I don’t know how to tell you which one is which. But I compare them visually and I know two.
The one with red flesh, and the one with yellow flesh. (Could be the same one at different points in its life)
My baseline is the plums I ate growing up in Argentina.
The red ones are full of flavor, especially when ripe. The softer they get the juicer and sweeter they get. These are bigger in size.
The yellow ones are more acidic, but get sweeter as they ripen. Also good. Smaller in size, I can fit a whole one in my mouth.
I find the same red/yellow variants in the US. But without the flavor. They are also flavorless no matter what stage you eat them at. Ripe, not ripe, all the same: water.
The yellow ones are just bleh. Acidic without the good side.
I gave them plenty of chances at different times of the year and in different locations. The best ones I had were in upstate NY in September, but still about 7/10ths of the flavor of the ones in South America.
Your description fits well with a 'Golden Japan' (or 'Sungold') and a 'Methley'. Both are standard quality Japanese. Probably picked too early if they lack sugar (or cultured in an cloudy place, or stored in a fridge for too long...). The problem with spring fruits is that they need a long spring to be really good.
The one with red flesh, and the one with yellow flesh. (Could be the same one at different points in its life)
My baseline is the plums I ate growing up in Argentina.
The red ones are full of flavor, especially when ripe. The softer they get the juicer and sweeter they get. These are bigger in size.
The yellow ones are more acidic, but get sweeter as they ripen. Also good. Smaller in size, I can fit a whole one in my mouth. I find the same red/yellow variants in the US. But without the flavor. They are also flavorless no matter what stage you eat them at. Ripe, not ripe, all the same: water. The yellow ones are just bleh. Acidic without the good side.
I gave them plenty of chances at different times of the year and in different locations. The best ones I had were in upstate NY in September, but still about 7/10ths of the flavor of the ones in South America.