Distillation

As in collection where seasonal time of harvest, even sometimes time of the day, as well as the plants developmental stage matters, each plant after collection as well has its specific requirements. Some plants need to be distilled fresh, some have to be dried, some semi-dried first, some need to be comminuted- cut into smaller pieces-, some need to soak for some hours before distillation.

Then each plant has different distillation parameter requirements.

We have spent our first early years experimenting with the different conditions needed for truly to honor and respect each plants individual need. After all, they were harvested to fulfill a purpose, to give us their essential oil, their spirit, their soul so to speak. So in turn, we feel obliged to fulfill our part of 'the deal' by creating the most favorable conditions.

Most of our plants are distilled with so-called water-steam distillation. We have chosen this method instead of direct-steam distillation, because it allows for the most gentle process at atmospheric pressure and at temperatures well below 100°C, that is around 96°C. This method prevents the overheating of the plant material, provided the retorts are well insulated, so that the fire below only heats the water, but not the sides of the still. However, this method is seldom used commercially, because the gentler parameters mean a substantially prolonged distillation time. In addition it requires knowledge that only comes from experience with your still and its adjustments in relation to the heat applied and the requirements of each individual plant, that is, you cannot just leave the still, each distillation is a living thing, an act of alchemy. Not just a mere press on a button on a separate steam generator, and a timer set for the shortest possible time.

So, first a basic introduction to our stills and the distillation process

 

The still, the grid inside the still and the funnel and florentine vase

So here is a schematic outline of our stills.

The retort is of stainless steel, build into a stone-oven like structure, however, only the very bottom is heated by the fire. The sides are insulated from the outside. In the case of a water-steam distillation, we fill the water, then fit perforated stainless steel grids into the retort, well above the water level. You can see the grid inside the retort in the picture above.

The plant material is fitted tightly and uniform into the retort. The steam passes through the plant material, carrying the volatile compounds with it. Moving upwards, the steam and essential oil moves through the 'gooseneck' towards the condenser unit, a stainless steel coil immersed in water. The condensation process has to be gentle, to avoid that the oils 'burn' on a pipe too hot which can happen if the water in the cooler gets too hot. Therefore one has to adjust the cooling water temperature. This is done by a constant flux of water. Cold water is added from the bottom, hot water allowed to flow out from the top, as the water always be hotter in the beginning of the cooling process, that is on the top where the condensation process starts. The adjustment of the cooling water flow is an important part of the process.

The condensate liquefies during it travel down the coil towards the exit. Here, it is collected in the first separator, the so-called 'florentine' vase. This device is pictured separately above, and designed to separate the essential oil, being lighter than water, from the hydrolate, hydrosol or floral water. This device has two outlets. One at the top, which remains closed during distillation, and one on the bottom. The latter one curves upwards, and is open during distillation. Through a funnel the condensate fills the florentine, and the essential oil collects on the top. When the liquid in the florentine reaches the upper curved level of the lower outlet, the hydrolate below starts to flow and is collected continously, whereas the essential oil accumulates in the top region of the florentine, from where it can be collected from the top tap. For the final separation we use a glass separator, which will be seen later.

Well, here we start, back at the distillery. The herbs have arrived in their boxes, or have been dried in our drying room adjacent to the distillery. The herbs dry at the natural surrounding temperature, we do not use any heat. But then again, we are in Crete, blessed with a mild climate.

 

Thyme tops (left) and Lavender tops (right) in boxes

 

Here thyme tops are ready for distillation and filled into the stills

Then the retorts are filled. It is important that the material is filled uniformly and well packed into the retorts, to ensure that the steam doesn't find escape tunnels through the plants without liberating their oil. So, sometime it needs a man or a woman inside the retort to press them well.

 

Here Babis is ensuring uniform packing of the plantmaterial

Then the gooseneck is closed, the condenser pipe attached to the cooling coil, and when it 'starts running' the cooling temperature is adjusted.

 

Its running...

When all is well set, the fire and cooling water finally adjusted, its time to have a tea, start preparing food and maybe have friends visiting to spend the many hours with us until distillation is complete. As mentioned before, gentle distillation requires its time. More often than not, its dark when the plants have given their essence to us completely.

A fast distillation might liberate the more volatile bulk of the oil, maybe even 85-95% of it, however it is just the least volatile components which elute later on, that have a profound role to play in the final product and which complete the oil. For commercial purposes, of course, it doesn't pay to distill for example for 4-5 hours, when it can be done in 15-20 minutes.

But for us in our work, as said before, it is important to allow the plant to express itself completely in its oil and not just to take the superficial bulk of it only, but also the finer and deeper expressions of the plant. This way, we are honoring its 'original instructions' as the American Indians understand it.

It is an experience to smell the distillate at different times during the distillation as it comes out of the cooling coil. As the individual compounds elute, the fragrances change. Distillation is the progress of different compounds eluting, and distillation is complete, when no more essential oil components elute.

Then it is time to stop the process and finally separate the complete oil from the hydrolate in the florentine vase, open the top tap and drain the oil into a glass separator for final separation from remaining hydrolate.

 

Here you can see the top tap of the florentine and the glass separator. In the first picture, we have drawn some hydrolate with the oil, to make sure not to have any oil left in the florentine. In the next picture, the hydrolate is drained off by the bottom tap of the glass separator, and we are left with the essential oil. This one is Lavandula stoechas.

Each plant gives its own yield, as you can see above, we can obtain about 5- 600ml from both stills together when we distill Lavender. For lower yielding oils, such as wild carrot seeds and myrtle we might get 3-400ml, and the lowest yield we obtain from lentisk, here we get around 250ml from a distillation. And it always takes some 44-48 boxes full of plant material to fill the stills...

Then the oil is transferred to a glass bottle and allowed to settle. After that the aromatic compounds originally in the plants have been separated from each other during distillation, they need to settle with each other again after distillation, become a unity again. And the fragrance of the oil develops with time. When the oil has settled, it is filtered to remove whatever trace there might be of hydrolate in it, then bottled and labeled by us.

After distillation the plantmaterial is exhausted there is just a faint smell of organic matter, serving as compost. Work not yet over, the retort has to be emptied and cleaned..

Spent Lavandula stoechas in the retort after distillation.

For the next days distillation of the same herb, we use a method called cohobation. Since some of the volatile compounds might dissolve into the hydrolate during the first distillation, we use the hydrolate from the first one as the 'water' in the next distillation. Since the hydrolate is already saturated, it will not take up any more volatile compounds which should be in the oil, and instead take up more of the water soluble compounds in the plants. This way, volatile compounds from the hydrolate are re-distilled into the oil, and as well as the hydrolate improves considerably in quality being such saturated.