A European cucumber is considered a regular cucumber where I live, we get them at any organic supermarket year round. There are few different varieties we can get from the organic market in the summer, but the cucumber is what we mean by cucumber.
Picking the best cucumber
Frische, knackige Salatgurke sehen frisch und knackig aus. Keine gelben Stellen, keine schrumpelige Haut. Zur Not kann ich die Gurke am Strunkende anfassen und fühlen, ob diese schon etwas weich ist. Dann ist diese nicht mehr so ganz frisch.
You can spot a fresh, crunchy cucumber by its looks. No yellow spots, no dry or wrinklely skin. The end, where the flower would be, dries and softens first. B touching it, you can tell if the cucumber is still firm or has been sitting in the store for too long already. Also the other end, where the cucumber was attached to the plant dries faster than the middle part. Squeeze it generally.
When I have an older cucumber sitting in the fridge, of course I will still eat it. But if I had the choice, I would not buy a soft cucumber.
The slizer I have in the photos is from Japan, it looks great in photos, but from my experience, any slizer will do, they are sharp, affordable and handy. I would definitely recommend a protective glove (special safety glove, not just the the latex food prep one) when using a slizer, mandoline, or julienne slicer.
Storing a cucumber at home
Cucumbers do not store super well. If the cucumber is still in a good shape, it will last couple of days. A cucumber does not like to linger on a the warm kitchen counter. It also does not enjoy sitting in a cold in the refrigerator.
I always try to use the cucumbers first before getting to the other veggies. I would never try to store a cut cucumber.