No products in the cart.
- SommWine's Ultimate Guide to WSET Level 1 is only $25
Shedding Light on Lightstrike: The Wine World’s Most Pervasive Flaw
How to Spot Lightstrike in Wines
Lightstrike is a frequently encountered wine flaw; one that often goes unnoticed. Therefore, this article covers the causes of lightstrike and crucially how to avoid getting this wine fault. Additionally, we’ll introduce a simple at-home test to learn what lightstrike tastes like so you can detect it too. Finally, we’ll explore the types of wines most susceptible to lightstrike and offer tips for selecting wines that are free from it. By the end of this post, we’ll completely safeguard your wine-drinking experience.
Table of Contents
Lightstrike in a nutshell
Smells like:
- in the early formation of lightstrike development, primary fruit aromas are missing.
- then the wine develops stinky aromas of dishwater, cooked cabbage, wet wool, onion, egg, damp cardboard or sewage
Looks like:
- most wines have no colour change at all – again making this common fault difficult to spot
- but colour may be dull
- or worse, wines may turn yellow or brown tinged
Tastes like:
- primary fruit flavours are missing. This makes it really difficult to spot
- then it develops awful flavours just like the aromas on the nose: dishwater, cooked cabbage, wet wool, onion, egg, damp cardboard or sewage – yuck!
How wines get lightstrike:
- lightstrike occurs simply by exposure to UV light
- wines are tainted in the bottling line, on your countertop or on supermarket shelves – anywhere there is UV light
The types of wine that are most susceptible:
- sparkling wines, white wines and pale rosé wines are especially susceptible to UV light
- wines that are in clear glass bottles have almost no protection from lightstrike
How to prevent lightstrike:
- store your wines in a cool dark place (like a basement cellar).
- use LED lights instead of UV lights or sunlight to see your stored wines
Lightstrike occurs when wines are exposed to too much UV light and/or blue light. When this happens, the wine produces volatile sulphur compounds which are smelly smells.
It’s like this…
Light reacts with riboflavin in the wine and photo-oxidizes methionine (a sulphur-containing amino acid also present in wine). When this happens, the reaction forms undesirable sulphur compounds such as dimethyl disulfide (or DMDS for short).
Moreover, a secondary reaction can also see light react with tartaric acid in the wine to form glyoxylic acid and hydrogen peroxide. This response contributes to the accumulation of yellow and brown pigments and changes the wines’ colour. In both cases, the effect is irreversible.
Is lightstrike harmful to drink? Luckily, the answer is no.
At low levels of detention, lightstruck wines just don’t offer much excitement – leaving you without a lasting impression or reason to buy the wine again. At higher levels, cooked cabbage, onion, smelly cheese, damp cardboard or raw sewage will jump out of your glass. The wine will totally stink and ruin your experience completely.
At low levels, lightstrike does the same thing as most other wine faults. It cancels out the fruitiness.
So that can be tricky to detect because you have to know what the wine is supposed to taste like before you know the fruit flavours are missing.
But it’s even trickier than this!
When the wine IS faulted, you will still be able to smell and taste the winemaking aromas and flavours.
Let’s take Champagne as an example. Toast, brioche, or freshly baked bread aromas come from the winemaking process. If your Champagne has lightstrike, you’ll still smell and taste those yummy notes.
However, lemon juice, apple and quince fruit will be missing – leaving you with a dissatisfied feeling overall.
Hence, you really must train yourself to ask, “Is it possible this wine has lightstrike?” Then ask yourself, “Can I smell and taste the fruit aromas?”
Along this thread, if you want to know which fruit aromas you are supposed to smell, do a quick search for tasting notes of the wine in an app like Vivino, Delectable and Cellar Tracker.
we’ll be right back after this ad from our sponsors.. more about lightstrike below!
Are you a WSET wine student?
Check out our mobile-friendly guides designed specifically for your WSET wine course
- Save time with our guides!
- flashcards + 100’s of multiple choice and matching questions
- and tips from a certified WSET-educator
Challenge yourself with these flashcards and quizzes. These guides will make your exam seem easy!
and backed by our 15-day 100% money back guarantee
Which wines are most affected by lightstrike?
Red wines have a secret weapon against lightstrike: tannin! It’s like their superhero power, shielding them from the harmful effects of light exposure.
Meanwhile, white wines lack this protective shield. Same story with delicate rosés—they’re like the fairytale princesses of the wine world, so vulnerable to oxidation when faced with too much light.
But here’s the real plot twist: sparkling wines, especially the bubbly rosés, are the ultimate victims of lightstrike, with the bubbles magnifying the damage. Those clear glass bottles (cue dramatic music) offer zero protection against UV light, leaving our precious wines defenseless.
How to prevent lightstrike?
The key to preserving your wine in prime condition lies in the cool, dim depths of underground cellars. It’s not just sunlight you need to worry about—those sneaky fluorescent and incandescent lightbulbs also emit UV rays that can harm your beloved wine.
Use LED lights, the champion defender of wine cellars! These efficient lights not only minimize UV emissions but also generate minimal heat, ensuring your bottles stay refreshingly cool.
Yet lights in the bottling line, in shops, bars and supermarkets can wreck havoc too. Imagine bright lit supermarket isles and display cabinets showcasing wine bottles with light.
The solution? Coloured glass wine bottles!
Clear glass only protects wine from about 10% of the harmful light; green glass 50%, and unfashionable amber glass offers 90% protection!
Problems with uncoloured glass
To illustrate this point, one study of glass bottles on supermarket shelves, found that lightstrike occured in some wines in clear bottles after just 1-2 days. But all of them developed the fault after 20-40 days. The green glass offered protection for up to 50 days.
On the other hand, volatile sulphur components (stinky stuff) can be formed even within 1 hour of exposure.
SommWine Tip
- when buying wines from a display fridge, pick bottles that are placed a few bottles away from the light source. Usually, this means a few rows back as the lights tend to shine on the first row. This way, you’ll lesson the chances that you get a bottle with lightstrike.
Famous Champagnes are taking note...
Some wine regions are aware of lightstrike issues. Therefore, we can all raise a glass to Champagne producers for stepping up to tackle spoilt wine.
For example, Louis Roederer’s Cristal, the top-tier cuvée, stands out because they still use clear glass bottles by tradition.
Legend has it that Tzar Alexander II requested this design to ease his fears of poisoning, as clear glass allowed him to inspect his bubbly for any suspicious colours.
Today, Roederer keeps the clear-glass tradition alive, but adds a modern twist: orange cellophane wrapping to protect the wine from lightstrike.
Furthermore, Ruinart recently launched this eco-friendly ‘Second Skin’ for Earth Day in 2021.
Other Champagne brands sell bottles in individual boxes to protect them from harmful UV light. Did you ever notice all the boxes before New Year’s Eve?
Armed with the knowledge of lightstrike’s causes, prevention strategies, and recognition techniques, you’ll be better equipped to savour your favourite bottles without the interference of this common issue. As this fault happens primarily on store shelves, it’s up to YOU to know whether a bottle tastes the way it should. So, in the future, use our tip and stop buying the first wine on a shelf. And here’s to raising your glass to a future free from the shadow of lightstrike, where every sip is a delight.
Never drink a faulted wine again!
Start here with one of my online wine courses!
A basic level course for those wanting to dip their toes into the world of wine.
4-week course
followed by exam
An intermediate level course for those wanting to to dive head first into the world of wine.
5-week course
followed by exam
No comment yet, add your voice below!