Learning about Distillation

Sometimes it feels like everything that you’ve learned across a whole range of subjects all comes together in one area. For me right now this is learning about distillation. It brings together my interests from biology and chemistry to gardening and horticulture to history and craft to preserving and making things. I’ve always been intrigued by distillation but assumed that you had to have large expensive gear and very specialist knowledge to do it.

More recently I’ve learned that you can experiment with many aspects of distilling (and get good results) with small relatively inexpensive equipment. I have ordered a small still (which will hopefully arrive in August) but meantime I attended a workshop that covered all the different aspects of distilling.  Jill Mulvaney from Alembics is a craft distiller with over 25 years experience. She teaches and consults on all aspects of distillation, aroma and natural flavour, advancing ideas and products that can be utilized across a range of industries: spirits, perfumery and cosmetics.

First a bit of the history: distillation has been used for centuries. The first alembic still was invented around 200 AD by Egyptian and Arabic alchemists who used copper stills to create fine balms and perfumes and even used them in their quest to convert base metals into gold. They created alcoholic liquor from fermented materials such as grapes and separated out aromatic floral waters and essential oils from a range of different plants.

A bit of the craft: The making of the copper stills itself is an ancient craft with such skill in the bending and shaping of copper followed by beating to harden it. And the shapes of the stills are just beautiful – they are pieces of art in their own right. Even if I decide that distilling is not for me, I will be delighted to have such a beautiful piece of equipment on display in my home.

A bit of the science: at its most basic, distillation begins by heating water and botanicals in a pot still. As the temperature rises the most volatile constituents of the water/plant mix begin to evaporate. Vapours accumulate in a dome and find their way down to a condensing point via a connecting tube or swan neck. In a traditional still the swan neck leads to a coil in a condenser filled with circulating cold water. Once the vapours come into contact with the cold surface they condense to their liquid state and trickle down to be collected in a glass beaker drop by drop. The essence of the plant or flower is now captured in a liquid form, which is referred to as the distillate.

A bit of the technical: there are different types of stills that you use for different purposes:

• Traditional Alembic Stills are used for the distillation of hydrosols and spirits, using a process called hydro-distillation where plant material is immersed in water in the pot rather than being subjected to steam.
• Alembic Column Stills have an extra middle section and are used for steam distillation to produce essential oils: plant material is placed in the column and sits above boiling water in the pot so that it is subjected to hot steam, releasing volatile oils. You can also use them as a finishing still using a neutral spirit in the pot and botanical blends in the column to create your own gins and other spirits.
• An Alquitar is a different design of still primarily for the production of high-quality artisan spirits such as brandy, grappa, calvados and eau-de-vie. It can also be used for hydrosols, gin and for the distillation of aromatic woods, barks and resins.
• I have bought the smallest 2.5l Alembic Column Still that is referred to as an ‘appliance still’ and can basically be used for a little bit of everything, perfect for trying it out and working out what you most enjoy doing. Although you can distill alcohol, you wouldn’t use this still to produce neutral spirit but would start with vodka for example and add the botanicals. If you did want to produce your own neutral spirit it would be better to start with a 30l Alquitar still.

A bit of the biology and gardening: one aspect that really appeals to me is being able to distil products that I’ve grown in my own garden, whether that be a rose geranium or lavender hydrosol or my own signature gin reflecting my garden. But as Jill explains to us, it is not just a matter of using your prunings when you are having a garden tidy up, you really need to understand your plants and what they are doing at different stages e.g. are they establishing their roots and producing volatiles to keep away bugs in the soil (a good time to harvest root material for distilling) or are they producing lots of volatiles in their leaves; are the flowers producing volatiles to attract pollinators (perhaps they are wind pollinated and don’t produce attractant volatiles) or are they past their prime and so of no use for distillation. You also need to know what species of plant you are dealing with and whether it will give you the product you are anticipating e.g. have you got peppermint, spearmint, apple mint, wild mint etc. Not all species of plants will give a (nice) distillation product.

A bit of the art of distilling and blending: whilst you follow recipes and instructions full of weights, volumes, percentages, temperatures, and hydrometer readings, there is so much more to the process than that! And you need to experiment and build experience so that you can trust your sense of smell and sense of taste, trust in your judgement about how much to use of what, what combinations work best, and even when to just start again.

Thanks to Jill for the extremely informative (and somewhat mind-boggling) workshop. It was a great day – held at the Auckland Botanic Gardens. We had 30 or so people from all around NZ (none from Australia this time) and from a wide range of backgrounds: several had lifestyle blocks, some with horticulture backgrounds and some keen gardeners, a biology teacher, someone who wanted to use up a lot of cheap red wine, and a couple of accountants that didn’t have a garden or any knowledge but thought it sounded fun. We learned how to make a hydrosol from kawakawa and lime, how to produce essential oil from rosemary, and how separate out eau-de-vie (a neutral spirit) from some cheap red wine.

So much information to take in and so many things I’d like to try. I am both terrified and excited to start down this journey to see what I can create.