I was also wondering if I could ask you a bit about gin louching. I usually ask people on the distilling subreddit when I have questions about distilling and you’ll be pleased to know that you are very popular on reddit, and are often mentioned by other distillers on there. One person said I should ask you directly.
I have had some issues with the gin louching when I add water to it. We usually distill 18L of botanical distillate at 78% abv and then add NGS at 96%abv and de-ionized water to bring the volume up to 200 liters and 40% abv. I have the following questions:
1) Does it matter how quickly I add in the water to the alcohol? Someone told me to add in the water slowly to avoid louching.
2) I’ve read that making a heads cut during spirit collection helps to prevent louching. I started taking 100mL off, and I do notice there are a lot of oils in it. Why is that? I thought the heavier oils would be in the tails, so why are there so many oils at the beginning of spirit collection?
3) I know that making a heads cut during spirit collection, making sure the spirit and water are around the same temp when mixing, and adding more neutral grain spirit to the final product help prevent and get rid of louching. Are there any other ways to get rid of louching?
Any advice would be appreciated. Thank you.
Hi there, dunno what Reddit is, but happy to be of assistance. If I should help the broader Reddit community let me know.
As for your questions:
- No. Quick dilution will cause temporary haze due to alc and h20 not being mixed, so spots have more or less alcohol. The “parts” with less alcohol have less solvency power and that’s what causes the temporary louching.
- Takes time for the column to heat-up. So the first fractions are going to be distilled many times by the time they come over. Gas rises, hits a cold column and returns to liquid, giving off its energy and heating up the column, while performing basically a distillation. This process leads to over concentration of early juniper oils and they need to be discarded. Often you can see the oils float like a ball in the middle, if you collect heads in a see-through glass.
- You see louching as a problem. It isn’t. It is a sign you got tremendous amounts of flavor over. Congrats. Now mix in 40% ethanol/water mixture to add solvency power. When the haze lifts you achieved a gin with maximum taste saturation. Pls. know that 43% for craft distilled is often better due to higher solvency power. Otherwise a slightly earlier tails cut or a slightly lower run. But that is if you continue seeing louching as a problem, which it really isn’t.