This is a much better idea than keeping the juice inside the lemons, as they tend to mix with juices from other parts of the lemon and change consistency.
What other parts of the lemon have juice?
The peel area, which tends to become bitter if kept for long in the fridge.
I'm just speculating now, but it might be having reactions with other cells in the lemon, causing the taste to change.
The only thing that is for sure is that the test of the juice drastically changes if kept for long (even if in the fridge), whereas it doesn't, if squeezed out beforehand and then kept in another container, in the fridge.
This is a much better idea than keeping the juice inside the lemons, as they tend to mix with juices from other parts of the lemon and change consistency.
What other parts of the lemon have juice?
The peel area, which tends to become bitter if kept for long in the fridge.
I'm just speculating now, but it might be having reactions with other cells in the lemon, causing the taste to change.
The only thing that is for sure is that the test of the juice drastically changes if kept for long (even if in the fridge), whereas it doesn't, if squeezed out beforehand and then kept in another container, in the fridge.