How we make spirits

So, how do we make spirits of exceptional quality and character at the Copper House Distillery?

We believe great products from quality producers must demonstrate authenticity and provenance if they are to win the support of a loyal customer following.

Whether it’s one of our award winning beers or a top quality spirit, we have taken every care to select the best ingredients combining these with high quality processing and a wealth of ingenuity and innovation of our brewing and distillery team.  We also add a liberal seasoning of sustainability and carbon reduction measures – but more of them later.

All our spirits are based on locally grown, East Anglian malted cereals, with which we brew a “distillery wash” – a 7% abv beer, unhopped – using our unique two strain brewing yeast, that has been in use for over 70 years.

The make up of the grist, the malt blend, is a first corner stone to the individuality and character of the final spirit.

For example, Adnams Barley Vodka has a 100% malted barley grist – drawn from the finest locally grown – whereas Longshore “Finest Cut” Vodka has a three grain grist of malted wheat, barley & oats, giving a more complex yet smooth finish to the spirit.

Having milled the grist and mashed it in our normal manner, we ferment the unhopped wort with Adnams yeast for seven days.  After which, all the available sugars extracted from the cereal malt grist have turned to alcohol.  This results in a distillery wash of approx 7% abv, ready to gently pump to the ‘wash holding tank’ in the Copper House Still Room.

The skills of the Master Brewer in creating unique distillery washes, now gives way to the skills of the Distiller to work his magic in turning weak wash to a pure final strength spirit.

A good, well-controlled fermentation enables us to produce a higher quality wash with very low levels of methanol.  It is ethanol that forms the basis of the spirits we drink – thus limiting the amount of methanol produced at the fermentation stage is a good start to producing a quality vodka or gin.

It is the brewery fermentation process that creates our base alcohols. During the distillation process we seek to concentrate and separate these various alcohols and fusel oils to make a quality drinking spirit.

Now lets take a look how we turn a 7% beer wash into quality handcrafted spirits.
The Stripping Run

The first distillation process is designed to remove all the alcohols from the bulk of the fermented beer or wash.

In 250hl of 7% abv wash we have created approx 17.5hl or 1750 litres of OH (100% alcohol by volume).

As this is a large amount of fluid to distil for a relatively small volume of alcohol, we need a large capacity Still specifically designed for the task.

We use a Carl 10hl per hour “Beer Stripping Still” as common to the American Bourbon Distilleries to achieve this first distillation run and this produces high quality “Low Wines” at approx. 85-90% abv.  ‘Low Wines’ is the name given to the cocktail of alcohols and fusel oils that come out of the stripping run.

It is possible to do this stripping run with a pot still but it takes five times as long  and will use 40% more energy, producing a lesser quality Low Wines output of around  55%-60% abv.

The Low Wines are then diluted and stored ready for the next part of the process and this next distillation will vary, depending on the type of spirit we wish to produce.

For now, let’s think vodka – for if we understand the rectification distillation process to achieve vodka quality spirit, all else will become clearer.

Rectification – 1st Rectification – 2nd Rectification and Final Polish

We now have in our low wines tank a cocktail of alcohols, fusel oils and other compounds ready for further processing.

We now need to achieve further purification of the spirit by separating fractions called the Heads, Hearts and Tails contained in the Low Wines. We will then  continue to process the “Hearts” fraction ethanol into our final vodka spirit.

Fortunately, most alcohols have vapour points below that of water.  It is this fact that enables us to separate a mixture of alcohols, water, proteins and carbohydrates in a “beer wash” and, by gentle boiling, evaporating off and re-condensing elsewhere the various alcohols as Heads, Hearts or Tails.

Imagine we could stack in the “Low Wines”, alcohols and fusel oils in a vertical column as our Diagram 1, and then draw off the alcohols from the top of the column in order of volatility, we would be able to separate the fractions into Heads, Hearts and Tails into separate containers as we dictate.

This, in a simplistic sense, is just what occurs during the rectification process.

Having filled our handmade Copper Pot Still with Low Wines, we apply heat and allow the vapours to enter the Rectifying column.

Think of our Rectifying still as a single 16m high column with a series of 42 plates or steps, equally spaced from top to bottom.

The hot alcohol vapours enter the bottom of the column and rise up towards the top where they meet a condenser unit, cool and run back down the column as liquid.  This is called reflux.

For a moment let’s consider the action around a single plate or step.

As heat is applied to the Copper Pot Still, at around boiling point a mixture of alcohol vapours proceeds into the rectifying column.

Warm vapours rise and meet plate 1, proceeding through the bubble cap holes, vapours of lower volatility will condense on top of the plate and form a liquid whilst the more volatile alcohol vapours proceed to the second plate.  Again, some vapours condense on top of the plate, excess fluid runs back down the column to the pot and some more volatile alcohols proceed up to plate 3.

The bottom of the column is fed with hot alcohol vapours, while the condenser unit at the top of the column is fed with cold water – the 42 plates in between slightly decreasing in temperature at each step up the column.

Remember we are interested in separating alcohols into precise fractions of Heads, Hearts and Tails – hence the more plates or steps of separation available to us in the column, the better and clearer we can identify and carry out the separation.

Chemical        Boiling Point

Acetaldehyde        20.8
Acetone        56.2
Methanol        64.7
Ethanol        78.2
1-Propanol        97.0
Water             100.0
Isopentanol        132.0

Having run the Pot Still and Column as a closed reiterative process for say two hours (not allowing any alcohol to leave the still) we have nicely stacked up and separated alcohols in the rectification column per diagram 1.  We can then slowly draw off from the top of the column first the Heads, followed by the Hearts, and finally the Tails fraction.

One of the skills of a Distiller is to be able to judge the right moment to “cut” the still outflow from Heads to Hearts and Hearts to Tails – allow different permutations depending on the final spirit being produced.

At the Copper House Distillery for our vodka and gin, we allow a generous amount of ethanol to run to the Heads tanks before “cutting” to the Hearts. Similarly as the run approaches the Tails, we cut it well before the appearance of any heavy alcohols or fusel oils.

The greater the sacrifice of ethanol from the margins with Heads and Tails, the greater purity and no further treatment with carbon filters before bottling.

A full rectification distillation run takes some 12 hours at the end of which we have a small amount of Heads, the Hearts (Vodka) and a tank of Tails.

Having completed the first rectification run, we now dilute the ethanol alcohol in the Hearts tank to 50% abv with water.  We return this to the Pot Still and carry out a 2nd rectification, refining the ethanol still further.  The Hearts from this 2nd rectification process then pass through our vodka polishing column, which further refines the spirit to exceed the highest EU standards of vodka production.

Copper Stills help produce cleaner, smoother spirits by removing sulphates, which attach themselves to the internal copper surfaces during the distillation process.  After a few distillations we have to clean the Stills thoroughly to remove these sulphates and keep clean copper for the next run.

Large scale ethanol plants are made as a series of stainless steel continuous processing columns – lacking the properties of copper to remove sulphates as Copper Stills.  Often much talk of the final filtration through carbon or other elements is the marketers storyline for these mass produced Vodkas.  We believe that high quality batch distilled vodka should require very little further processing before bottling .

Finishing the Vodka, Bottling & Packing

Having double-rectified the spirit, we store the vodka spirit at 55% abv having diluted with pure water.

Some 800 ltrs will be drawn off to a small tank adjusted to correct abv % by weight.  By chilling the spirit to -2°C and then passing through a fine paper filter, we remove any particles and long chain protein molecules that would otherwise precipitate out when the vodka bottle is in your fridge or freezer – turning your vodka cloudy at low temperatures.

We do not use carbon or other compound filters – well-controlled fermentations & great distilling in Copper Stills allow us to give you an authentic product.  The spirit is then warmed to 20°C and is ready to bottle.

Our bottling and packing are done by hand.  We flush clean our bottles with a little vodka before filling on a four head vacuum filling machine which ensures a correct fill every time.

Hand-corked and sleeved with a tin capsule, the labels are applied front and back with a small hand-operated machine.

Now we have handcrafted, premium vodka ready for dispatch to our Cellar & Kitchen Stores, hotels, pubs & restaurant customers and of course, through our online shop.

From great vodka we make great Distilled Gin

Distilled Gin, according to EU regulations, is a spirit derived from vodka quality spirit, infused with botanicals of which juniper must be the predominant flavour.

We use the method of Distilled Gin production to make a vodka quality spirit. Using our Copper Pot Still and Copper rectifying column, we subsequently redistill the Vodka in our Pot Still with an infusion of selected botanicals.

We charge the Copper Pot Still with Vodka quality spirit at 50% abv late afternoon, warm up to some 50°C and place up to 13 selected botanicals into the warm spirit to soak overnight.

As we have charged the Still with our purest vodka, we have no need to reuse the rectifying column.  So this time, a simple distillation using only our Pot Still will over 6 hours bring off the spirit and botanical oils flavours.

We only recover 95% of the vodka spirit in this gin run, again ensuring a gin of superior quality, character and smoothness.

This gin is then chilled and filtered, hand-bottled and packed following the same process as our vodka.

The Botanical Recipes for Adnams Distilled Gin & “Finest Cut” First Rate Gin

For several months our Distiller John McCarthy experimented in our brewing laboratory to formulate 30 different gin recipes using a wide array of botanicals.

Through a process of blind tasting panels and preference feedback, he finally honed the recipes for Adnams Distilled Gin and “Finest Cut” First Rate Gin.

Adnams Distilled Gin botanicals consist of:
Juniper Berries
Orris Root
Coriander Seed
Cardamom Pod
Hibiscus Flower
Sweet orange Peel

“Finest Cut” First Rate Gin botanicals consist of:
All of the above (with the exception of hibiscus flowers) plus:
Lemon Peel
Cassia Bark
Vanilla Pod
Angelica Root
Caraway Seed
Fennel Seed
Thyme
Liquorice Root