Good for you on pointing him in the right directions!

In this specific case, since it was a minimal 1:1 brine to begin with, the addition of the soy sauce wouldn't be recommended either. But the risk is minimal assuming he used 5% vinegar and that the brine was hot when poured into the jars (cold brine would require longer processing).

Pickling recipes allow us some room to experiment but it doesn't mean we can jump out of the box and into the fire. :-)

Dave

My concern is that the brine was diluted from the cucumber juices since he didn't salt/drain first? Or doesn't this come in to play when you pickle whole cucumbers?

<Or doesn't this come in to play when you pickle whole cucumbers?>

Not really. There are many whole cuke pickling recipes that don't call for pre-soak. Only way it can work is when you cut some slits in the whole cukes to begin with. But they always call for more than a 1:1 vinegar brine to compensate for the extra water in the cukes.

So if he was home with them and they had just been done then I'd recommend opening the jars and adding some more vinegar to them.

If he gets them in the fridge and doesn't keep them for more than a week or so the risk is minimal. Personally I'd dump them but it boils down to his choice whether to eat them or not now.

Dave