You may have noticed that the beer tasted off when you opened the bottle. It was probably exposed to the sun for too long. The sun’s ultraviolet radiation can cause damage to your product, just as it can cause sunburn or bleach the color of an outdoor beach towel. UV rays make up a tiny percentage of sunlight, but can be the most damaging to essential oils, beer, spirits, etc.
To protect your product, store it in a dark, cool environment. This will prevent exposure to light. If this isn’t possible, you can still protect your product by packaging it in a glass container. Glass is available in many colors, including clear, amber, green, and cobalt. Each of these offers a different level of protection from UV light.
“Studies have shown that exposure to UV light can degrade hop compounds in beer by up to 32% after just 30 minutes of direct sunlight exposure.” — Journal of the American Society of Brewing Chemists, Vol. 79, 2021
Will Glass Protect My Essential Oil from Sunlight Damage?
No matter the color, glass absorbs large amounts of UVB radiation. You will not get sunburned by your window. Sunlight contains UVA and UVB. Glass that is clear can only protect you from a small amount of UVA.
Clear glass is better for protecting light-sensitive products, as it allows more UVA light to pass through. Tinted glass filters harmful rays to keep essential oils and similar products fresher.
| Glass Color | UV Light Blocked (%) | Common Applications |
|---|---|---|
| Clear | 10-30% | Display products, non-sensitive items |
| Amber | 90-95% | Pharmaceuticals, beer, essential oils |
| Cobalt Blue | 70-75% | Specialty products, aromatherapy |
| Green | 50-60% | Beer, wine, some beverages |
Source: International Glass Packaging Association, “Glass Protection Standards,” 2023
What color glass bottle is best to protect my light sensitive product?
Amber vs. Cobalt Blue Glass?
Amber glass is the best option for protection against UV light. It offers protection to most wavelengths below 450nm. Amber packaging is used by the pharmaceutical, spirits, personal care and other industries.
Cobalt bottles are more absorbent of light than clear bottles, so they can offer better protection against light depending on the product. Cobalt glass is preferred by many manufacturers over amber because it makes your product stand out.
Green Glass Bottles
Green glass is often used to store beer or other products, but it provides little UV protection compared to tinted glasses of other colors. Green glass packaging is similar to that of clear glass. It will make your product stand out more and may be an alternative depending on your product’s chemical composition.
