# Bottle & Context — full text

> Bottle & Context is an independent adult wine-literacy publication about labels, styles, and comparative tasting. It is not a wine shop, bar, station, restaurant, producer, importer, certification provider, booking service, or continuation of any former business associated with this domain.

# How to Compare Two Wines Side by Side

> Compare two wines by choosing one question, serving small equal pours in matching glasses at the same temperature, and hiding labels to reduce brand bias. Note appearance, then smell each wine before and after swirling. Taste structure—sweetness, acidity, tannin where relevant, body, alcohol warmth, flavor intensity, and finish—before deciding preference. Revisit the first wine after the second because order changes perception. Write observations before revealing producer, origin, vintage, alcohol, and price. Provide water, food, and a spit cup, make unfinished pours normal, and ensure nobody tasting drives afterward.

Source: https://richmondwinestation.com/compare-two-wines-side-by-side/  
Publisher: Bottle & Context  
Published: 2026-07-19  
Updated: 2026-08-26

## Choose one question and two wines

A side-by-side tasting teaches more when the comparison has a reason. Choose two wines differing in one useful dimension: the same grape from two regions, the same region from two vintages, an oaked and unoaked style, or two price points bought from the same trustworthy retailer.

Do not pretend every other variable is controlled. Producers, farming, winemaking, bottle age, storage, and closure may differ too. The question is “What differences can I describe here?” rather than “Which continent has won wine forever?”

This is an adult tasting, not a drinking challenge. Use small pours, provide water and food, offer a spit cup, and make it normal to leave wine unfinished. Nobody tasting should drive or perform safety-critical tasks afterward.

## Keep the setup fair

Use two clean glasses of the same shape for each person when possible. Label them A and B. Pour similar small amounts and serve the wines at the same appropriate temperature. Excess warmth can make alcohol more prominent; excessive cold can mute aroma and texture.

Avoid strongly scented candles, perfume, cooking smoke, or cleaning products. Use neutral light and a plain pale background for looking at color. Have water and plain bread or crackers available, understanding that any food can affect perception.

If reducing label bias matters, ask someone not tasting to bag or cover the bottles and record which is A. A blind comparison hides identity, not your own expectations, glass differences, or the room's enthusiastic garlic.

Read [wine labels without guessing](/read-wine-label-without-guessing/) after the first notes, then compare what the disclosed origin and style help explain.

## Look before inventing a verdict

Tilt each glass over the pale background. Note color family, depth, visible bubbles, haze, or sediment without treating every difference as quality. Unfiltered or aged wine may show deposit; unexpected haze or fizz may also warrant checking the producer or retailer.

Use relative language: A is paler than B; B has more visible bubbles; both appear clear. Do not claim grape, age, or fault from color alone. Appearance creates hypotheses, not a passport scan.

The Wine & Spirit Education Trust describes systematic tasting as moving through [appearance, nose, palate, and conclusion](https://www.wsetglobal.com/knowledge-centre/blog/2026/how-to-train-your-palate). This guide uses that broad sequence without reproducing WSET's proprietary tasting materials.

## Smell in two rounds

Smell each glass without swirling. Note intensity and one broad family: fruit, flower, herb, spice, earth, toast, or something else. Then swirl gently and smell again.

Move from broad to specific only when the memory feels real. “Citrus” is a useful observation; “lemon peel” is useful when that is genuinely what it recalls. A friend saying grapefruit does not make your lemon wrong. Aroma description connects sensation to memory, and memories do not share one filing cabinet.

If a wine smells sharply unpleasant, musty, vinegary, or otherwise wrong, pause. Compare with a knowledgeable retailer or producer rather than diagnosing every unfamiliar aroma as a fault.

## Taste structure before flavor poetry

Take a small sip, move it around the mouth, and spit or swallow according to your plan. Note:

- apparent sweetness;
- acidity or mouthwatering freshness;
- tannin and drying grip in red or skin-contact styles;
- body or weight;
- alcohol warmth;
- flavor intensity and families;
- finish after the wine leaves the mouth.

Compare one dimension at a time: “B feels more acidic than A” is clearer than “B is much more elegant.” Preference comes later.

Rinse with water and pause between wines. Revisit A after B because order changes perception. If your impressions reverse, record that rather than choosing the first note out of loyalty.

Browse [tasting practice](/tasting-practice/) for more controlled comparison prompts.

## Reveal the labels after writing

Before uncovering bottles, finish two short notes:

> **A:** pale; moderate citrus and herb aroma; higher perceived acidity; light body; short clean finish.  
> **B:** deeper color; ripe fruit and toast aroma; lower perceived acidity; fuller body; longer warm finish.

These are structural examples, not promised characteristics of a grape or region. Then reveal the labels and record producer, wine name, origin, vintage, alcohol, price paid, purchase date, and storage context. Look for explanations, but do not rewrite your senses to flatter the prestige label.

Continue through [label literacy](/label-literacy/) when a term needs a regulatory definition.

## End with usefulness, not a winner

Ask which wine you prefer today, with what food or occasion, and why. One may suit a meal while the other works alone; one may offer better value at the price you actually paid. “Different jobs” is a legitimate conclusion.

Recork or close unfinished bottles promptly and refrigerate them; preservation time varies with style, oxygen exposure, closure, and storage. If a wine seems spoiled, do not use tasting as a dare.

The valuable output is a reusable sentence: “I preferred A because its higher acidity balanced the food,” not “A received 93 points from the dining table.” Your table has not filed its judging credentials, and that is freeing.

## Frequently asked questions

**Which two wines should a beginner compare?**

Choose wines with one clear contrast: the same grape from two regions, the same region from two vintages, an oaked and unoaked example, or two prices from a trustworthy seller. Keep color and broad style reasonably similar on a first attempt. Producers and production will still differ, so frame the result as a comparison of these bottles, not proof that one region or grape is universally better.

**How much wine should I pour for a comparison?**

Use a small, similar amount in each glass—only enough to smell, sip, and revisit. The precise volume is less important than equal conditions and responsible total service. Provide water, food, and a spit cup, and normalize leaving wine unfinished. Follow local alcohol laws and personal guidance. Anyone driving, operating equipment, swimming, supervising safety-critical activity, pregnant, in recovery, or medically advised to avoid alcohol should not taste.

**Should wines be compared blind?**

Covering the bottles can reduce influence from brand, price, region, and label design, making it easier to record the glass before reading the story. It does not control temperature, glassware, order, storage, or personal expectations. Blind tasting is optional. Whether labels are hidden or visible, write observations before discussing them and reveal identity only after both notes are complete.

**What should I write in a wine tasting note?**

Record appearance briefly, then aroma intensity and families. On the palate, compare apparent sweetness, acidity, tannin where relevant, body, alcohol warmth, flavor intensity, and finish. Use relative, plain language such as “B is more acidic than A.” Add preference and context afterward. Include producer, wine, origin, vintage, alcohol, price paid, purchase date, and storage context after the label reveal.

**What if two people smell different things in one wine?**

That is normal. Aroma descriptions connect volatile compounds with personal memory, language, attention, and sensitivity. Start with broad families, then become more specific only when the association feels genuine. One person may say lemon while another says grapefruit. Compare intensity and structure as well as names. A shared vocabulary can improve communication, but agreement is not required for either person to make an honest, useful note.


---

# Cork vs Screw Cap Wine: What the Closure Tells You

> Neither cork nor screw cap establishes wine quality. Compare opening convenience and the producer's guidance for the specific wine; closure alone cannot predict ageing. Reclose opened still wine and refrigerate it upright. This is adult wine literacy, not encouragement to drink. Avoid alcohol during pregnancy, before driving or safety-critical tasks, and when recovery or medical advice requires abstinence. Ask a pharmacist about uncertain medication interactions. Do not drink from damaged glass.

Source: https://richmondwinestation.com/cork-vs-screw-cap-wine/  
Publisher: Bottle & Context  
Published: 2026-09-07  
Updated: 2026-09-07

## Is cork or screw cap better for wine?

Neither cork nor screw cap proves that a wine is better. A screw cap offers convenient opening and resealing; cork may suit a preferred presentation. For keeping a bottle, ask about the particular wine and closure, not just the material you can see. This guide covers commercially bottled still wine for adults of legal drinking age. Learning about packaging does not require drinking.

The useful question is not whether one closure deserves the nicer tablecloth. It is what the closure does, what evidence supports a claim about it, and whether that matters for your bottle.

## What does each closure actually do?

A closure seals the bottle. In a screw cap, the metal shell holds a lined disc against the glass rim. The liner helps determine how much oxygen can pass through; different liners need not behave identically. The Australian Wine Research Institute's [screw-cap explanation](https://www.awri.com.au/industry_support/winemaking_resources/storage-and-packaging/packaging-operations/applying-screw-cap-closures/) describes both the sealing system and differences in oxygen transmission.

That makes “all screw caps are completely oxygen-proof” a poor shopping rule. Equally, the word cork does not tell you every detail of a stopper's construction or performance. Ask for the producer's closure specification if that detail matters; a photograph of the bottle neck is not the specification.

| Question | Cork-stoppered still wine | Screw-capped still wine |
|---|---|---|
| What opening equipment should I plan for? | A suitable corkscrew, used according to its instructions | Ordinarily no corkscrew |
| Does the closure certify quality? | No | No |
| What should I ask before keeping it for years? | The producer's guidance for this wine and closure | The same wine-specific question |
| What about after opening? | Reclose and refrigerate upright | Reseal and refrigerate upright |
| What if the bottle is damaged? | Do not serve from damaged glass; contact the seller | The same precaution applies |

These are reader-facing distinctions, not a laboratory ranking. We have not conducted a closure trial or tasted bottles for this comparison.

## Does a screw cap mean cheap wine?

No. WSET's [guide to choosing wine](https://www.wsetglobal.com/knowledge-centre/blog/2025/how-to-find-a-wine-youll-like) explicitly separates closure type from overall wine quality and notes the practical convenience of a cap that can be resealed.

Our editorial advice is to put the closure behind more useful questions: Is this the style the recipient wants? Is the producer's description specific? Can the seller explain the bottle's condition and intended use? Does the actual price fit your budget?

Consider an illustrative gift decision, not a product recommendation. You have identified a wine the recipient enjoys, but it has a screw cap. The alternative has a cork and an unfamiliar style. If your only reason to switch is that cork looks more expensive, you are replacing evidence about their preference with a packaging assumption.

The reverse applies too. Someone may enjoy the presentation of a cork-stoppered bottle. That is a legitimate preference, provided it is described as presentation rather than proof of better wine. Confirm that an alcohol gift is welcome before choosing either.

## Can wine develop under screw cap?

The closure question deserves more than “cork breathes.” AWRI's current overview describes research following a 1999 Semillon under different closures over ten years. Bottle development under screw cap is therefore a subject of measured observation, not an impossibility.

Read old comparisons carefully, however. In its [first trial report, published in 2001](https://www.awri.com.au/information_services/media-releases/2001/07/12/first-results-of-the-awri-wine-bottle-closure-trial-published-12-july-2001/), AWRI described one Semillon bottled using 14 closure types. The screw-capped samples retained the most sulfur dioxide and ascorbic acid and browned most slowly; a rubber-like aroma was reported after 18 months. No closure satisfied every assessed long-term criterion in that initial report.

That is evidence of trade-offs in a particular experiment. It is not a present-day ranking of every cork, cap, grape or vintage. It also does not establish that your bottle will improve if you keep it.

Before setting a bottle aside, ask the producer or knowledgeable retailer:

- Is this particular wine intended for keeping, or for its current style?
- Does the advice apply to the vintage and closure actually supplied?
- What storage conditions does that recommendation assume?
- What change is expected, and would that change suit your preference?

Record the answer with the bottle identity. If the seller offers only “it has a cork,” the original question remains unanswered. Our [wine-label guide](/read-wine-label-without-guessing/) helps capture the producer, wine name and vintage accurately.

## Can screw-capped wine be corked?

“Corked” usually means cork taint, not visible crumbs of cork. AWRI identifies 2,4,6-trichloroanisole, abbreviated TCA, as a major cause of musty wine aromas and explains that contamination can occur without contact with cork, including through oak. A screw cap therefore does not establish that every possible source of TCA has been excluded. See its [wine-taints reference](https://www.awri.com.au/industry_support/winemaking_resources/sensory_assessment/recognition-of-wine-faults-and-taints/wine_faults/).

WSET's [fault guide](https://www.wsetglobal.com/knowledge-centre/blog/2023/august/24/common-wine-faults-and-how-to-spot-them) distinguishes cork fragments from cork taint and notes that people differ in their sensitivity to musty characteristics. This is useful vocabulary for describing a concern, not a requirement to diagnose the chemistry.

If a bottle seems wrong, stop serving it and contact the seller. Keep the bottle identification and purchase details. Describe what you noticed and ask about the return process; do not promise yourself an exchange before checking the policy. Do not repeatedly taste a suspect bottle to prove a fault.

If glass is cracked, chipped or broken, do not drink the contents or attempt to filter them for consumption. That is a physical safety issue, separate from whether the wine smells musty.

## Does resealing restore an unopened bottle?

No. Resealing limits further exposure but does not reverse the fact that the bottle has been opened.

For opened still wine, WSET recommends [upright storage and refrigeration](https://www.wsetglobal.com/knowledge-centre/blog/2023/march/07/the-best-ways-to-preserve-wine-after-opening), including for red wine. Cooler storage slows oxidation. A cap's convenience does not make an opened bottle immune to change.

Write the opening date on a removable label and close the bottle promptly after pouring. Follow any more specific producer instructions. We do not assign a universal usable-life guarantee based on cork versus cap: the wine and what happened after opening matter too.

Do not finish a bottle simply to avoid leftovers. Choosing not to drink, leaving wine unfinished or declining an alcohol gift requires no justification.

## How can you compare closures without inventing a result?

Start with a desk comparison of producer information. Make a short record for each bottle: exact identity, closure as stated, intended storage, opening requirements and the unanswered question. Mark missing information “not supplied,” rather than filling it from a general impression of the region.

For example, if one technical sheet names a closure and another gives only a photograph, record different levels of documentation. Do not convert that difference into a score for wine quality.

Even an optional [side-by-side tasting](/compare-two-wines-side-by-side/) of two unrelated wines cannot isolate the closure's effect. Different wine, vintage or storage history introduces other explanations. A useful conclusion might be “the cap was more convenient for this setting.” “Screw caps make wine taste better” would exceed what that comparison could show.

Alcohol precautions apply regardless of packaging. Do not drink before driving or safety-critical activity, during pregnancy, or when abstinence is part of recovery or medical advice. NIAAA states that there is [no known safe amount during pregnancy](https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/alcohol-and-your-pregnancy). If medication interactions are uncertain, avoid alcohol and [ask a pharmacist or other healthcare provider](https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/harmful-interactions-mixing-alcohol-with-medicines).

## Sources

- Australian Wine Research Institute: screw-cap construction, the initial closure trial report, and wine-taint reference, linked above.
- Wine & Spirit Education Trust: closure and quality distinctions, wine faults, and opened-wine storage, linked above.
- National Institute on Alcohol Abuse and Alcoholism: pregnancy and medication precautions, linked above.

## Frequently asked questions

**Is screw-cap wine lower quality than cork-stoppered wine?**

No. Closure type does not establish overall quality. Consider the specific wine, condition and recipient's preferences before packaging. A screw cap may be convenient, while a cork may suit someone's preferred presentation. Neither feature alone shows that the contents are better or worth a higher price.

**Can wine change as it ages under screw cap?**

Yes. AWRI has studied development under screw cap, but evidence from a particular wine and closure is not a guarantee for every bottle. Ask the producer about your exact wine, vintage, closure and storage conditions. Keeping a wine longer does not automatically mean that you will prefer it.

**Does corked wine mean there are bits of cork in it?**

No. Cork taint describes an aroma problem commonly associated with TCA, not simply fragments of a stopper. Wine can have TCA contamination without contacting cork. If a bottle seems wrong, stop serving it and ask the seller about assessment and returns rather than repeatedly tasting to confirm a diagnosis.

**Should opened screw-cap red wine go in the fridge?**

Yes. Reclose opened still red wine and refrigerate it upright, as you would opened still white wine. This slows oxidation; it does not restore the unopened state. Mark the opening date, follow specific producer guidance and do not treat the closure as a universal freshness guarantee or a reason to finish the bottle.

**Can I compare closures without tasting wine?**

Yes. Compare the producer's closure information, intended storage and opening requirements on paper. Note what is documented and what remains unknown. This is useful wine literacy without alcohol consumption. Even tasting unrelated cork- and screw-capped wines cannot isolate the closure's effect because the wines and their storage histories may differ.


---

# How to Read a Wine Label Without Guessing

> Read a wine label in three passes. First identify brand or producer, class or type, variety if stated, and origin. Next record vintage, alcohol, and volume. Finally find bottler, producer, or importer wording, country of origin where required, warning, sulfites, and optional claims or certifications. Rules vary by market, so use the relevant authority rather than a universal glossary. Treat vintage and place as information, not quality guarantees, and verify terms such as reserve, estate, organic, natural, or sustainable before inferring more than the label establishes.

Source: https://richmondwinestation.com/read-wine-label-without-guessing/  
Publisher: Bottle & Context  
Published: 2026-07-19  
Updated: 2026-08-26

## Read the bottle in three passes

A wine label can tell you who put a name on the bottle, what kind of wine it is, where its fruit came from under applicable rules, how much alcohol and liquid it contains, and who bottled or imported it. It can also show a chateau sketch that has never once completed a harvest.

Read in three passes:

1. **Identity:** brand or producer, class or type, grape variety, and origin.
2. **Numbers:** vintage, alcohol content, and net contents.
3. **Responsibility and claims:** bottler or importer, warnings, sulfites, production terms, certifications, awards, and marketing prose.

Rules differ by country and product category. This guide uses current US federal wine labels as a worked example, not a universal decoding key.

## Separate brand, producer, and responsible business

The largest name may be a brand, estate, producer, cuvée, or proprietary wine name. Turn the bottle around and find the name-and-address statement. Wording such as “bottled by,” “produced and bottled by,” “cellared by,” or “imported by” can carry specific regulatory meanings; do not compress them all into “the winery made everything.”

For US-market wine, the Alcohol and Tobacco Tax and Trade Bureau's [wine-labeling guide](https://www.ttb.gov/regulated-commodities/beverage-alcohol/wine/labeling) lists mandatory and optional information and links definitions. Imported bottles may also show a country of origin and US importer.

Record the exact wording when provenance matters. A family story on the back can provide context, but the responsible-business statement is the better starting point for tracing the product.

## Find the class, type, or variety

A label may identify “red wine,” “sparkling wine,” Chardonnay, a blend, or another regulated class or type. A grape name is not automatically the producer name, place, flavor guarantee, or proof that no other varieties are present. The percentage required for a varietal designation depends on the governing rules and origin.

When a bottle names several grapes, look for percentages but do not assume they must appear. If sweetness, carbonation, flavor additions, or production method matters to you, identify the exact type statement and check the producer's current technical information. Front-label minimalism often sends the useful nouns to the back.

Browse [label literacy](/label-literacy/) for country-specific terminology without treating similar words as identical legal claims.

## Treat origin as a defined claim

An appellation designates a geographic area where the fruit or other agricultural product was grown under applicable rules. In the United States, an American Viticultural Area is one type of appellation for grape wine. TTB explains that using an appellation can also indicate compliance with production requirements, and that an appellation becomes mandatory when labels make certain claims, including a varietal designation or vintage date.

That does not mean every place name has the same percentage rule, boundary logic, or quality promise. Read the named area exactly. A broad country, state, or county origin and a smaller recognized region communicate different scopes, not an automatic ladder from bad to good.

The [TTB appellation overview](https://www.ttb.gov/regulated-commodities/beverage-alcohol/wine/labeling-wine/wine-labeling-appellation-of-origin) covers US usage; imported appellations follow their home-country rules as recognized for labeling.

## Understand vintage without predicting quality

Vintage identifies the harvest year represented under the applicable rule. It is not necessarily the bottling year or release year. Weather can make vintage informative, but the year alone cannot tell you whether a bottle was well grown, made, stored, transported, or suited to your taste.

Some wines are intentionally non-vintage blends. That is not a confession. Blending across years may support a consistent house style or other production goal. If the bottle lacks a vintage, read the type and producer information before declaring the calendar missing in action.

## Read alcohol and volume literally

Find the alcohol statement and net contents. Alcohol content may appear on a different label panel from the brand information. In some US table-wine circumstances, class wording can stand in for a numerical percentage; TTB's [label anatomy tool](https://www.ttb.gov/regulated-commodities/beverage-alcohol/wine/anatomy-of-a-label) explains the conditions.

Alcohol percentage describes concentration, not quality, sweetness, body, or how much any individual should drink. Serving guidance and legal limits depend on location and person. This publication is for adults of legal drinking age. Do not drink before driving, operating equipment, swimming, supervising safety-critical activity, during pregnancy, or when alcohol conflicts with medication, health guidance, recovery, or personal choice.

## Put optional claims on probation

“Reserve,” “old vine,” “natural,” “handcrafted,” “estate,” “single vineyard,” “organic,” and sustainability marks do not share one global definition. Some are regulated in a market or context; others may be producer language. Look for the certifying body, standard, scope, vintage, and current documentation.

Awards identify a competition result under its entry and judging conditions. Scores identify a reviewer's assessment of a submitted or purchased sample. Neither proves your bottle's storage history or your preference.

Use our [two-wine comparison](/compare-two-wines-side-by-side/) to test a label-led expectation against the glass. Continue through [tasting practice](/tasting-practice/) with the bottle hidden if you want to reduce brand and price influence.

Finish by photographing both label panels and writing one neutral sentence: “2024 varietal wine from named region, bottled by stated business, listed alcohol, standard bottle volume.” Facts first. The peacock can enter afterward.

## Frequently asked questions

**Is the biggest name on a wine label the producer?**

Not necessarily. It may be a brand, estate, producer, cuvée, or proprietary wine name. Find the name-and-address statement and read exact wording such as produced, bottled, cellared, or imported by, because those phrases can have regulatory meanings. Use the relevant market's official label guidance and current producer information when provenance matters. A back-label family story does not replace the responsible-business statement.

**What does appellation mean on a wine label?**

An appellation identifies a geographic area where the grapes or other agricultural product were grown under applicable rules. In the United States, an American Viticultural Area is one kind of grape-wine appellation. Place claims can trigger origin and production requirements, but rules differ among countries and appellation levels. The name does not automatically guarantee quality or taste; read its exact scope and the governing authority.

**Does wine vintage mean the year it was bottled?**

No. Vintage identifies a harvest year under the rules applying to that label; bottling and release can happen later. The year can provide useful context about growing conditions and age, but cannot by itself prove quality, storage, readiness, or style. Non-vintage wine is not inherently inferior: blending across years can support a producer's intended profile. Check the producer's technical information for more detail.

**Does alcohol percentage tell me whether wine is sweet?**

No. Alcohol content states concentration, not sweetness, body, quality, or a safe personal amount. Fermentation choices, residual sugar, acidity, and other components affect perceived sweetness and balance. Read any lawful sweetness or style information and taste in context. Alcohol affects people differently; this guide is for adults of legal age, and nobody should drink before driving or when alcohol conflicts with health, medication, pregnancy, recovery, or personal choice.

**Are reserve and old-vine claims regulated?**

Their meaning depends on the country, region, and exact context. Some wine terms have legal definitions or production requirements in one market but not another. Look for the governing appellation rule, producer specification, certification, or documented vine age rather than assuming a global standard. The same caution applies to natural, handcrafted, estate, organic, and sustainable language. Ask what was certified, by whom, to which standard, and for which vintage.


---

# Wine pH vs Titratable Acidity: Read Both Numbers

> Wine pH and titratable acidity, or TA, are different measurements: one cannot replace the other. Read pH as an acidity-scale value and TA with its stated units and reporting basis. Match the technical sheet to the exact wine before comparing figures. This guide is for adults of legal drinking age; the document exercise requires no drinking.

Source: https://richmondwinestation.com/wine-ph-vs-titratable-acidity/  
Publisher: Bottle & Context  
Published: 2026-10-10  
Updated: 2026-10-10

## What is the difference between wine pH and TA?

Wine pH and titratable acidity, or TA, are different measurements: one cannot replace the other. Read pH as an acidity-scale value and TA with its stated units and reporting basis. Match the technical sheet to the exact wine before comparing figures. This guide is for adults of legal drinking age; the document exercise requires no drinking.

A producer's technical sheet can look reassuringly precise while still leaving a question unanswered. The useful skill is knowing which question belongs to which number. This is a desk-researched reading guide, not a wine review or a procedure for testing or altering wine.

## What does the pH number mean?

The [USGS explanation of pH](https://www.usgs.gov/water-science-school/science/ph-and-water) describes a logarithmic scale related to hydrogen ions in an aqueous solution. Lower values indicate greater acidity. A difference of one whole pH unit represents a tenfold change, not a change of one percent.

Read a value such as pH 3.4 as a scale value, not as 3.4 grams of acid per litre. Keep the field name attached whenever you copy the number into your notes. Do not add a percent sign.

## What does titratable acidity measure?

TA is an acidity result from titration, affected by acid amounts and the hydrogen ions they can contribute. The Australian Wine Research Institute explains that [TA includes contributions from several acids](https://www.awri.com.au/wp-content/uploads/2011/07/Technical_Review_Issue_221_Wilkes.pdf), not just tartaric acid. It is usually reported in grams per litre expressed as tartaric acid, a reporting convention that does not mean all the measured acidity comes from that one acid.

Copy the reporting basis. Ask the producer what an unexplained "acidity" heading means.

## Can you calculate one from the other?

Do not turn a pH result into a TA value with a unit conversion. AWRI's [analysis of Australian wine composition](https://www.awri.com.au/wp-content/uploads/2024/05/s2329-Australian-trends-Titratable-acidity-pH.pdf) describes the relationship between TA and pH as indirect. They are not two units for the same result.

## How do you compare two different TA units?

Here is an original document exercise using invented figures, not measurements from real bottles. Both sample sheets explicitly identify TA expressed as tartaric acid:

| Field | Sample sheet A | Sample sheet B |
|---|---|---|
| Wine identity | Fictional white, lot A | Fictional white, lot B |
| pH | 3.25 | 3.45 |
| TA as printed | 6.4g/L | 0.64g/100mL |
| TA on the same volume basis | 6.4g/L | 6.4g/L |

There are ten 100mL portions in one litre. Multiply 0.64 by 10 to obtain 6.4g/L. The TA quantities match on that volume basis; the pH values remain different. You have normalized a unit, not established that the wines taste alike or that either is better.

Now change only sheet B's TA to 0.70g/100mL. Its equivalent becomes 7.0g/L. The difference from sheet A is 0.6g/L: 7.0 minus 6.4. Keep the original value beside the conversion so somebody else can follow the arithmetic.

Do not apply this shortcut to an unexplained percentage. First establish whether the document means grams per 100mL or a different basis. Also confirm that both entries describe the same measurement and acid-reporting convention. Arithmetic cannot repair unlike inputs.

## Which details belong in your record?

Before comparing numbers, use our [wine-label guide](/read-wine-label-without-guessing/) to establish identity. Then make a short record with these fields:

- Producer, exact wine name, vintage or non-vintage designation, and any stated lot.
- Technical-sheet URL or filename and the date you retrieved it.
- Each printed field name, value, unit and reporting basis.
- Any conversion, showing both the original and converted figures.
- Unanswered questions, with the producer's response kept alongside them.

This is our editorial document checklist. It is not a certification standard. A retailer's undated description may help locate a producer's sheet, but it should not silently replace a document for the actual bottle under consideration.

Imagine finding two sheets with the same wine name but different vintages. Do not average their values. Identify which vintage you mean, retain that document, and ask about any remaining discrepancy. If neither sheet identifies the bottle precisely enough, record the uncertainty instead of selecting whichever figure looks more convenient.

Keep any optional [tasting comparison](/compare-two-wines-side-by-side/) separate from the document record. One records published information; the other records personal observations. Neither should be rewritten to make it agree with the other.

## Does an acidity figure establish suitability to drink?

Do not treat this worksheet as a safety assessment or a health recommendation. No tasting is needed to complete it.

[NIAAA advises avoiding alcohol](https://www.niaaa.nih.gov/alcohols-effects-health/alcohol-drinking-patterns) before driving or activities requiring skill and alertness, during pregnancy or possible pregnancy, with interacting medicines or certain medical conditions, and during recovery from alcohol use disorder or when unable to control drinking. Follow individual medical advice. Choosing not to drink requires no explanation.

The finished record should let you say exactly what a document supplies, what you converted, and what remains unknown. That is useful progress even when no bottle is opened.

## Sources

- [USGS: pH and water](https://www.usgs.gov/water-science-school/science/ph-and-water)
- [AWRI: Wine acids, not just tartaric](https://www.awri.com.au/wp-content/uploads/2011/07/Technical_Review_Issue_221_Wilkes.pdf)
- [AWRI: Titratable acidity and pH](https://www.awri.com.au/wp-content/uploads/2024/05/s2329-Australian-trends-Titratable-acidity-pH.pdf)
- [NIAAA: Alcohol drinking patterns](https://www.niaaa.nih.gov/alcohols-effects-health/alcohol-drinking-patterns)

## Frequently asked questions

**Is pH 3.4 the same as 3.4 percent acid?**

No. pH is a logarithmic scale value, not a percentage or a mass of acid. Keep the pH label attached to the number when recording it. If another field is expressed as a percentage, read its definition separately rather than treating the two figures as interchangeable.

**How do I convert 0.64g/100mL to grams per litre?**

Multiply by ten, because one litre contains ten portions of 100mL. The result is 6.4g/L. Keep the original figure beside your calculation and preserve the stated measurement and reporting basis. This changes the volume unit; it does not supply information missing from the original document.

**Can I fill in a missing TA result from the pH?**

No. AWRI describes their relationship as indirect; pH and TA are not interchangeable results. Leave the missing entry marked not supplied and ask the producer for the appropriate information. Do not borrow an acidity figure from another vintage simply because the wine name looks the same.


---