Another one who grew up with only oil & now eats only water. I think they packed it in oil because it helped with the preservation. I don't know for sure, though. They pack sardines with oil, too. My mother started buying the water-pack for us when we were in college. (Back in the dark ages & we had no refrigerator to keep mayo!) That was the first we ate tuna with only pepper - before that we'd always used Miracle Whip.
Haven't tried the bags, but am wondering . . . why is the Albacore different? I always thought it was a specific type of fish - not the packing. I've been irritated in recent years because the tuna is so soupy when you open it & it splashes all over! When I'm home I throw it in the colander, but you used to be able to just drain the water by putting the lid on top & tipping.
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