How long does Chouchen keep once opened? I have tried to look this up but have only come up with a few community sites with improper sourcing and varying degrees of answer (from 1 month to many years).

Does anyone have first hand knowledge or a reliable source?

The back of the bottle is written in Breton, which google translate doesn't support, but since it is close to French I think this is the line I am looking for:


  Conservation du chouchen une fois ouvert des annees.


Which to me sounds something along the lines of 'once opened keeps for years', but it's just a guess. 

I also know this is the Breton equivalent to mead, but I believe it's made with apple juice which I assume will make it go off faster. 



Update: I opened this bottle when I posted this question, forgot about it in the cupboard and remembered it again over the weekend. It tasted absolutely fine (or at least the same as it did when I opened it). I will add an answer when/if the taste changes.
I had to look up Chouchen as I'd never heard of it before (see, after many years still learning!) It looks like it's a form of mead made out of Buckwheat honey which gives it that dark color and probably stronger flavor. According to the article, it was originally made out of cider and honey but it looks like both versions are called Chouchen now. I looked around on the internet and saw that they were generally 13-14% ABV which is in the normal strength for wine and mead. Mead, cider and wine all can last many decades. But as with all of them, once the bottle is opened it will go bad within a few days from oxidation.