Essential Oils

Wal writes ...
    A 5 litre still for extracting essential oil is legal in Australia.

    My understanding is that if you want the maximum yield, pot distillation is the method to use. Yields are below 5% therefore you need lots of material if you want pure oil and not just flavoring.

    For % yield from herbs and spices see http://www.switcheroo.com/Extracts.html
    For historical (Medieval) recipes see http://www.gallowglass.org/jadwiga/herbs/oil&water.html (and then select oils&water.html from the index).
    Type "essential oils" in a search engine.

    I have no personal experience in essential oil distilling except where I have distilled crushed aniseed, orange peel and lemon peel as part of the wash in a reflux still producing 70%abv, to produce raki and triple-sec. Tony Ackland (see Flavoring) uses a small pot still to produce a gin essence from botanicals specific for gin. Commercial gin distillers either macerate the botanicals in 45% alcohol by vol. and then redistill or pass the alcohol vapor through a suspended wire basket in (I suppose) the second distillation stage.

    This is what the instructions for an 'Essential Oil Kit Distiller' say:
      "There are 3 different methods to extract essential oils with your Still Spirits 5 litre Still.

      Method 1. Water dissolvable oils.
      Soak the material containing the oils to be extracted in water for 24 to 48 hours. Strain off the solids leaving just the liquid behind. Add this liquid to the still and bring to the boil. Make sure there is enough water flowing through the condenser to condense any steam which comes out of the condenser. Collect the distillate in 100 ml quantities. Test each 100 ml batch before combining to ensure quality is acceptable. As the condensate is driven off the nature of the oils will vary.

      Method 2. Steam dissolvable oils.
      Fill the still with 5 litres of water. Suspend the material containing the oils in a wire basket above the level of the water. Bring the still to the boil and collect the condensate which is produced. As the steam passes through the material, it will pick up the oils and carry them through with the condensate. Make sure there is enough water flowing through the condenser to condense any steam which comes out of the condenser.

      Method 3. Alcohol dissolvable oils.
      Soak the material containing the oils to be extracted in 50% by volume alcohol for 24 to 48 hours. Strain off the solids leaving just the liquid behind. Add this liquid to the still and bring to the boil Make sure there is enough water flowing through the condenser to condense any steam which comes out of the condenser, Collect the distillate in 100 ml quantities. Test each 100 ml batch before combining to ensure quality is acceptable. As the condensate is driven off the nature of the oils will vary."

    As the vapor consists of alcohol and water my view is that Method 3 would suit all herbs and spices. You would need to check this.
The third method is basically what I do when making gin essence from juniper berries in my wee stovetop still. It is simply a 1L glass coffee pot, with a large cork in the top, through which a condensor sits. Total cost < NZ$20.



Scrounge adds ...
    There are two methods suitable with a pot still - dry heat ( which doesn't work for many ) and steam distillation.

    I've found that rather than messying around with baskets to hold herbs about the steam it's perfectly possible to pack your still densely with the herb in question, add about 1/4 that volume water and distill slowly - the stuff that comes out the other end is a cloudy mixture of water and oils that soon settles out.

    There are very few oils that occur in decent quantities to be worth trying at home - Lavender, rosemary, mint and citrus peel all work well. Chamomile can be done if you use an alcohol maceration and keep adding replacing the chamomile, what you end up with is very pleasant smelling spirit suitable for addition to bath water or skin application. Incidentaly, chamomile comes off blue - just in case you worry what's happened to the still.
Jack writes ...
    ..I have come up with a winner. The small esspresso pots (that sit on your stovetop) that import/export shops carry are nothing more than a small steam still.

    They typically have a small lower chamber for the water, then a container that holds coffee grounds (the bottom is a perforated plate, keeping the grounds off of the water). Above this is a little spout that the steam (after going through the coffee) passes through, which empties out the espresso into the upper chamber. Look at what's available on the shelf at the store. Don't buy a coffee percolator- the thing I'm talking about allows only steam to pass through the coffee grounds (steam distilling the coffee). I bought one in the U.S.A. for $10 (it's a small 3 cup model), made of aluminum, and works great for steam distilling rosemary and lavender oil.

    When I pour the steam distilled product out of where the coffee normally is into a glass cup, these oils show up as an oil on water layer- to prevent them from going moldy, I add some petroleum ether (mineral spirits), shake in a sealed jar, then pour off the top (ether) layer and evaporate it, leaving behind the essential oil. I haven't tried it with cirtus, juniper, nutmeg, or anything else, but it should work for these plants/flowers.

    By the way- use distilled water for the best results.

Using Oils

Wal writes ..
    I am one who believes that using natural flavors is a great part of home distillation, and that valid flavor variations are superior to poor imitations. With this in mind I have been trying to rationalise the myriad of empirically based recipes. A good starting point is to find out the percentage yield of essential oil from the common herbs and spices used, as these produce the flavors. Knowing how much essential oil is required to produce the desired taste, we can work out the quantity of raw material required. We can macerate this material in alcohol and then redistill, adjusting the taste with clean alcohol, or we can add it to (or above) the mash/wash and distill together.

    A useful site for essential oil yield is: http://www.benzalco.com/ While there check out their pot stills. For details of herbs see: http://www.botanical.com.

    Recipes indicate that 7 drops of essential oil per litre of spirit is the minimum requirement. About 1/2tsp. of essential oil/litre of alcohol (40%abv) seems to be the optimum amount. To be safe, begin by using 1/8 tsp., then add more drops of oil until you are satisfied with the flavor. With anise oil you should not go below proof as the anise oil turns white in water. Extracts are essential oils diluted in alcohol and usually 4 units of extract is equivalent to 1 unit of essential oil. The S.G. of oil is about 0.8kg/l.

    Examples-
    • Anise flavor. Crushed anise seeds give an oil yield of 1.5 - 4%. Assuming a practical 2% yield, 100g of crushed aniseed for each litre of alcohol (50%abv ) should be sufficient.(about 2.5ml or 1/2tsp. of oil). Therefore adding 500g crushed aniseed to a 25l wash should be sufficient for the 5l of alcohol (50%abv) one can obtain. 2tsp. of aniseed weighs approx. 10g while 4 heaped tablespoons weigh about 50g.
    • Orange flavor. Citrus peels have a potential oil yield of 1.5 - 2%. The peel from one orange weighs about 50g. Therefore you need the peel of 3 oranges(150g) for each litre of alcohol (40%abv). This yields about 1/2tsp. of orange oil for each litre of alcohol. You can macerate this amount in alcohol to draw out the oil for liqueurs if you don't mind the orange tinge.
    • Lemon flavor. You need the peel of about 6 lemons for each litre of alcohol (about 2.5ml or 1/2tsp. of essential oil). Literature suggests that a 1000 lemons are required to produce one pound of essential oil. Macerate this amount in alcohol to make limoncello (750ml 40% alcohol,peel from 6lemons, 21/2 cups sugar, 21/4 cups water - macerate for 2-4 weeks.)
    • Gin. It appears to me from 2 sites that of the main ingredients you need are 25g of juniper berries and 12.5g coriander seeds for each litre of alcohol (45%abv). The oil yield from juniper berries is 1.5% and for coriander seeds its 1%. Therefore about 7 drops of juniper oil and 3 drops of coriander oil would be quite sufficient, together with small amounts of the other herbals. Dutch gin is stronger flavored, and historically used malted grains in the mash. The use of pure alcohol is a modern idea.
    • Oak. Wine makers use 1-5g of oak shavings per litre of wine, checking every 2 months until the desired flavor is obtained. A similar quantity would be appropriate for alcohol. American oak has more vanillins than French oak and is preferred for whisky, rum and bourbon. Scotch and rum is aged in casks which held oloroso sherry, and this can be imitated by soaking the chips in dry Spanish oloroso sherry before adding to the alcohol. Toasting oak produces sugars and vanillins, and adding toasted oak to make brandy quickens the process, as French oak being high in tannin takes a while to mellow.
    • Rum. You can use raw sugar to produce light white rums like those from cane syrup or use molasses (50% sugar) for stronger flavors. For the south-east asian arak you can use palm sugar which comes from Thailand and Indonesia and is sold in Chinese grocery stores. Use sherry soaked oak chips to produce gold rum. Add caramel to produce dark rum.
      This gives a good idea of typical ingredients. There is no reason why you cannot make your own according to taste.

    Alcoholic strength effects aroma. The trigger point for volatile citric aromas would appear to be around 40%. Dilute to below that strength and you will kill them. 45% abv appears to be ideal for gin. The flavoring ingredients are all natural and are referred to as 'botanicals'. All gins include juniper and coriander. Gordon's also uses ginger, cassia oil and nutmeg. Beefeater uses bitter orange peel, angelica root and seed. Plymouth's 7 botanicals include sweet orange peel, cardamon . Bombay Sapphire uses cubeb berries, cassia bark, grains of paradise, almonds, lemon peel, liquorice, orris root, angelica root. Typically a fine gin contains 6-10 botanicals. The combination of botanicals is important. Angelica root helps to hold in the volatile citric aromas. In most cases the botanicals are steeped in 45% alcohol.This is then redistilled to release the essential oils from the botanicals (less than 5% of the weight - you can therefore work out your yield). Only the middle run at about 80-85% is used.

More essential oil links from Wal ...

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