Acidity: the reason wine can feel fresh

Freshness is not a flavour. Much of the time, it is structure

Wine people use words such as:

fresh.

crisp.

bright.

zippy.

taut.

Those words often point towards acidity.

Not always.

But often enough that acidity is one of the first structural things worth learning to feel.

The good news is that you do not need to know the chemistry before you can recognise it.

Your mouth gives you a clue.

What acidity actually is

Wine contains several acids.

Tartaric and malic acid come principally from the grape. Fermentation and bacterial activity can create or transform other acids.

You do not need to memorise the list.

The useful point is that acids contribute to the sour or tart part of wine's structure.

They also affect wine chemistry in ways that matter for stability and ageing.

For the drinker, however, the first job is simpler:

notice what acidity feels like.

Your best clue is saliva

Take a sip.

Then pay attention to what your mouth does after you swallow or spit.

Does it start watering?

Does that salivation continue for a while?

Higher-acid wine tends to provoke more of that mouth-watering response.

That is a more useful clue than trying to decide whether the wine smells of lemon.

A low-acid wine can smell citrusy.

A high-acid wine can taste of ripe fruit.

Flavour vocabulary and structure are related, but they are not the same thing.

What changes acidity?

Grape variety

Some varieties commonly retain more acidity than others.

Riesling, Chenin Blanc, Sauvignon Blanc, Albariño, Sangiovese and Nebbiolo are useful examples of grapes where acidity often matters structurally.

Ripeness and climate

As grapes ripen, their acid balance changes.

Broadly, cooler growing conditions and earlier picking can preserve more acidity, while warmer conditions and greater ripeness can reduce it.

That is a tendency.

Altitude, night temperatures, variety, vineyard decisions and vintage can complicate the picture.

Winemaking

A winemaker can alter the acid profile too.

Malolactic conversion changes malic acid into lactic acid.

The result often feels rounder or softer.

Winemakers may also adjust acidity where regulations allow.

So even acidity is not simply “what the vineyard gave us”.

The key variable: what is acidity sitting next to?

Acidity does not act alone.

This is where many misunderstandings begin.

Sugar

A wine can have high acidity and still taste sweet.

Sugar changes how prominent the acidity feels.

That is why a sweet Riesling can remain startlingly fresh.

Alcohol

Alcohol can create warmth or heat.

That can sometimes be confused with sharpness, but it is a different sensation.

Temperature

A warmer wine can feel broader and softer.

Chilling can make freshness feel more obvious.

Tannin

In red wine, acidity and tannin can both make a wine feel firm, but they do different things.

Acidity encourages salivation.

Tannin dries and grips.

Learning that difference is one of the most useful tasting skills you can build.

What people often misunderstand

High acid does not mean dry

Sweetness and acidity can exist together.

High acid does not mean better

A wine can be painfully sharp, beautifully balanced or somewhere in between.

More is not automatically superior.

Acidity is not the same as citrus flavour

Lemon or green-apple aromas may suggest freshness, but they are not measurements of acid.

Low acid does not mean bad wine

Some wines are naturally broader and softer.

The question is whether the structure works as a whole.

Try this

Taste two contrasting white wines side by side.

For example:

a high-acid Riesling or Chablis

and

a softer, fuller Viognier or a riper Chardonnay.

Ignore aroma for the first sip.

Concentrate only on what happens in your mouth afterwards.

Which one makes you salivate more?

Which feels softer?

Then go back and smell them.

Separating structure from aroma makes both easier to understand.

Worth knowing

Acidity and pH are related but they are not the same measurement.

You do not need either number to enjoy a bottle, but it is useful to know that “acid” is not one single laboratory figure hiding behind the word fresh.

Read next

• Riesling
• Sangiovese
• Why wine tastes the way it does
• Dry, sweet and everything people misunderstand between them