Distillers like Taweechai Thongrod often see their work as part art and part science.
"You need art because it's what sells your product. It's what makes people feel connected to what they are drinking," he told the ABC.
"But the science is also important because it's for the sake of safety, and for a distillery to make a consistent product, you will need background science."
The owner of Sangvein Distillery in central Thailand knows just how delicate the process can be.
If you get it wrong, the results can be deadly, as seen in the recent spate of fatal methanol poisonings in Laos.
"For first-time distillers, it is very highly likely that they might poison themselves," he said.
"So I really recommend first-time distillers study the theories and the scientific background first very carefully."
The fine line between danger and spirits
The aim of distillation is to create ethanol, a drinkable version of alcohol.
But there are other chemical compounds present that can be dangerous to consume and therefore must be removed.
Methanol, the poison that killed six tourists in neighbouring Laos, including Australians Bianca Jones and Holly Bowles, is the biggest risk in the distillation process.
To minimise it, Mr Thongrod says distillers must follow a relatively simple step.
"The methanol, which is the lightest of all the alcohol, comes out first. So that's where the 'foreshots' is," he said.
"It's customary for distillers to ditch the very front-most part, the 'foreshots'.
"It's only a tiny amount, like from 1,000 litres distilling, you might just ditch about 300 millilitres. It's that tiny, but that's where most of the risk stays."
Every distillation results in what alcohol producers call foreshots, heads, hearts and tail.
"When the distiller thinks that it's gone to a safe section, we cut that off, we dump the foreshots, and that becomes the 'heads', which is where the flavour goes," Mr Thongrod said.
"And then when the flavour kind of goes away more it becomes a more neutral, smooth spirit. That's the 'hearts'.
"And then goes the 'tail', which is more pungent. You can drink some of the 'heads', most of the 'hearts' and some of the 'tails', but you definitely would dump the 'foreshots'."
Knowing where to make those cuts is crucial, and largely comes down to knowledge and experience.
Licensed distillers, such as Sangvein, also have to send their products to a lab for regular testing.
"It's a bit of a hassle, but I think it's a good way to make the consumers know that what they're drinking is actually safe," Mr Thongrod said.
The cause of the methanol poisoning outbreak that killed six tourists last month in Laos is still being investigated.
But a government document obtained by the ABC suggests the alcohol came from a rundown factory outside the capital, Vientiane, that was making vodka and whisky.
The owner of the factory has been arrested, as well as 11 staff members from the Nana Backpackers Hostel.
Mr Thongrod is disappointed the scandal in Laos is tarnishing the local industry.
"We do everything by the book. All our alcohol has to go through the excise department," he said.
"We have regular lab tests, so we are safe. But because it's about alcohol, the public opinion or the panic that comes after it, they see all alcohol makers as bad people."
'Sometimes everything will go wrong'
There are many variables in brewing and distilling that can impact the safety of the product, according to Ian Musgrave, a senior lecturer in pharmacology at the University of Adelaide.
"Sometimes your brew could come out fine. Sometimes your brew can come out with high methanol. It's very hard to control," he told the ABC.
He said hygiene, temperatures and raw materials could all be the difference between a safe and poisonous brew.
"If you've ever done the sourdough bread, if you get a bad batch of starter, everything can go wrong. Same with this," he said.
"It can be just an accidental thing, that you've got the wrong yeast or the wrong amount of pectin in your starter material.
"Even if you know what you're doing, sometimes everything will go wrong."
Dr Musgrave said some bootleggers missed the crucial step of removing the part of the brew with the highest concentration of methanol — sometimes out of greed, sometimes out of ignorance.
"If you're distilling carefully, you can pull off the methanol and just have ethanol. But if you're not paying any attention to it, you can get a quite lethal brew out of it," he said.
Some bootleggers also add methanol deliberately as a cheap way to boost the alcohol concentration of their product.
This is what police have accused two men of doing in Bangkok earlier this year when a bad batch of moonshine led to another methanol poisoning cluster that killed 11 people and left dozens more in hospital.
Dr Musgrave said the recent case was a reminder to be wary of what you drink in countries with poor alcohol regulation.
"The sad fact is that you should preferably buy sealed containers of spirits and make sure that you only drink from reputable bars," he said.
"This is directly contrary to the spirit of adventure, but this is what you need to do in places where there's not careful regulation of alcoholic beverages."
