Craft distilling with The Grainfather
Friday 08 June 2018
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It has collected this stigma through regular and often hilarious references to ‘hillbillies’ and ‘moonshine’. Where the simple method of producing ethanol is perhaps a tad underwhelming, distilling a craft spirit such as whiskey or rum can be just as involved, if not more.
As much as we are all hops heads, who doesn’t enjoy a seriously good whiskey made from malt? We are talking the real deal here; proper high-quality spirits from real ingredients made the traditional way with your very own brewing system like the Grainfather. It’s super satisfying as a home brewer and you’ll be sure to enjoy adding another string to your bow…
Creating a crafted spirit
The simple and very popular way of making alcohol is distilling a dextrose/sugar wash. The sugar wash when distilled (usually using a reflux still) creates plain, neutral alcohol that can then be flavoured at a later stage with commercial alcohol flavourings to give a similar flavour profile to the traditional spirit being imitated – for example, rum flavouring.
However, with craft distilling, we are looking to create a traditional spirit brewed from their traditional source, so barley for whiskey, molasses for rum and grapes for brandy, with many other options as well. Where possible, we would also be looking to handle the spirit after distillation traditionally, for example by aging whiskey on wood, using either barrels or wood chips.
Alcohol can be made by yeast from any simple sugar source. Sugars and syrups like dextrose, brown sugar, molasses and golden syrup are already simple enough that, when diluted, yeast will ferment these into alcohol. Grain products like barley, corn, rye and oats require modification of the starch into fermentable sugars before the yeast can work. The modification occurs by steeping these grains in warm water where the naturally occurring enzymes in these grains convert the starch into fermentable sugars. Other fruits and plants like grapes, potatoes and agave may require other processing before fermentation can occur.
The process of craft distilling for each type of spirit can be somewhat specific to that spirit. But they all can be simplified down to these basic steps:
Prepare the wash - the process of taking the source of sugar (grains, fruits, plants etc.) and processing them so that the sugars are ready and available for fermentation.
Fermentation - adding yeast to the wash to convert the sugar into alcohol.
Distillation - the process of extracting the alcohol from the wash.
Filtration - the process of filtering the alcohol to improve flavour.
Ageing - most spirits require some sort of ageing before the spirit is at its best for drinking.
For example, to make any whiskey from scratch, we will go through the following steps:
Prepare the wash - requires mashing and steeping grains in warm water, so the natural enzymes in the grains convert the starch in the grains to fermentable sugars.
Fermenting – turning the sugars into alcohol
Distilling – distilling the wash to extract alcohol and intensify flavours.
Ageing – age the whiskey in oak, to balance out body and flavours.
Filtration – this may occur at a different stage in the process depending on the distillery.
The yeast used for fermentation in the distillation process is not too dissimilar to beer brewing yeast, and brewing yeast can often be a suitable substitute for distillers yeast. The goal for the yeast in both beer fermentation and distilling fermentation is the same; they both need to produce reasonable quantities of alcohol in a manageable timeframe, settle out of solution and produce low levels of off flavours.
If you do decide to try a specific distiller’s yeast you should be looking for a yeast that uses a heat tolerant Alpha Amylase for converting the complex starch into sugar during the boil stage and also importantly that contain Amyloglucosidase Enzyme, that converts long chain sugars left over from the mash into fermentable glucose.
Many spirits use spices and botanicals to give the spirit unique characteristics that are specific but not limited to that spirit, like juniper berries in gin, cinnamon in cinnamon whiskey and vanilla in spiced rums. Botanical infusions are incorporated into spirits in a couple of different ways:
Vapour infusion: is the process of combining the spirit with the spices and botanicals by using equipment to place the botanicals and spices in contact with the alcoholic vapour as it boils off the wash before the condenser. The botanicals and spices can also be placed in line with the distillation process after the condenser, so the liquid alcohol flows over the botanicals or spices before getting to the collection vessel.
Steeped: Botanicals or spices can be steeped in several ways including in the wash, before the distillation occurs. However, even though the flavour can carry over from the distillation if the spices or botanicals are left in the wash during the distillation, their bitterness or unwanted flavours can also be carried across and the spices and botanicals are boiled during the distillation, which is not always desireable. Botanicals and spices can be steeped during the ageing process before the spirits are bottled, or the botanicals and spices can be steeped in the finished bottle. Both these latter methods are more commonly found in a home brewing circumstance.
Many spirits like whiskey, bourbon and brandy are generally aged with wood that impart both flavours and colour from the wood to the spirit. These woods impart different flavours and colour depending on the type of wood and how the wood is treated before coming in contact with the spirit. The spirit is aged on the wood until the distiller decides the right amount of flavour has been added to the spirit. The speed in which this occurs depends on the climate the spirit is being aged and the way the spirit is being aged, e.g. using barrels (large or small), wood staves, chips or spirals.
As you could imagine, a plethora of wood types exist and, as such, the variety of flavours they can impart is also vast. Here are a few of the more commonly used wood types for whiskey, bourbon and brandies:
American oak: Quercus Alba is the type of white oak most commonly grown in the United States. The forests in Minnesota and Wisconsin are considered particularly good sources of oak. American oak is sweeter and contains more vanillin compounds than other oak species. American oak tends to impart more obvious, stronger and sweeter aromas and flavours. Common descriptors for American oak as well as vanilla are coconut, sweet spices and dill.
French oak: Quercus Petraea and Quercus Robur are the two species of white oak grown in France. Of the two Quercus Petraea is considered the finer. The most important oak forests in France are Allier, Nevers and Tronçais (all in central France), the Vosges in the northeast, and Limousin, which is more westerly near the Cognac region. Of the five, Limousin is the only forest to grow Quercus Robur. French oak (particularly Quercus Petraea) is much tighter grained and less dense than the American Quercus Alba. As such French oak imparts more subtle flavours and firmer, but silkier tannins.
Toasted and Charred oak: These can be either American or French oak that is toasted and or charred using ovens or open flame to draw out particular flavours from the wood.
The distilling lingo
Distillation: is the process of separating one liquid from a mixture of liquids by the combination of boiling the mixture and condensing the mixture. In the case of alcoholic beverages, the process of separating alcohol produced by the fermentation from the wash is done by selectively boiling and condensing the wash under conditions specific to ethanol.
A still: is the equipment used to distil liquid mixtures. Commercial and home stills use the same technology and methodology as a laboratory distillation, but on an adjusted scale to suit the user. Stills are used for producing products like perfume, medicine, purified water and to produce distilled beverages containing ethanol (spirits).
A condenser: is a double walled pipe in which water flows through the outer pipe providing cooling to the alcoholic vapour from the boiling wash, which then condenses into a liquid in the inner pipe and flows into a collection vessel. In the home distilling world, the flow rate of the water passing through the condenser is used to control the temperature, and the temperature controls which alcohol is condensed, which for consumption is ethanol.
Pot/Alembic stills: are the most common type of stills used in craft distilling. By law cognac, Scottish and Irish whiskeys must be produced using a pot still to earn the name (Not only that, but by most accounts they also need to be produced in their place of origin). Pot and alembic stills are common for the production of any spirit where the flavour of the material used to make the wash is desired in the final product like cognac, Scottish and Irish whiskeys that utilise grain or when spices are infused in the spirit during the distillation process like gin and spiced rum. Pot/Alembic stills are characterised by the main boiler unit which boils the wash at the top of the boiler is an arm which has a condenser.
Reflux stills: are very similar to pot stills in that they have a boiler section which is designed to heat the wash in the same way as a pot still. Where they differ is the set up of the top of the still before the condenser. Reflux stills typically have a tall column at the top of the still that contain plates or some item that provides surface area in the column in the commercial side, in the home distilling versions stainless steel saddles provide the surface area. The plates or saddles provide a surface in which the alcohol and water vapour can condense and fall back into the wash. This act is called refluxing and greatly reduces the amounts of flavours that end up in the collection vessel. The result is a very neutral spirit that can then be further processed by adding flavours or re-distilling with botanicals. Because of the reflux action and the resulting neutrality of the spirit, the starting material and fermenting conditions for the wash are less important.
These Stills are typically made of stainless steel, copper or both. Stainless steel is cheap, easy to clean and durable. However copper is a better conductor of heat and will also reduce any undesirable sulphur compounds in the distillate.
Whiskey from Beer on the Grainfather
In home brewing we all have beers that just don’t work out the way we want, or are sitting around in the keg too long and they start to oxidise, but what to do with it? We know we should dump it and start again, but it is difficult to justify with all the time and effort having already gone into each batch, so homebrewers will often pitch some bugs and leave it for a year and see what happens. This has its own problems, but there is also another option, and that is to make some delicious whiskey from your already finished beer.
Distilling beer into whiskey won’t fix egregious falts and produce a great whiskey, but it is perfect for good beer that’s a bit past its prime, and you need the keg, bottles or space in the fridge/ kegerator. Then distilling the beer will give you some more space for beer and as a bonus a bottle or two of whiskey.
Last year we made some Christmas recipes and they were delicious but being summer now in the southern hemisphere it was difficult to drink large amounts of the stout and porter, especially when we had so many good pale ales and lagers on tap here at Grainfather.
So at the beginning of the year, we had about 15 L of the American Toffee Porter left in the keg and thought it was about time to change this out for something else. But it was tasting so good that we didn’t want to dump it and the thought of a toffee whiskey made our mouths water.
The beer had been sitting stationary in the keg for more than six months. Therefore, any remaining yeast had settled out and so no more clarifying agents were added. The beer was transferred from the keg into the Grainfather, it doesn’t matter that it was cold nor that it is carbonated. Five capfuls of spirits distilling conditioner and boil chips were added since beers tend to have a higher protein content than most all grain washes.
The Grainfather with Alembic and collection vessel was set up and water flow set to just over 2.5L per min. The heating was then turned on and set to 65% power. Turn the water on when the thermometer at the top of the Alembic reached 400°C, and all the spirit was collected until the spirit got to 30% ABV.
The American toffee porter was 6.1% ABV and 15 L. Therefore 0.061 x 15 is 0.915L at 100% spirit, but the average spirit out will be about 47%. Therefore, we got about 1.83 L from my spirit run. The grainfather was then left to cool and cleaned out the next morning.
The spirit from the spirit run was diluted to 10 L with distilled water and added back to the empty, cleaned grainfather, boiling chips were re-added. The Alembic and collection vessels were set up and water flow set to just over 2.5 L per min. The heating was then turned on and set to 65% power. Turn the water on when the thermometer at the top of the Alembic reached 400°C. Because beers are fermented cooler, and under more control, the methanol content is much lower than traditional spirit washes so we typically throw away the first 50ml, then collect the heads in 50ml containers. We typically collect 4 or 5 50ml lots of heads before we collect the hearts. When the hearts get around 32% ABV, we start collecting the tails again 4 or 5x 50ml.
After blending the heads, hearts and tails, we had just over a litre of 40% ABV whiskey which we aged on a 3cm charred American oak spiral for a month. The resulting whiskey had a nice golden colour and a good toffee nose which paired well with the charred vanilla and toffee flavours from the charred oak, perfect!
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