In the early 1600s wines from the upper Douro were white wines. Made in the fall and shipped down to Oporto by boat during the following spring run off, they were exported to England. As weather is, well “weather”, in some years there was not enough water to float the boats. This necessitated carrying the wine over to the following spring. Wine storage not being an exact science at that time resulted in many, if not most, barrels of wine being “off”. Some unknown person worked out the fact that adding alcohol to these wines would prevent them from spoiling. It is easy to imagine that a fortified dry white wine was not all that appealing, the British had a sweet tooth, so the importers started to add sugar. For unknown reasons, red was deemed better than white, so elderberries were added for color. Due to the raw alcohol used it would not have taken long before someone worked out that age improved this concoction. Thus, we had the first “Ports”.
As a side note, in later years elderberries were considered an adulterant in the Douro, and the growing of elderberries was made illegal. In 1756 the Portuguese delimited 750,000 acres in the upper Douro valley for port production. This was the first designated grape production region in the world.
In the 85,000 Douro vineyards there are 48 different grape varieties approved for Port production; 28 red and 20 white! The three most widely used red grapes are TOURIGA NACIONAL (Cabernet Franc), TINTA FRANCISCA (French red), and TINTA CAO (Red Dog). Not so commonly grown are BORRADO das MOSCAS (fly droppings) and ESGANA CAO (dog strangler). Up until the 1940's there was a muscatel port as well as the present white, tawny, ruby and vintage ports. You can still buy muscatel port as MOSCATEL DE FAVAIOS or MOSCATEL (in small letters on the label) from Setubal.
From the only technical description that I have ever found on the subject, it stated that, by tradition, classic port is made by fortification. In a good year the red and white port grapes are picked at about SG 1.090 - 1.100 and have a TA of about 4 – 6 gm/liter. 26 gallons of 77% alcohol is pumped into the empty pipes (a pipe is 145 gallons) when a batch of fermenting must reaches a SG of 1.045 it is pumped into the pipes containing the alcohol.
The “Instituto do Vinho do Porto” (IVP) recognizes nine different port styles.
Ruby Port – A blend of three to four vintages of port, it is usually bottled at three to four years of age.
White Port – The same as Ruby, but using white grapes. They can vary in style from young, light and dry to heavy and sweet with 10 years of barrel aging. The younger dry style is a very popular aperitif in France.
Vintage Character – Blended ports of about four years of age. They must have initially had the characteristics of a vintage port.
Late-bottle Vintage – Port from a single good harvest, bottled at five to six years of age. There are two styles made. Traditional will throw sediment and require decanting. These are the best bargain as they are very difficult to tell from the real thing if aged the same length of time. The more common LBV has been filtered and are expected to be consumed as soon as you purchase them, however these do improve with aging.
Crusted – Seldom seen, this is a blend of good ports from a number of harvests. These are unfiltered and are laid down to mature, developing sediment or the crust one finds in a Vintage port. The date on a Crusted port is the date it was bottled.
Tawny – Cheap tawny is ruby port with a very high percentage of white port in the blend. Expensive tawny is a ruby port, which may have some additional white port in the blend. While they may have spent anywhere from 3 to 40 years in a barrel, they are blended and sold only as 10, 20, 30 or 40 year old tawny ports, the age being the average age of the blend.
Vintage Port – The three categories are:
Full Vintage Declaration – The most famous, but it is only about 1% of all of the port produced. This is port from a single harvest, bottled between July 1 st of the second year and June 30 th of the third year after the harvest. The proposed vintage wines are selected after fermentation and aged one year. Samples are sent to the IVP with all the production details. If the IVP agrees that the quality is worthy of a Vintage classification, the other shippers are consulted and the market conditions are studied. If there is a demand and many shippers agree, a vintage is declared. Only on very rare occasions, will one find a vintage declared by only one or two producers.
Single Quinta Vintages – Ports from a single harvest from a individual Quinta or vineyard. They are bottled the same as a Full Declaration port.
Colhieta – Single harvest tawny ports, aged in wood for a minimum of seven years. In order to make clear the difference between these wines and Full Declaration ports the label must state that the port was aged in wood, the year of the harvest and the year it was bottled.
The #1, critical, and most important item , is the quality of the quenching alcohol you purchase. The best, in my mind, is made from high acid white grapes. My feeling is that white grapes rather than red grapes produce the tastiest alcohol, but I have never run a scientific experiment. The white grapes should be Riesling, Chardonnay, etc. I would be leery of Muscat and Gewürztraminer types. Ideally the alcohol manufacturer would have acquired grapes specifically for distilling. They would have been fermented on the skins, with no sulfite and distilled as soon as the sugar is depleted, and while the wine is still full of CO2. A lower cost, not quite as good solution, is used by some manufacturers who add sugar water to the pressed white pulp (ie: a second run).
There are two kinds of stills, “pot” stills and “cracking” stills, that uses a reflux tower.
The pot still is traditional for brandy and malt delivering the most flavors. The very first alcohol that comes over is known as the “heads”. In distillates from grain the heads contain some higher, not so good alcohol and this is thrown away or added to the “tails”. Alcohol distilled from grapes show little or nothing “off” in the heads. Pot stills yield about 61% alcohol in the center-cut, when the manufacturer starts with 12% wine. When the alcohol being produced drops below about 55% this is called the “tails”.
Traditionally Port manufacturers used 77% alcohol to quench the must. They would have re-distilling the tails to produce about 90% alcohol; blend this with the center cut to yield about 77% alcohol.
Cracking stills were designed to extract all of the alcohol on the first pass and were usually designed for continuous operation rather than a batch at a time. A good cracking still yields about 90%+ alcohol in a single pass, but most or all of the flavor is lost. This is just fine in a commercial operation when you are distilling anything that will yield alcohol for gin, vodka, etc. The “cracking” part of a cracking still is the marbles, SS wool or SS screens in the reflux tower.
Remember to choose your manufacturer carefully, no amount of distilling or filtering will ever remove the awful taste of distilled junk wine. The distillation process just concentrates the off flavors and sulfite bitterness.
So, now that you have found a good manufacturer, a little math and experience shows that each gallon of 77% alcohol will require about 7 gallons of 12% wine. Using the Douro model, you will need enough alcohol to represent 18% of the total volume of port you want to make. By a happy coincidence this works out to one 4.5 gal carboy of alcohol to make a 25 gal barrel of port.
The port grapes that I prefer are BC Pinot Noir, but I have no reason to believe that they are the only possible grapes that can be used. Whatever grapes you choose, these should be ‘normal’ grapes as one would use for table wine. Remember that high pH California style grapes do not ferment cleanly, producing off flavors. As with table wines, acid should be used to lower the pH.
So, in this example I will start with x lbs. of pinot. The specs are:
SG = 1.092 or Brix = 23.5 and TA = 8 gm/l
Treat the grapes as per a normal ferment with standard yeast. I do not use sulfite, as it is my personal feeling that it is not required in port due to the high sugar and alcohol acting as a preservative and I try to avoid the bitterness caused by sulfite. The simplest and safest way of proceeding is to make a large batch of pinot, which can be used to make both the port and your table wine. I like my port to have a finished SG of 1.025, which is on the dryer side, assuming 18.5% alcohol. Thus, when the must reaches 1.051 I would rack/siphon off 20 gal, or enough to fill a 24 gal barrel, containing 4.5 gal of 77% quenching alcohol. A little extra port is handy for topping up, also as 1+1 are not equal to 2 when you mix alcohol and water, you will be about 1% short after mixing the above.
In this case my computer says that I would have met my spec requirements and that the TA would now be 6.6 gm/l due to the alcohol dilution.
Remember that in a pinch, one can stop the ferment with only enough alcohol to cause the ferment to stick, about 14% or 3.8 gal at this sugar level. You can then top up the barrel with the balance of the alcohol required at a later date. Naturally it is better and safer to do it right.
Left to its own devices the alcohol will all float to the top and fermentation will continue at the bottom of the container. Thus, it is very imPORTant to rack on to the alcohol plus do some vigorous stirring to completely mix the two liquids.
It seems pretty standard that the must will drop through the quenching point around 3:00 am in the morning! At this point in the fermentation process the must can easily be dropping at more than .001 SG/hr, so a very close watch is required. A simple backup procedure is to refrigerate a few gallons of the original fresh juice. If it is not required to adjust the port it can simply be dumped back into the table wine must.
This port making procedure quite possibly improves the quality of the table wine as one is fermenting on twice the normal amount of skins.
Color has not been problem for me. Vintage ports are very often not all that dark. If you decide that the color is too light, topping up with a very dark table wine will solve your color problem. The only word of caution is that ports should have little or no tannin, so use low tannin wine or you may have to fine the port with gelatin. High tannin is the major problem with 99% of the ports that I judge in competitions, and the solution is so simple; fine with gelatin!
Quite high acid grapes have worked just fine. Between the dilution of the quenching alcohol and the dropping of extra acid due to the high alcohol, the acid sugar balance always seems to work out to perfection.
Barrels should not be new. Vintage port has no noticeable oak flavor. Due to the high alcohol, the port settles out to crystal clear very quickly, 2-3 weeks.
The above method produces a classic port, and in Portugal when everything is perfect it becomes a vintage port. When the grape sugar or acid is off spec or they missed the quenching point, it is blended across the years to become a ruby port. Vintage ports are relatively rare, thus we can infer that all of the conditions are not met, or there is no market, most years.
In general, I have found that the grapes never meet the perfect spec., the alcohol I have purchased is not 77% and the quenching point is going to happen at a very awkward time. So, I have developed a rather elaborate computer program that I enter all of the variables into, it then tells me what to do & when! I would distribute it, but unfortunately it was written in PlanPerfect and does not work well (or at all) running under Windows. However, all you need to do is give me a call with your numbers and I can run the program for you.
A recent example using BC Pinot Noir and the Douro model, produced the following.
Starting spec’s: SG 1.093, TA 9.1 g/l, pH 3.5 with 65% alcohol available.
Computer model spec’s. Quench 20 gal at 1.052 with 27 liters of 65% would yield SG 1.025, TA 7.3 g/l & 18% alcohol.
Later added 1.5 litres of 62% to raise to 18.6% alcohol.
Todays spec’s: SG 1.026, TA 5 g/l, pH 3.5.
I find that the pH rarely changes, so a good starting pH results in a good finished pH.