1. the first glass has a very dark extraction, and will taste the sweetest of the three
2. the second glass will be a little more tart and lighter in colour
3. the third glass will be the most tart of the three and the lightest in colour.
When extracted into a single cup, the difference is barely noticeable as all the flavours are blended together in the cup, but when separated in this way, you can taste the differences quite easily.