Beni shōga is one of my husband’s favourites but I’ve never seen it without sweeteners and/or other unappealing chemicals.
There is a strong demand in France for high end Japanese ingredients and it can be easier to source less processed food there than in the UK. Even so, beni shōga only really tastes authentic when it has loads of additives in it.
Here are two brands that don’t seem to have sweeteners in them:
https://www.satsuki.fr/en/tsukemono/...hoga-200g.html
https://www.nikankitchen.com/en/prod...M-GB_OtpJhTUrC
It’s one of the few foods I can’t make myself, even if I use umezu it just doesn’t taste of beni shōga. I’m resigned to the idea that what makes julienned ginger taste like beni shōga and not pickled gari is in those additives.
EDIT TO ADD
As a FYI, Japanese people who are conscientious about avoiding additives generally tend to avoid beni shōga in Japan also. This is as much to do with the pesticides used on grown ginger as it is with the food colourings and sweeteners that go into preparing it. On those rare occasions when you do see organic “red ginger” it tends to be quite pale. Personally, I usually like pickled ginger but can’t stand the conventional beni shōga my husband adores. Since I tend to enjoy the organic, pesticide and additive free preparations, that’s my indication that they don’t really taste like typical modern beni shōga.
If you translate this page
https://kanazawa-organic.com/wp/wp-c.../05/161102.pdf it will give you a summary of why beni shōga is often avoided by those looking to consume less additives and pesticides.