast contained on the surface of grapes. You can play safe by adding wine yeast—sherry strain works best!
- Grapes – 10 kilos
- Sugar – up to 250 grams per 1 liter of juice
- Water – up to 30 ml per 1 liter of juice (in rare cases)
- Grape alcohol or brandy – 1.2-6.5 liters
- Wine yeast – per 10 liters of must (optional)
How to Make Port Wine at Home
Sort out the grapes and make sure to remove the stems and leaves as well as any unripe, moldy or spoilt fruits. It’s better to pick unwashed grapes in dry weather so that to preserve wild yeast on their surface, as it will start fermentation. Sterilize all used containers and tools with boiling water, then wipe them dry with a clean cloth to avoid contamination with mold and other pathogens.
Crush the grapes without damaging the seeds—otherwise, must will turn out bitter.
Put the obtained grape mash into an enamel or plastic container with a wide neck—a cooking pot or a bucket will do. Leave about a quarter of the volume free for foam. At this point, you can optionally add wine yeast. If the grapes are very sour, add 100 grams of sugar and 30-50 ml of water per 1 kilo of grapes. Stir into must.
Cover the container with cheesecloth and leave it in a dark place at 18-27 °C. Stir once every 8-12 hours. Without this the must might go sour. After 12-24 hours surface should foam and bubble—this means that fermentation has started.
After 3 days, strain the juice through a few layers of cheesecloth and squeeze the pulp dry (it’s no longer needed).
Determine the sugar content of the strained juice. It should be around 18-19%. If needed add beet sugar to reach the required sugar content level.
You can add up to 100 grams of sugar per 1 liter of juice, but make sure not to exceed this amount—otherwise, you run a risk of stopping fermentation due to high sugar content.
Decant the juice into a fermenter, fill up to 75% of its volume. Seal with an airlock or medical glove with a hole in one of the fingers. Leave the fermenter in a dark place (cover with thick fabric) at 20-27 °C.
An example of a factory airlock and fermentation glove
Fermentation time depends on the desired characteristics of your port wine. The less you ferment the must (the minimum period is 2 days), the sweeter the port thanks to the sugars that remain in the juice.
Sweetening your homemade port wine along with fortifying it after aging is fine, as this is done to adjust the taste of the drink to your liking.
Fermentation is usually stopped when sugar content drops to 8-10%. In case you don’t have the necessary equipment to control this process, you can simply leave the wine to ferment for at least 12-15 days. The exact time depends on the fortifying alcohol.
Prior to fortifying decant the fermenting wine into another container.
Calculate the required amount of wine distillate or brandy. To do this, measure the initial potency and sugar content of the wine and then choose the final potency of your port wine (18-23%).
An alcoholometer shows the amount of alcohol right away. In order to measure the potency using a saccharimeter, you need to know the initial and final sugar content of the must and use charts provided along with the equipment. Keep in mind that 1% of fermented sugars give 0.6% potency. For example, if 12% of sugars have fermented, the final potency is going to be 7.2%. Calculate the required volume of the fortifying drink (V) using this formula:
V = wine volume * (desired potency – current potency) / (fortifying drink potency – desired potency)
You should keep In mind that higher ABV of the fortifying drink means less fortifying drink required. This positively affects the taste and flavor of the port.
If you’re using brandy as fortifying drink, it makes sense to ferment the wine until it’s fully fermented (12-14 degrees), focusing on the lower threshold of the port’s potency (18-19 degrees). In case of a potent wine distillate, there’s much more room for maneuver.
This calculation doesn’t include the volume ratio of sugar and other wine substances, as in home conditions measuring these values at least somewhat accurate is almost impossible. Just keep in mind that sugar also lowers potency.
When doing rough calculations the amount of sugar in port is usually adjusted proportionally with the change of soluble volume with the following formula:
New sugar concentration = (wine volume * sugar content * 0.01) / volume after fortifying
Once again, additional sweetening to a standard 8-9% sugar content
slightly reduces the potency and increases the gross volume. You can make a port 2-3 degrees stronger than planned by leaving a reserve for additional sugar.
In case you’re making port wine without alcoholometer and saccharimeter, measuring wine’s potency will give a very rough number: up to 20-25 fermentation days – 5-9 degrees, after 25 days – 9-10 degrees. Wine stops fermenting at about 12-14% ABV.
1Add distillate to the wine according to the calculations and sugar to your taste for sweetness. Stir. Alcohol will stop the fermentation—this is normal. Pour the prepared mixture into an oak cask and move to a cellar for 6 months. The real port wine is aged for at least 2 years.
If you used brandy to fortify your homemade port, then you can skip aging and bottle the drink—you’ve already imitated wine aging. Such port wine will also be ready no sooner than in six months. If there’s a 2-4 cm layer, filter the drink by decanting it into another container.
You can also imitate oak cask taste in an unaged distillate (well-cleared sugar or fruit moonshine are fine). To do this, you need to add 2-4 grams of oak chips per 1 liter of the drink. The time of aging depends on the concentration of tannins in the chips, potency, and room temperature. Taste the port once every 10-15 days in order to remove the oak chips in time. Otherwise, there’s a great risk of adding a strong tannin flavor.
Port wine made from red grapes. Potency – 20%, sugar content – 9%. Aged in an oak cask for 10 months.