The short answer: crystals look like fine, glittering, needle-like specks and smell of strong vanilla. Mould looks fuzzy, cottony or patchy, and usually smells musty. Crystals are a good sign. Mould means the bean should be thrown away.
What are vanilla crystals?
Vanilla crystals are natural vanillin, the main flavour compound in vanilla, that has come to the surface of the bean and crystallised. You'll sometimes hear them called frost, and beans with a heavy coating are sold as crystallized or frosted vanilla. They're a sign of a rich, well-cured bean.
How to tell them apart
| Vanillin crystals | Mould | |
|---|---|---|
| Looks like | Tiny, sparkly needles or a frosty sheen | Fuzzy, hairy or cotton-like patches |
| Colour | White or clear, catching the light | White, grey, green or blue |
| Where | Spread along the bean, often near the split | Often in patches, sometimes spreading from one spot |
| Smell | Strong, sweet vanilla | Musty, damp or sour |
| Texture | Crunchy or gritty if rubbed | Soft, and may smear |
A quick test
Look closely in good light, ideally with a magnifying glass or your phone camera zoomed in. Crystals glint like sugar or frost. Mould has a soft, furry texture. Then smell the bean: if it smells musty rather than sweet, it's mould.
What to do with mouldy beans
Throw them away, along with any beans that were touching them. Don't try to wipe or wash the mould off. Then check how you're storing the rest. Mould usually means too much humidity, so keep beans in an airtight container at room temperature, not in the fridge.
Still not sure?
Email a clear photo to info@pinisiandco.com and we'll take a look.