1. The buffer bottle
Nominate one bottle as a temporary store and try not to finish a colour in it. Its job is to absorb the odd units that sit on top of things you need. The trick that makes a buffer cheap is to reuse it: park a yellow there, and then send every other loose yellow to the same place, so the space you spent serves the whole colour instead of one unit.
When it applies: boards with exactly one empty bottle. Risk: if you park two different colours in the buffer, you have destroyed it — the lower one is now trapped.
2. Consolidation
Before spending any space, sweep the board for pours that merge two fragments of one colour where the whole block fits. These moves are free: they reduce fragment counts without committing universal space. Always take all of them before moving on to anything speculative. On a six-colour board there are often three or four such pours available at the start, and finding them turns a scary board into an ordinary one.
3. The chain pour
A chain is a sequence where each pour exposes the colour needed by the next one, ending with a bottle completely empty. For example: pour A's single green onto B's green, which exposes pink in A; pour A's pink onto C's pink, which empties A entirely.
Chains are how you regain empty bottles in the middle of a board. When you are looking for a move and nothing obvious exists, look specifically for a bottle whose contents are only two colours — those are the candidates for a two-step chain that ends in an empty bottle.
4. Reverse solving
Start from the end state and ask which bottle will hold each colour. Then, for the colour you care about, ask what must be true immediately before the final pour. This often reveals that a specific bottle must be empty at a specific time, which in turn tells you what not to pour into it now.
Reverse solving is most useful on hard boards with one spare bottle, where the last four or five moves are heavily constrained and the opening looks wide open. Work out the ending first, then the opening that reaches it. The planning routine uses a light version of this.
5. Space accounting
Count two numbers before a risky sequence: how many units you need to park, and how many free units are reachable by those specific colours. Reachable means the space is in an empty bottle, or on top of the same colour. If the need exceeds the supply, the sequence fails — no amount of clever ordering saves it.
Quick check: a colour buried under three different colours needs three parking places, and each must be usable by that colour. Two empty units plus one space on top of a matching colour counts. Three spaces above one unrelated colour does not.
6. Deadlock detection
You can usually see a deadlock two or three moves before it happens. The signal: the number of distinct top colours is rising while your universal space is falling. If every bottle shows a different colour and nothing is empty, there are no legal pours at all.
The counter-move is to keep at least two bottles showing the same colour on top at all times. That pair is your escape hatch — a guaranteed legal pour that also reduces a fragment count. Losing the last such pair is usually the real moment a board dies, several moves before it becomes obvious.
Putting them together on a hard board
- Consolidate everything that is free.
- Account for space before touching the empty bottle.
- Reverse-solve the colour you intend to finish last.
- Use the empty bottle as a single-colour buffer, not a dumping ground.
- Look for a chain that returns the buffer to empty.
- Keep one matching top-colour pair in reserve at all times.
Levels 21 to 30 in the browser game have seven or eight colours and only one spare bottle, which is exactly the setting these techniques were written for. If one of those levels is beating you, the walkthroughs show a full solution line.