Tea can be a precise, expressive flavour in baking, when you understand how its chemistry behaves in fat, water, starch and protein systems.
What tea brings to baked goods
Tea is rich in polyphenols (including catechins and theaflavins), caffeine, amino acids and aromatic compounds, all of which affect flavour, colour and texture. Catechins and related tannins contribute bitterness and astringency, while amino acids and sugars participate in Maillard reactions that deepen colour and roasted notes during heating. Baking or roasting tea leaves themselves shifts their chemistry: catechins degrade, bitterness and astringency reduce, while sweet, thick mouthfeel and roasted aromatics increase. These changes explain why some baked tea flavours taste mellow and toasty rather than sharply tannic, especially with oolong and baked green teas.
How tea interacts with batter and dough
Tea polyphenols can bind to proteins, including gluten and interfere with the formation of a strong elastic network. Experimental cake batters with high levels of tea have shown reduced rise and a thinner, “ropey” texture, consistent with polyphenols cross-linking proteins and preventing them forming a cohesive gas-trapping web. This inhibitory effect appears stronger at higher tea levels (around 12 g tea per ~400 g batter) and is mitigated by cooler resting, suggesting temperature-dependent binding kinetics. Tea polyphenols also interact with starch: in bread digestion models, green tea extracts reduce starch digestibility and increase resistant starch, implying they form complexes with starch granules and enzymes. In practical baking, these interactions can subtly change crumb firmness and staling, especially when tea is added directly rather than via a dilute infusion.
Extracting flavour: water, fat and solids
Tea’s characteristic molecules distribute between water, fat and insoluble leaf material, so the method you choose strongly shapes flavour and texture.
- Using brewed tea as liquid
Steep tea in water or milk, then use this as all or part of the recipe liquid. Hot infusions extract a broad spectrum of water-soluble compounds (tannins, amino acids, many aromatics), giving a clear tea flavour but, if over-steeped, can develop bitterness and astringency. Cold infusions in milk or syrup skew towards less polar, more fat-soluble aromatics and can produce a softer, more perfumed profile with less harshness. - Infusing fat (butter, cream)
Tea leaves can be gently heated in melted butter or warm cream, then strained, transferring fat-soluble aromatics into the fat phase. This method emphasises floral, citrus and toasted notes while reducing extraction of harsher tannins, because many of those remain in the discarded leaves. Using tea-infused butter in shortbread or sponge delivers integrated flavour with no visible particles and minimal change to water content. - Grinding and adding leaves
Finely ground tea (using a spice or coffee grinder) can be mixed with dry ingredients to add both flavour and speckled appearance. This works well in low-hydration, low-rise items such as shortbread and biscuits where slight texture from particles is acceptable or even desirable. In light sponges, coarser particles can taste gritty, and high solid tea loadings accentuate the protein-binding effects that reduce rise.
These methods can be combined – for example, a strong tea infusion in the batter plus a lightly ground tea for visual cues – but each extra extraction step increases the risk of over-extracting tannins.
Controlling bitterness, astringency and baking reactions
Balancing tea’s bitterness and astringency against sweetness and fat is central to getting a pleasant flavour in cakes and biscuits.
- Managing tannins and catechins
Longer or hotter steeping extracts more catechins and tannins, boosting bitterness and mouth-drying astringency. Baking itself further alters catechin composition: monomeric catechins (strongly astringent and bitter) degrade and form dimers and Maillard-derived products that can taste more astringent but less sharply bitter, with added roasted notes. Using baked or roasted teas (like hojicha or roasted oolong) starts you from a less astringent, sweeter base, which is often easier to balance in sweet bakes than very green, unbaked teas. - Role of sugar and fat
Sugar suppresses perceived bitterness by competing at taste receptors and by increasing viscosity, which slows diffusion of bitter compounds to the tongue. Fats coat the palate and can physically solubilise hydrophobic aromatics, rounding the edges of tannin perception and carrying volatile tea aromas to the nose. Tea-infused fats thus not only deliver aroma but also modulate how tannins are sensed, often producing a smoother profile than water-only infusion at the same leaf dose. - Maillard and caramel notes
In batters and doughs, amino acids originating from tea contribute to Maillard reactions with reducing sugars, especially near the surface where temperatures are higher and moisture is lower. Studies on baked teas show increased pyrroles, furans and other Maillard volatiles, associated with roast, caramel and nutty aromas. When you bake with tea, some of these same classes of compounds are produced in situ, helping explain why tea-flavoured biscuits often have an appealingly toasty edge even at modest oven temperatures.
Practical implications for recipe design
Understanding the chemistry allows you to design recipes that showcase tea clearly without compromising structure.
- Choosing the tea
Green teas (especially matcha) bring grassy, marine and umami notes plus vivid colour; matcha powder is commonly used directly in batters and icings because it is already finely milled. Black teas contribute malt, citrus, spice and tannin; Earl Grey’s bergamot pairs particularly well with butter and sugar in biscuits and cakes. Roasted teas such as hojicha and certain oolongs yield gentle, nutty, almost coffee-like profiles with less astringency, suiting sponges and roll cakes. - Deciding how to add flavour
For delicate genoise or chiffon-style sponges, replacing part of the liquid with a strong but not over-steeped infusion and/or infusing the butter minimises disruption to gluten and starch behaviour. For dense biscuits and shortbread, finely ground leaves mixed into the flour provide robust flavour and visual flecks, and added tannins matter less because structure relies more on fat and starch than on a highly expanded gluten network. Buttercreams and glazes are excellent carriers for tea, as their high fat and sugar content buffer bitterness; infusing cream or butter, or using concentrated brewed tea in icing sugar, gives a controlled, layered flavour. - Managing structural side effects
If direct tea addition reduces rise or height, you can respond by slightly increasing chemical leavening, reducing tea solids, using an infused fat instead of dry leaf, or chilling the batter after mixing to slow polyphenol–protein binding. Where polyphenols might toughen crumb or darken colour more than desired, switching to a less oxidised or roasted tea, shortening infusion time, or shifting part of the flavour into a soak syrup or icing can re-balance the effect. As an illustration, some bakers infuse tea into simple syrup and brush this onto a neutral sponge, giving clear tea aroma without loading the batter itself with tannins and particles.
By treating tea not just as a flavouring but as a complex source of polyphenols, aromatics and reactive molecules, you can design bakes that highlight its character while keeping crumb, rise and mouthfeel under control.