Why does my chocolate taste like that?

Two things account for a startling proportion of complaints about chocolate and neither is a fault in the chocolate.

IT IS TOO COLD. Cocoa butter is solid below about 30°C and its aroma reaches you as it melts. A bar straight from a fridge releases very little of anything, and it tastes flat, hard and faintly of nothing. Ten minutes at room temperature is the difference between a bar and the same bar.

YOU ATE IT TOO FAST. Chocolate's flavour arrives in sequence — sweetness and acidity first, roast and fruit as the fat melts, bitterness and astringency last. Chewing and swallowing skips most of it. Let a piece melt on the tongue and the same bar has three times the flavour, which is why every tasting guide in this catalogue starts with that instruction.

If a chocolate seems dull, try both before concluding anything. Then work down this page.

THE MOST DIAGNOSTIC SENSATION THERE IS, because cocoa butter's melting behaviour is unusual and hard to imitate.

Cocoa butter is solid and brittle at room temperature and fully liquid a little below body temperature, and it makes that transition across a narrow range. Anything that melts slowly, coats the mouth, or leaves a film has a different fat in it.

THE USUAL CAUSE IS A VEGETABLE FAT REPLACING SOME OR ALL OF THE COCOA BUTTER. In the EU up to 5% of specified other vegetable fats is permitted in something still called chocolate, with mandatory declaration; beyond that — or in a coating — the product is compound and in most markets may not be called chocolate at all. Check the ingredient list for palm, shea, illipe or 'vegetable fats'; check the front of the pack for a qualified descriptor.

A SECOND CAUSE IS FAT BLOOM. Cocoa butter that has melted and recrystallised badly migrates to the surface in a form that melts higher and less cleanly. The bar will usually look dull or streaked as well.

Neither makes a product bad at what it is. A compound coating is engineered to survive a warm room without tempering, which is a real job. It is simply not chocolate, and the mouth notices before the label does.

THREE QUITE DIFFERENT CAUSES and they are distinguishable.

SHARP, FRUITY, VINEGAR-LIKE ACIDITY is a fermentation and drying signature. Cacao fermentation produces acetic and lactic acid, and drying is where most of the acetic acid is meant to leave. Beans dried too fast — or fermented too long — retain it. This is common in origins and lots where post-harvest is under-resourced, and it is a processing outcome rather than spoilage.

A CHEESY, SLIGHTLY VOMIT-LIKE TANG in milk chocolate is butyric acid, released from milk fat by controlled lipolysis. It is deliberate, it is characteristic of some American milk chocolate, and it is what a great many people mean when they say chocolate from another country tastes wrong. It has its own glossary entry.

BRIGHT, CLEAN FRUIT ACIDITY that reads as red fruit or citrus is not a fault at all. It is what a well-fermented fine-flavour bean tastes like, and it is why Madagascan chocolate divides opinion. The catalogue's comparison between acidity and sourness is the page for telling the two apart.

PARTICLE SIZE FIRST. Chocolate is a suspension of sugar and cocoa solids in fat, refined until the particles fall below the size the tongue can detect — around twenty to thirty micrometres. Under-refined chocolate is detectably gritty, and it is a manufacturing shortfall.

SUGAR BLOOM SECOND, and it is the commoner cause in a bar that was once fine. Moisture — condensation from a fridge, a damp cupboard — dissolves surface sugar; the water evaporates and leaves recrystallised sugar behind as a rough, gritty film. The bar will look dusty rather than greasy. It is harmless and it does not go away.

AND IN A DRINK, undissolved cocoa. Cocoa never dissolves; it disperses, and badly wetted cocoa is grit. That has a page of its own.

Also worth knowing: a chocolate high in milk powder or with a lot of added fibre in a reduced-sugar formulation can read as chalky by composition rather than by fault.

SEPARATE BITTERNESS FROM ASTRINGENCY, because they feel similar and have different causes.

BITTERNESS is a taste, from theobromine, caffeine and polyphenols. It rises with cocoa content, so an 85% bar is meant to be bitter and a complaint about it is a preference rather than a fault.

ASTRINGENCY is a tactile drying, from polyphenols binding salivary proteins. High astringency in a bar usually means UNDER-FERMENTED beans: fermentation is where a large share of those polyphenols is degraded, and skipping it leaves them in.

SO A BAR THAT IS DRYING AS WELL AS BITTER is telling you something about its post-harvest, and a bar that is merely bitter is telling you its percentage.

The cheapest fix for either is a pinch of salt if you are cooking with it, or a lower percentage if you are eating it. Neither is a repair — they are compensations, and the flavour perception guide explains why they work.

SMOKY IS USUALLY DRYING, NOT ROASTING. Beans dried over fire — because the harvest coincided with rain, because no drying infrastructure exists — pick up phenolic smoke taint that survives everything downstream. It is characteristic of particular origins and particular seasons and it is a post-harvest outcome, not a roast profile. Papua New Guinean cocoa is the best-known example and the catalogue covers it on that page.

BURNT, ACRID BITTERNESS is over-roasting, and it is a manufacturing decision. Dark-roasting develops pyrazines and destroys delicate volatiles; taken too far it produces the flat, scorched character of cheap cocoa powder.

HAMMY, SMOKED-MEAT NOTES sit between the two and are generally read as a defect in fine chocolate and as a signature in some traditional lots. Whether it is a fault depends entirely on what the bar was trying to be, which is the honest answer more often than people expect.

A very common complaint and almost always a formulation fact rather than a fault.

Sweetness suppresses bitterness perception and is itself suppressed by it. A bar at 30% cocoa is roughly half sugar, and there is not enough cocoa in it to push back — so the sweetness is what is left. That is what mass-market milk chocolate is designed to be, and it is designed that way because it sells.

WHAT MAKES IT WORSE: low cocoa content, a high proportion of milk solids, a compound coating supplying no cocoa bitterness at all, and a product where a flavouring rather than cocoa is doing the work. That last case has a page of its own, and the giveaway is an intense front and a short finish with no bitterness behind it.

WHAT FIXES IT: a higher percentage, or a dark milk chocolate in the 45 to 55% range, which is the answer most people are actually looking for and almost nobody is offered.

COCOA BUTTER ABSORBS SMELLS. It is a fat, it is porous to volatiles, and it sits in a cupboard next to whatever else is there. Chocolate stored near coffee, spices, cheese or a strong-smelling fridge picks them up, and the effect is not subtle.

STALENESS is oxidation, and it shows up fastest in bars with nuts in them: nut oils are highly unsaturated and go rancid long before the chocolate does. A rancid nut tastes sharply of paint and ruins whatever it is in.

MUSTY OR MOULDY notes can be a bean-level defect — poorly dried or poorly stored beans — and are one of the few things on this page that is unambiguously a fault.

None of these is a food-safety matter at ordinary storage. Old chocolate is generally safe and unpleasant, which is a different thing, and the storage guides cover the distinction properly.

NOT A FLAVOUR PROBLEM, and it is here because it is the commonest thing people think is one.

A grey-white film is BLOOM. Fat bloom follows heat; sugar bloom follows damp. Both are cosmetic, both mean the chocolate has been stored badly, and neither means it has spoiled. Fat bloom feels soft and greasy and follows the shape of the bar; sugar bloom feels rough and crystalline.

NO SNAP AND A SOFT TEXTURE means the chocolate is out of temper — melted and re-set without the right crystal form. Common in home-made confections and in bars that have been warm.

All of it is edible, and the catalogue has three pages on why, because the belief that white marks mean spoiled chocolate is the single most persistent misconception in this subject.