One of the great contributors to whisky flavour is the selective aging (or “finishing”) in oak casks that previously held other spirits or wine. One of my favourite types of finishing involves the fortified wine known as Port (or Porto, for the region in comes from).

You don’t need to understand Port varieties to enjoy whisky finished in this way. But I had to chance to visit Portugal recently, and had the privilege to sample some really excellent Port. In researching for my trip, I discovered that classifying Port is actually a fairly complex undertaking, and that a lot of online Port resources are either incomplete, inconsistent, or somewhat confusingly presented. So I thought I would provide a primer to help you understand how Port is made, what the different types of Port represent, and what characteristics this may impart in your whisky.

What is Port?

Port is a fortified wine, which means that additional spirit has been added to a wine, raising its alcohol content.

By European Union Protected Designation of Origin definition, Port is designated as originating only in Portugal. Port has been produced in the Douro Valley region of northern Portugal for centuries. A number of countries produce a similar style of fortified wine, and may use the “port” term more generically – but this primer is specific for Port from Portugal.

Like all wine, Port is naturally fermented – but the fermentation process is halted in Port before the residual fruit sugar is exhausted by adding a neutral grape spirit called aguardente (similar to brandy). As a result, this leaves a relatively sweet dessert wine (although it can come in dryer forms).

Port ranges between 19-21% ABV. It keeps well while sealed in the bottle, but will break down once opened and exposed to air – not as quickly as regular wine, but it is certainly nowhere near as stable as whisky. But it is a little more complicated depending on the type of Port we are talking about. I will give some guidance for storage for the different types of Port below (you may also want to check out my guidance on whisky storage here).

How is Port made?

Port can be made from both white and red grapes (though predominantly red grapes are used for most Ports). There are about a hundred grape varietals that can be found in different blends of Port, but the five key grapes used for the vast majority of Port are Touriga Nacional, Touriga Franca, Tinta Roriz (aka Tempranillo), Tinta Barroca and Tinto Cão.

All Ports commercially available are blends of different grapes, from multiple vineyards under the control of a given producer (known in the biz as a Port “Shipper”). So the distinctiveness comes more in the processes used to prepare and age the Port at the various shippers.

After the grapes are picked, they are either stomped by foot in stone tanks (the traditional method – still sometimes offered to tourists willing to roll up their socks and jump in), or more commonly today, crushed mechanically in large stainless steel tanks. They are left in the tanks for 1-4 days, where the naturally occurring sugars are converted to alcohol through fermentation. When about half of the sugar is used up, neutral grape spirit is added to prematurely stop fermentation (by killing the yeast). It is then transferred to large stainless steel tanks or wooden casks to age for a minimum of two years. After that, the Ports are directed down different paths, depending on their quality, into various types of final Port products – which I will describe below.

How many types of Port are there?

This is where things start to get a little complicated.

If you wanted to classify Port types the same way we do for wine, you could separate Ports into white or red, based on the types of grapes used. Red grapes are dominant here, and used to produce Ruby Port (typically bottled and drunk fairly young) and Tawny Port (similar to Ruby, but aged in wooden casks to accelerate aging and oxidation, and drunk soon or after longer times in the bottle). There is also a rare style, Garrafeira Port, which has characteristics of both – which I got to sample on my recent trip and will explain later in this article.

But most Port enthusiasts differentiate Port a little differently, and segregate Port into two main types based on whether they are wood-aged or “bottle-aged.” Now, that latter category is going to take some explaining for a whisky drinker. Port is not a distilled product like whisky, but behaves more like wine – and so, a different type of reductive “aging” can happen in the closed bottle, and is influenced by how the Port has been prepared and stored, especially whether or not it has not been “fined” or filtered first (I’ll explain these terms in the discussion of Vintage Port, below).

Coming as a whisky drinker, you could also choose to break it down by no-age-statement (NAS), age-stated or single-year vintages. That last category is surprisingly complicated for Port, for the variable “bottled-aged” reasons mention above (e.g. all “Vintage Ports” are a single vintage, but not all single year vintages are Vintage Port). I know, it is confusing. So I’ll cover each of these NAS, age-stated and vintage types in turn, under the general categories of the two main types of red Port, Ruby and Tawny.

Again, it is important to note that Ruby and Tawny are not differentiated by the types of red grapes involved. Instead, it is the type of aging that matters, with the latter receiving a lot more time in wood (spoiler alert: that extra wood aging is what turns a “ruby” coloured red port into a more “tawny” coloured one).

Ruby Port

This is probably the best place to start, as Ruby is the most basic form of Port – and typically the youngest.

After fermentation, Ruby Port is typically stored in large tanks of concrete or stainless steel instead of wood, to minimize oxidative aging and preserve its colour and fruitiness. A standard Ruby Port is a blend of several years, typically averaging 3-5 years old. They are relatively simple and straightforward, very fruit-driven (with bright, fresh fruit notes), and meant to be drunk as soon as they are bottled. The name is derived from the bright red colour of the final Port (think cherry or cranberry juice). Indeed, I find the sharp flavours of fresh cherries, cranberries and raspberries come through most prominently on Ruby Port.

Standard Ruby Port is fined and filtered before bottling (see below for explanation of these terms). Once opened, they last a reasonably long time (i.e., weeks to months before obvious degradation sets in). And even then they are still quite drinkable – so there is no rush to finish the bottle. Indeed, open bottles of Ruby Port are often used for cooking, like inexpensive Sherries.

A “Reserve Ruby” Port is typically a bit older, 5-7 years on average. They are still very fruit-forward Ports, but have a bit more complexity due to the extra aging time. A 10 year old Ruby Port represents a blend of Rubies that are 10 years old on average. A good Reserve or 10 yo would be my preference among basic Ruby Ports.

Specific vintages are where things get a bit more complicated. The main types to differentiate are Late Bottled Vintages (LBVs) and “Vintage Port” (VP) – which are both protected definitions, and both involve some wood cask aging.

Late Bottled Vintage (LBV) Ports

Something you see a lot more of now is “Late Bottled Vintage” Ports (LBVs). These are specific vintages of Port, with the grapes were all picked from a single harvest year. LBVs are bottled between 4-6 years after harvest, and typically spend those years in very large oak barrels, called Tonnels. LBVs may have started their lives intended to be Vintage Ports (see below), but due to reduced demand or over-supply were kept aging longer and directed down the LBV line. They come in two types and can be either filtered and fined (like your typical Ruby Port) or unfiltered (where residual material from the grapes remains in the bottle). Again, I’ll explain all that in the discussion on Vintage Port below.

For now, a simple way to tell the difference is that fined and filtered Ports typically come sealed with a standard T-shaped stopper cork (like whisky bottles), and can be poured and enjoyed straight from the resealable bottle (example pictured on the right). Unfiltered LBVs typically have a driven cork (like wine bottles) and possess considerable sediment – and so will need decanting prior to drinking.

Unfiltered LBVs should ideally be drunk within a few days after opening, but a week will likely be fine. Filtered LBVs are more like aged Rubies and can probably go a few weeks with no obvious change (especially if refrigerated after opening).

FYI, LBVs have largely replaced the so-called “Crusted Ports”, which were blends of at least two or more vintage years that were aged in wood for up to four years, bottled unfiltered, and then aged for a few years before release.

Vintage Port

Along with the aged Tawny Ports (covered below), “Vintage Port” is often seen as the pinnacle of quality Port among aficionados and enthusiasts.

Note that the phrase Vintage Port (VP) has a very specific meaning that is carefully controlled by EU law. VPs start down the path to this designation very early, when the Port shipper petitions for this status for a given harvest. On average, VPs are only produced ~3 times a decade – typically representing the very best harvest years.

Batches of a specific harvest destined for VP status are stored in stainless steel or heavily-used oak barrels – but only for 2-3 years. These two features help limit the impact of any wood aging. Indeed, by law, VPs must be bottled between 2-3 years after harvest.  But they are always bottled unfined and unfiltered, to ensure that the maximum possible amount of “bottle aging” can occur.

I know that concept is going to sound odd to whisky drinkers, as there is no real “aging” going on in a factory-sealed whisky bottle (see my overview of the whisky process here). But that reflects the high-proof and complete air-proof seal of a whisky bottle. Wine is still a living product that continues to evolve in the bottle.

I need to finally explain the role of fining and filtering in Port (or for that matter, any wine). There is a rough analogy to whisky chill-filtering here, but not exactly. Fining involves adding a substance to the wine during production to remove suspended particles that cause haziness or clouding, or form unwanted sediment. This fining agent isn’t bottled with the wine – instead, it is left to adhere to particles in suspension, and then settles as sediment in the bottom of the vat (where it will get filtered out before bottling).

Fining is used mainly to stabilize and clarify wood-aged Ports, to ensure they remain bright and visually attractive to consumers (i.e., like chill-filtering in whiskies). But it also limits reactivity over time, as you are removing a lot of the left-over grape material that can break down and change the flavour with time. Fining is also used to make wines “softer” and less harsh, by removing tannins.

In the case of Vintage Ports (and some LBVs), you are leaving that unfiltered grape material – and the eventual sediment – behind in the bottle. Over time, it will change the flavour of the so-called “bottled aged” Vintage Port. VPs are actually expected to be cellared for many years (e.g., 30+), to ensure maximum maturation. Indeed, much of the character of aged VP comes from the continued slow decomposition of those residual grape solids in the bottle. Given the increasing amount of sediment that will form over time, these VPs must be decanted prior to drinking.

The flavours of VPs are very diverse, and highly dependent on the source harvest, the Port shipper’s processes, and the amount of time spent in bottle – but largely independent of any significant wood influence. I’ve had some >30 yo VPs that still taste relatively “fresh”, with classic Ruby notes – whereas others can seem quite a bit more “seasoned” in comparison (and closer to some wood-aged Tawny Ports, as explained below). Two examples that I sampled on this visit were a Ferreira 1985 VP and a Borges Oporto 1980 VP (shown in the side pictures), which were very, very different beasts.

As mentioned, VPs are always bottled with a driven cork. So for an aged VP, you really should finish the bottle within 2-3 days after opening. Younger VPs (i.e., under 10 years old) should be able to last a couple of days longer before noticeable degradation occurs. But this style of Port is going to have a very short life once the bottle is opened.

There are a few more types of VPs out there, such as Single Quinta Vintage Port (SQVP), where the grapes all come from a single property (similar to a single vineyard wine). But these are actually less distinctive that typical VPs, as the SQVPs can come from any harvest, not just the premium ones declared for VPs.

It is important to note that LBVs, SQVPs and VPs are not the only kind of specific vintage/harvest Ports out there – but they are the main types coming from the Ruby Port pathway.  For other examples, it is time to turn our attention to Tawny Ports.

Tawny Port

This is the form of Port likely most familiar to whisky drinkers – indeed, it is the most popularly consumed type of Port.

Tawny Port actually starts out just like a Ruby Port, but then spends an extended period of time in oak casks. These are the classic, large oak casks known as “Port Pipes” (~550 liter volume). Like Sherry Butts, quality Port Pipes are heavily sought after for finishing whisky. The somewhat porous oak (and significant air headspace) allows for extended air exchange over time, helping to mature and oxidize the Port in the cask.

In keeping with this oxidative process, the colour of the Port wine slowly changes from the bright red of a “ruby” to the reddish-brown “tawny” colour. The more time Port spends in wood, the “tawny-er” it becomes (and the more complex its flavour profile). Indeed, here in Canada, the word “Tawny” is allowed to be used for any Port-style fortified wine aged in wood, not just those originating in Portugal.

I find the fruit notes in Tawny Port move more toward softer blueberry and grapey fruit flavours, while other “woody” notes come in – including commonly nuts, caramel and chocolate, among others.

A standard NAS Tawny Port is likely a couple of years older at the time of bottling than an entry-level NAS Ruby Port. It should last without obvious degradation for several weeks to months once it is opened (especially if refrigerated). A Reserve Tawny is typically aged for at least 7 years, and similarly has a good shelf life.

While there are some vintage-specific Tawny Ports (which I will explain in a moment), it is more common to see age-stated Tawny Ports available out there.

Tawny Port Age Statements

Unlike whisky, where age statements can be any given age, there are only 4 approved age statements in Tawny Port: 10, 20, 30 and 40 years old.

Like whisky, these are blends of many years/harvests, chosen to present a distinct “house style” for that particular Port shipper. The Master Blender of each Port shipper will take great care to produce a style that they can reliably recreate across batches – just as whisky makers try to do for their core age-stated ranges.

Unlike whisky however, the stated age on the Tawny Port bottle is not the minimum age for each Port that went into the blend, but rather the average age of Ports in the bottle. Or more accurately, the minimum average age (i.e., a good Master Blender is likely to aim for a slightly older average than the minimum 10, 20, 30 or 40 years listed on the bottle, to give themselves flexibility in keeping a consistent style over the years).

So that 30 yo Tawny Port could easily have a balance of 5 yo and 50 yo Ports in the bottle (plus all ages in-between). Aged Tawny Ports are really my jam – quite literally, given the more stewed flavours you often find in these Ports.

Younger age-stated Tawny Port should also last without obvious degradation for several weeks to months once opened (especially if refrigerated). As a general rule though, older Tawnies will not last as long as younger ones once opened, so you should try to drink them more quickly.

There is a view out there in some quarters that Tawnies will not last as long as Rubies once opened, given that they have already been extensively aged in the presence of air. But the more common competing view is that they are more resistant to major age degradation effects once opened, due to their already extensive aging. I don’t have enough experience to come down on one side of the issue or the other – and I am not likely to leave an open bottle lying around long enough to find out which breaks down faster anyway!

For Tawny Port fans, age-stated bottlings are probably the best trade-off for quality for price. Around here, 10 yo Tawnies are usually not much more expensive than standard NAS or Reserve Tawny. 20 yo Tawnies are probably the sweet spot in terms of price-performance, going for about twice the price of 10 year olds, but with a lot more character and flavour. In contrast, 30 yo and 40 yo Tawnies are heavily over-priced for the quality, and so likely not worth the extra cost to most. But that leads me to a special class of single harvest Tawnies that you may want to consider instead, known as Colheitas.

Colheita Ports

Colheita (pronounced Col-YATE-a) is basically a single vintage-dated Tawny Port, but one typically aged in small, well-used oak barrels instead of the large Port Pipes of most Tawnies. Colheita Ports must be aged in wood at least 7 years, but can spend quite a bit more time.

Just like Vintage Port (see above), Colheita single harvest years are “declared” after approval by the IVDP (Port and Douro Wine Institute). So, this means you should be getting a particularly good single harvest (although that will depend on the particular Port shipper). But as a result, production volumes are low. These aren’t widely produced, and so are not commonly available outside of Portugal at the moment.

But that is a shame, as they can represent extraordinary value. On my recent trip, I found that the >15 yo vintage Colheitas from the Port shippers who specialize in this style to be particularly nice, and no more expensive that a standard blended 20yo Tawny. In one particularly good deal, I brought back an outstanding 1974 vintage Colheita from the premium Port Shipper Barros, bottled in 2019 (so, ~45 years old) that cost $145 CAD. That is less than half what a typical blended 40yo Tawny costs around here. Not bad for a single harvest vintage!

Labeling can be a bit inconsistent on these, depending on the Port shipper. You will probably find “Colheita” on the front or back label (but not always), along with the harvest year (on the front) and bottling year (typically on the back). Look as well for “matured in wood” or “aged in cask” on the labels, to help differentiate from LBVs or other vintage Ruby Ports.

In terms of how long they last once opened, it is a similar story for other Tawnies of equivalent age – younger ones (i.e. <20 years) should last for several weeks to months without obvious degradation (especially if refrigerated). Heavily aged Colheitas should be drunk quicker, for best results.

And now for the last defined Port type I will consider, the ultra-rare (but very rewarding) Garrafeira Port.

Garrafeira Port