Warning to anyone who drinks espresso martini after bombshell over key ingredient

For a welcomed change, we've been enjoying a nice amount of sunny spells as of late and what is the number on pastime us Brits love to do when the sun's out?

Have a cocktail.

From cheap and cheerful happy hour offerings to the most artistic (and expensive) creations - it's clear many of us love a good Cocky T or two.

However, a warning has been issued to anyone who drinks espresso martinis after a bombshell discovery over one key ingredient.

Espresso martini guzzlers, you've been warned. (Dejan_Dundjerski / Getty Images)

Now, for me, the humble espresso martini is everything you'd want in a glass: booze, sweetness and a healthy dose of caffeine.

Usually compromised of vodka, coffee liqueur, espresso and a simple sugar syrup - this cocktail really epitomises the whole 'less is more' school of thought when it comes to mixology.

But, what a lot of people don't know, is that one popular coffee-flavoured liqueur is actually not suitable for some dietary requirements.

From White Russians, Black Russians, Mudslides and - of course - espresso martinis, Kahlúa is used in a wide array of cocktails.

However, those leading a meat-free lifestyle may want to check the cocktail's ingredient list as Kahlúa is not actually suitable for vegetarians - a change that was made almost a decade back.

A key ingredient used in espresso martinis, Kahlúa, isn't actually suitable for vegetarians. (Lemanieh / Getty Images)

Confirming the news in a statement issued to mobile cocktail bar, Spin and Shake, Kahlúa explained the reason for this is due to the sugar refinement process of all things.

"We can confirm that Kahlúa is NOT suitable for vegetarians or vegans. This is because of the sugar refinement," it said.

"It appears there was some confusion as, prior to 2016, Kahlúa was deemed suitable. At this time, Kahlúa is not suitable for vegetarians or vegans."

Craig van Niekerk, global vice-president of marketing for Malibu and Kahlúa, said: "We can clarify that Kahlúa is not directly manufactured with any animal derivatives. However, it’s important to note that a bone char filtration process, which does involve contact with animal derivatives, is employed by one of our sugar suppliers during refinement.

"This widely accepted practice in the sugar industry currently prevents us from categorising Kahlúa as suitable for vegetarian and vegan diets."

Kahlúa goes through a 'bone char filtration process'. (jackmalipan / Getty Images)

The brand also confirmed that the same applies to Malibu, the beloved coconut-flavoured liqueur made with white rum, natural coconut extract, and sugar.

However, a bespoke vegan version of the product was made for its recent UK collaboration with Oatly so that's a start!

Upon hearing the news, espresso martini drinkers have taken to social media to share their frustrations.

One X user hit out: "I feel like the absolute most f**king stupid non-vegetarian things I know of are Kahlúa and most wine.

"Why the F**K are you filtering s**t with animal bones and swim bladders?? What the F**K??

"How did you manage to arrive at booze that isn't even vegetarian, let alone vegan??"

Another penned: "I just found out Kahlúa is not vegan anymore.......don't text."

"Damn, who knew that Kahlúa by itself is not vegan? Glad I checked before I indulged," echoed a final X user.