İlker

The physics of why ethanol cubes are impractical is decisive: its freezing point is around minus 114 degrees Celsius.

That is far colder than a domestic freezer, colder than dry ice, and reaching it requires specialised equipment. So pure alcohol cubes are not something anyone is making at home.

A cube of a mixture — a spirit, which is mostly water — freezes at a temperature that depends on its strength. A typical spirit at forty percent will freeze somewhere around minus 27 degrees, which most domestic freezers cannot reach. Weaker mixtures freeze higher and are achievable.

And if you did have very cold alcohol, handling it would be genuinely hazardous — liquid at that temperature causes serious cold injury on contact, and it does not feel cold in the way ice does until damage is done.

Stop tasting it and start measuring it, because taste is the least informative tool available here.

A hydrometer is inexpensive and tells you exactly what is happening. Take a reading now, and another in three or four days. If the number is falling, fermentation is proceeding and there is nothing to fix. If it is unchanged over several days at the same temperature, it has finished or stalled — and comparing the reading with your starting gravity tells you which.

If you did not take a starting reading, you can still work forwards: a stable reading over several days means it is done, whatever that number is.

Watch the airlock as a free secondary signal. Any bubbling at all means activity. But the reverse is not reliable — carbon dioxide takes a long time to clear and a lack of visible bubbles does not prove fermentation has stopped.

Which gives you two things to change, and they are both about the extraction rather than the finish.

Use the strongest alcohol you can get. High-strength neutral spirit strips far more oil from the peel than a standard 40 percent spirit does. This is the single biggest factor and it is why the traditional method specifies it.

Peel thinly and use plenty of it. Only the coloured zest carries the oil. White pith contributes bitterness and no oil, so a thin peel and a generous quantity of lemons is what gets the yield up.

Steep long enough for the alcohol to work — several weeks is typical — and keep it out of light.

Then when you dilute with syrup, the drop in strength does the rest by itself. If you have extracted well, the transition is dramatic and happens as you pour the syrup in.

It is not dairy. The cloudiness in the standard version is an emulsion of citrus oils, and the effect has a name: louching.

The oils in lemon peel dissolve readily in strong alcohol and are essentially insoluble in water. While the infusion is at high strength they stay in solution and it looks clear. When you dilute it with sugar syrup, the alcohol concentration falls below the point where the oils remain dissolved, and they come out as microscopic droplets suspended through the liquid — which scatters light and gives that opaque creamy look.

This is the same phenomenon as certain aniseed spirits turning white when water is added, and it is a genuine physical transition rather than an additive.

So if yours stays clear, one of two things is happening: not enough oil was extracted, or the final alcohol strength is still high enough to keep it dissolved.