Q: Dear Rachel,

I am struggling to assess acid, especially where there is residual sugar and high alcohol. For instance when tasting a Fino, the low body and dry style for me always makes the acid stand out. I know Palomino is a low acid grape variety so will write low/medium-, but that is not what I'm tasting. 

In a wine like these, do you have any tips/tricks for identifying the acidity level?

A: Thanks for your message. That’s a really good question. 

When we're blind tasting in exam conditions, it's important to remember that our assessment of a wine's acidity, sweetness, or other category is not just about how we perceive the wine, it's a question of recognizing and articulating its underlying qualities. So, as you mention, a wine can taste high in acidity when we know it's technically low in acidity!

When tasting a fortified wine which has very high residual sugar, it definitely becomes more challenging to determine the acidity level. For some, like a great Madeira, the acidity will sing in your mouth despite the sugar. Another clue of higher acidity is that despite the sweetness and alcohol you’re registering, the wine tastes fresh, bright, or balanced.

A sweet wine with a flabby flavour profile or lower acidity can sit heavy on the palate and taste flat, or have overwhelming sweetness or alcohol without balance.

Palomino like you mentioned, is a grape that produces lower acidity wine, and its juice is often adjusted with some tartaric acid before it undergoes fermentation - but Fino can have a bright, refreshing flavour profile, and sometimes a crisp salinity too (as in Manzanilla).

For me, the freshness that could taste like acidity comes from the biological aging/resulting acetaldehyde (AKA it smells distinctly of flor). Grapes for Fino often come from the best sections of albariza soil, plus the flor consumes glycerine, resulting in a lighter body.

With Fino, the flavour from flor will be immediately recognizable on the nose and palate, and you should ask yourself whether it’s there for each pale fortified you taste blind, so you can check in with your palate about whether the acidity is as high as it’s being perceived.

I found the analytical info for Fino and Oloroso from the Consejo website, it was curious to see Oloroso is listed as potentially having higher ranges of TA as it doesn't always taste that way on the palate!

Also of interest is this tasting article from Decanter China, in which Fongyee Walker MW suggests tasting a Fino (low acidity, high alcohol) against a Hunter Valley Semillon (high acidity, low alcohol).