How do coffee tannins compare to tea tannins?

Tea (especially black tea) is typically much richer in classical tannins than coffee. Black tea gets its characteristic drying astringency primarily from theaflavins and thearubigins — condensed polyphenols formed during tea oxidation. Green tea contains catechins (especially EGCG), which are potent astringents. Coffee's main polyphenols are chlorogenic acids, with smaller amounts of condensed tannins. Most people who describe coffee as 'tannic' are responding to chlorogenic acids and over-extraction compounds rather than the classical tannin compounds dominant in tea.

What causes astringency in coffee?

Astringency is the dry, puckering sensation caused by polyphenols binding to salivary proteins (mucins and proline-rich proteins), precipitating them and reducing lubrication in the mouth. In coffee, the primary astringency contributors are chlorogenic acids (dominant in lighter roasts), chlorogenic acid degradation products like quinolactones and vinyl catechols (more prominent in darker roasts), and melanoidins — the brown-coloured polymers formed during Maillard reactions. True tannins contribute, but they are not the primary source.

Does over-extraction make coffee more tannic or astringent?

Yes. Polyphenolic compounds including chlorogenic acids, degradation products, and melanoidin precursors continue to extract throughout brewing. Longer extraction time, finer grind size, and higher temperature all increase polyphenol extraction. An over-extracted coffee pulls in more of these astringent compounds, producing a dry, harsh mouthfeel. This is why espresso brewed at the correct time (25–30 seconds) can have significantly less perceived astringency than one pulled at 45 seconds.

Does roast level affect tannin and astringency content?

Roast level changes which astringent compounds are present rather than simply increasing or decreasing total astringency. Light roasts have higher chlorogenic acid content (more raw polyphenolic astringency). Dark roasts have lower CGA content but higher levels of CGA degradation products — quinolactones and phenyl indanes — which are more bitter and astringent than CGAs. Medium roasts sit at a transition point where degradation is partial. Many coffee drinkers who describe light roasts as 'sharp' or dark roasts as 'harsh' are responding to different polyphenolic profiles, not different amounts of the same compounds.

Brewing Science

Does Coffee Have Tannins? Astringency Explained

By Coffee Studies Editorial·Published July 18, 2026·5 min read

Quick answer

Coffee does contain tannins, but in much smaller quantities than tea and of a different chemical profile. The compounds most responsible for astringency in coffee are not classical tannins but chlorogenic acids and their degradation products, along with melanoidins produced during roasting. Classical tannins — the polyphenols that give tea and red wine their characteristic drying, mouth-puckering sensation — are present in coffee but at lower concentrations. Over-extraction amplifies astringency by pulling more of these polyphenolic compounds into the cup.

An overhead close-up of ground coffee in a filter basket, a fine texture visible, soft side lighting on the grounds, minimal composition

"Does coffee have tannins?" is a question that generates confident answers in both directions, often from people conflating several different things. The short answer is yes — but understanding what that actually means requires separating tannins specifically from the broader category of coffee polyphenols, and understanding that the astringency most people associate with tea tannins has a different primary source in coffee.

Chlorogenic acids: 6–10% of green coffee dry weight

the dominant polyphenols in coffee are chlorogenic acids — which share some astringent properties with tannins through protein binding, but are chemically distinct from the condensed and hydrolyzable tannins responsible for tea's characteristic astringency^[2]

Astringency = protein precipitation in saliva

tannins, chlorogenic acids, and other polyphenols create astringency through the same mechanism — they bind salivary proteins, causing them to precipitate and reducing the lubricating film in the mouth; the drying, puckering sensation is the result^[1]

Over-extraction amplifies polyphenol content

the astringent polyphenolic compounds in coffee continue extracting throughout the brew — longer extraction, finer grind, and higher temperature all pull more of these compounds into the cup, increasing perceived astringency^[4]

What tannins actually are

Tannins are a broad class of polyphenolic compounds defined by their ability to bind and precipitate proteins. The name comes from their historical use in leather tanning — binding to animal hide proteins to preserve and harden them.

There are two main structural types relevant to beverages:

Condensed tannins (proanthocyanidins): Polymers of flavan-3-ol units (catechins and epicatechins). These are the dominant tannins in red wine and dark tea. They bind salivary proteins strongly and create a characteristic drying, puckering astringency. Black tea's astringent character comes primarily from theaflavins and thearubigins — condensed tannin polymers formed during tea oxidation.

Hydrolyzable tannins: Gallic acid and ellagic acid esters of glucose. Found in oak-aged wines and some fruits. Less dominant in coffee.

Both types create astringency through the same mechanism: binding to salivary proline-rich proteins and mucins, causing them to aggregate and precipitate. The lubrication of the mouth surface decreases, producing the drying sensation.

What polyphenols coffee actually contains

The polyphenolic profile of coffee is dominated by a compound class that is related to tannins but distinct from them^[2]:

Chlorogenic acids (CGAs): Esters of caffeic acid and quinic acid. These are the largest polyphenol fraction in green coffee (6–10% of dry weight). They have some protein-binding activity and astringency — they belong to the broader hydroxycinnamic acid family of phenolics — but they are not classified as tannins. The distinction matters because their astringency profile, the degree of protein binding, and the compounds they degrade into during roasting are different from classical tannins.

Condensed tannins: Present in coffee in small amounts, particularly in the outer layers of the green bean. Proanthocyanidins have been detected in both green and roasted coffee, but at lower concentrations than the CGA fraction^[1].

Melanoidins: High-molecular-weight brown polymers formed during Maillard reactions in roasting. They have significant protein-binding capacity and contribute to both the body (texture) and astringency of roasted coffee. Melanoidins are coffee-specific compounds not present in tea or wine.

CGA degradation products: Roasting converts CGAs into quinolactones, vinyl catechols, phenyl indanes, and related compounds. Some of these are more astringent than the parent CGAs; others are primarily bitter. They are formed progressively with increasing roast temperature.

Why coffee tastes different from tea

Most people who drink both tea and coffee notice a qualitative difference in astringency — tea often has a more pronounced drying, cheek-coating astringency, while coffee's astringency is harder to separate from bitterness and feels less "clean."

The reason is the different polyphenol profiles^[3]:

Black tea's astringency: Driven primarily by theaflavins and thearubigins — condensed tannin polymers with very strong salivary protein affinity. These bind quickly and dramatically, producing the characteristic tea astringency in a short brew time. The sensation is distinct and separable from bitterness.

Coffee's astringency: Driven by a mixture of chlorogenic acids (partial protein binding, more acid-bright than tannic), melanoidins (strong protein binding but high molecular weight — contributes to body as much as astringency), and CGA degradation products (varying degrees of protein binding and bitterness). The mix is more complex and the sensory impression harder to separate into clean astringency.

Figure

Polyphenol types in coffee by roast level (relative concentration)

Values in relative concentration (light roast = 100)

Chlorogenic acids (light roast)

100maximum CGA content in light roast — 6–10% of dry bean weight; primary source of light roast brightness and some astringency

Chlorogenic acids (medium roast)

55medium roast degrades 40–60% of green bean CGAs through heat-driven hydrolysis and Maillard side-reactions

Chlorogenic acids (dark roast)

10nearly complete CGA degradation in dark roast; residual CGAs account for only a fraction of original content

Melanoidins (light roast)

30melanoidins form during roasting — lower concentration in light roast; contribute to body and mild astringency

Melanoidins (dark roast)

100dark roast has maximum melanoidin content from extensive Maillard reactions; these high-MW polymers contribute heavily to dark roast body and astringency

CGA degradation products (dark roast)

100quinolactones, phenyl indanes, vinyl catechols — products of CGA breakdown at high temperature; primarily bitter but some astringent character

Concentrations are illustrative relative values — actual quantities vary substantially by origin, processing, and exact roasting temperature profile. The key relationships (CGA declining, melanoidins increasing with roast) are well-established.^[1]

How brewing method affects polyphenol extraction

The polyphenolic compounds in coffee extract progressively during brewing. Variables that affect extraction:

Time: Longer contact between water and grounds extracts more polyphenols. A French press steeped for 8 minutes pulls significantly more astringent compounds than one steeped for 4.

Temperature: Higher water temperature increases extraction rate for all compounds, including polyphenols. Cold brew (20°C over 12–24 hours) extracts polyphenols more slowly and selectively — some of the more astringent CGA degradation products extract less efficiently at cold temperatures, which partly explains cold brew's reported smoother character^[4].

Grind size: Finer grind creates more surface area, accelerating extraction including polyphenol extraction. An overly fine grind at the same brew time over-extracts both desirable and astringency-contributing compounds.

Filter type: Paper filters trap oil droplets and fine particles, some of which carry polyphenols (including melanoidin precursors). Metal filters allow oils and fine particles through, producing heavier body and potentially higher melanoidin content in the cup.

Reducing astringency in practice

Understanding the sources of coffee astringency points to practical adjustments:

Coarsen the grind if coffee tastes dry or puckery — over-extraction is a common cause
Shorten extraction time for the same reason
Use paper filters to trap some of the melanoidin precursors and oils that contribute to astringency
Choose lighter roast for lower CGA degradation products (but higher raw CGA acidity) or darker roast for lower total CGA (but higher melanoidins and degradation products)
Lower water temperature by a few degrees — hotter water extracts astringent compounds more aggressively

The honest summary

Coffee does contain tannins — primarily condensed proanthocyanidins — but in lower concentrations than tea, and these are not the primary source of coffee's astringency. The dominant polyphenols in coffee are chlorogenic acids (6–10% of green bean dry weight), which share protein-binding astringency with tannins but are chemically distinct. Roasting progressively converts CGAs into degradation products (quinolactones, phenyl indanes) and simultaneously builds up melanoidins — both of which contribute to the complex bitterness-astringency profile of darker roasts. Over- extraction amplifies astringency regardless of roast level by pulling more polyphenolic compounds into the cup. Coffee is genuinely less tannic than strong black tea but has its own distinct astringency profile driven by its specific polyphenolic composition.

Frequently asked questions

Does coffee have tannins?: Yes, coffee contains tannins, but in lower concentrations than tea and of a partially different chemical character. Green and roasted coffee contain condensed tannins (proanthocyanidins) and some hydrolyzable tannins, but the dominant polyphenols in coffee are chlorogenic acids — which share some tannin-like properties (protein binding, astringency) but are chemically distinct. Coffee's astringency is better attributed to chlorogenic acids, their degradation products, and melanoidins than to classical tannins.
How do coffee tannins compare to tea tannins?: Tea (especially black tea) is typically much richer in classical tannins than coffee. Black tea gets its characteristic drying astringency primarily from theaflavins and thearubigins — condensed polyphenols formed during tea oxidation. Green tea contains catechins (especially EGCG), which are potent astringents. Coffee's main polyphenols are chlorogenic acids, with smaller amounts of condensed tannins. Most people who describe coffee as 'tannic' are responding to chlorogenic acids and over-extraction compounds rather than the classical tannin compounds dominant in tea.
What causes astringency in coffee?: Astringency is the dry, puckering sensation caused by polyphenols binding to salivary proteins (mucins and proline-rich proteins), precipitating them and reducing lubrication in the mouth. In coffee, the primary astringency contributors are chlorogenic acids (dominant in lighter roasts), chlorogenic acid degradation products like quinolactones and vinyl catechols (more prominent in darker roasts), and melanoidins — the brown-coloured polymers formed during Maillard reactions. True tannins contribute, but they are not the primary source.
Does over-extraction make coffee more tannic or astringent?: Yes. Polyphenolic compounds including chlorogenic acids, degradation products, and melanoidin precursors continue to extract throughout brewing. Longer extraction time, finer grind size, and higher temperature all increase polyphenol extraction. An over-extracted coffee pulls in more of these astringent compounds, producing a dry, harsh mouthfeel. This is why espresso brewed at the correct time (25–30 seconds) can have significantly less perceived astringency than one pulled at 45 seconds.
Does roast level affect tannin and astringency content?: Roast level changes which astringent compounds are present rather than simply increasing or decreasing total astringency. Light roasts have higher chlorogenic acid content (more raw polyphenolic astringency). Dark roasts have lower CGA content but higher levels of CGA degradation products — quinolactones and phenyl indanes — which are more bitter and astringent than CGAs. Medium roasts sit at a transition point where degradation is partial. Many coffee drinkers who describe light roasts as 'sharp' or dark roasts as 'harsh' are responding to different polyphenolic profiles, not different amounts of the same compounds.

References

Every factual claim in this article is drawn from the sources below. See the source library for how we grade evidence.

[1]Impact of roasting on phenolic and volatile compounds in coffeePMC / NIH · 2022 · Review · Tier 2 · Moderate
[2]Coffee chlorogenic acids: a reviewPMC / NIH · 2022 · Review · Tier 2 · Moderate
[3]Coffee volatile compounds and roast markersPMC / NIH · 2016 · Review · Tier 2 · Moderate
[4]Brewing FundamentalsCoffee Science Foundation · Reference work · Tier 2 · Moderate