Distillation 101: When Beer Becomes Bourbon
There are few places in the world where home distilling is legal. I am lucky to live in one of them right now, New Zealand. I am from the United States where it is a federal crime, a felony, to distill spirits for consumption. I know plenty of people who have home distilled in the United States, but that does not make it any more legal. Keep local laws in mind as you journey ahead!
The art and science of distilling is what separates making beer from making whiskey. You might not realize it, but your beer is halfway to whiskey, the aged spirit of grain. Although numerous spirits can be made from grains like barley and corn, whiskey is the most recognized spirit that comes out of the still when you distill your beer, often referred to as a wash when it is coming out of the fermenter for distilling.
As a homebrewer, the addition of a still can add a bit of fun to the hobby of homebrewing. Let us look at what steps are needed to make whiskey, and more specifically Bourbon, the native whiskey of the United States, and get a general understanding of the process. Although this may not include everything you need to feel comfortable to start, I hope it gives you an idea of the process and what might be involved should you want to continue learning and make the leap into distilling.
The Distilling Process
Step 1: Mashing
If you’re already a homebrewer, you know the mashing process is used on grains, which are sometimes referred to as cereals, to provide the brewer (or distiller) with simple sugars that can be eaten by yeast. Many different spirits can be made using grain, including whiskey. However, if you’re drinking something like vodka or gin, it probably is made from plant-based, naturally occurring sugars, like those found in sugar beets and sugar cane, as this is the cheapest route. These sugars don’t need to be mashed, saving you the time and energy of the mashing step.
The equipment you will need for mashing, which most homebrewers likely already have, includes:
• Long stainless steel spoon or mash paddle
• Pitcher for pouring water over grains for sparging
• Mash tun, at least 5 gallons (19 L)
• Sparge water heater (also known as a hot liquor tank)
• High-temperature silicone tubing
• Grain mill (optional)
• Heat source for heating your mash and sparge water
• Water source for mashing and sparging grain
Cereal Mashing (sidebar)
Cereal mashing would be done before saccharification — the standard mashing process of converting starch into sugar. It’s best to understand single-step, single-temperature saccharification mashing first. This can be performed as you would an all-grain beer, generally for distilling holding crushed malted grains in water between 145–150 ˚F (63–66 ˚C) for an hour. But, for many distillers who want to make grain-based spirit from raw, unmalted grains, as you often do to make Bourbon, an understanding of cereal mashing is needed.
Cereal mashing is a great technique to learn. It allows you access to any type of grain for distilling. Raw grain is often cheaper and sometimes more accessible than malted grain. Still a preferred method for some distillers, cereal mashing has been employed for a long time in distilling. It can be used to produce several spirits — Bourbon, corn whiskey, rye whiskey, gin, and vodka.
The process of cereal mashing can be a bit loose and varied, which also allows you to be less precise. So, if you understand the steps it takes, and follow trusted recipes at first, you’ll get excellent results from cereal mashing unmalted grain.
Gelatinization
Gelatinization is an important first step in cereal mashing to make the starch in raw grain readily available to enzymes. Oftentimes distillers refer to “cooking” their grains, and technically what they’re doing is gelatinizing their grains. First, break or “crack” your grain through grinding or milling. Although difficult with raw grain that is quite hard or fresh grain with high moisture content, breaking your grain will make the process much quicker and easier, and may be required to access the starch inside some grains.
Adding enough water to cover the grain is the next step. The exact amount of water during gelatinization isn’t so important. In my home kettle, I put about an inch (2.5 cm) of water above my grains. If you’re looking for repeatability be sure to measure. Between 0.9–1.3 qts./L of water per pound (0.45 kg) of raw grain can be used as general guidance. As the heat rises in the kettle and the grains absorb water and swell, you may be left with a sticky mush that’s hard to stir if there isn’t enough water. It may thicken to the point that it scorches on the heat source. Always stir and add more water as you go, if needed.
Slowly bring up the temperature until gelatinization occurs, which is different for every grain. I recommend bringing your grains to a boil and then letting them cool as it speeds up the gelatinization process. Some grains such as wheat and rye don’t actually need the high temperatures to gelatinize. Your porridge of water and grain should get gooey and thicken as the starch begins to break down. It thickens because the starch has been released into the water. As you stir, the porridge should start to cling to your mixing spoon but slide off, like runny yogurt, often leaving a starchy layer on the spoon. Now that you’ve achieved getting the starch out of hiding, you’re ready for the next cereal mashing step: Liquefaction.
Liquefaction
Liquefaction is literally the process of liquefying your starch. Liquefaction begins to break the starch down through alpha-amylase enzyme activity. Alpha-amylase is an expert cutter of long-chain starch molecules into smaller, more manageable sugars and dextrins. The alpha-amylase enzyme comes in different formats from different natural sources: Plants, bacteria, and fungi. Most are dried and powdered. All work well, but the most sought after are alpha-amylase that can work at high temperatures. These can be added during the gelatinization stage, and bringing your grains to a boil doesn’t deactivate these enzymes. Lower-temperature alpha-amylase enzyme can also be used for saccharification. Notice it likes a lower pH, which can be good if you’re trying to break down fruit. Medium temperature alpha-amylase enzymes are quite common and very general-purpose, often recommended for grains in the lower gelatinization temperature range, as it can liquefy as you gelatinize. High-temperature alpha-amylase is great for those grains that need a bit more heat to gelatinize.
You’ll know when liquefaction has occurred when the stirring gets easier. A well-liquefied cereal mash will be easy to turn into simple sugar. Be patient: This process can take 20 to 30 minutes, or even up to two hours, so give it some time. Pro tip: Alpha-amylase is rather inexpensive and adding more will shorten the time.
Saccharification
Saccharification is typically a single-temperature mashing step used to convert starch to sugars. The goal is to take your mixture of hydrolyzed starch, now in the form of dextrins from liquefaction, and make it into absorbable yeast food. Remember, without converting dextrins down
further to simple sugars, the yeast can’t create the ethanol we hope to collect and enjoy at the end of the distilling process.
At this point in cereal mashing, depending on your recipe, malted grain may be added for both its own starch and enzymes, and a standard saccharification mash at between 145–150 °F (63–66 °C) could be completed. Malted grain high in diastatic power (high in amylase enzymes) is needed to convert all the long-chain sugars in your cereal mash. This malted grain may just be called base malt, two-row malt, six-row malt, and, if it’s really high in enzymatic activity, distiller’s malt. A good rule is to add at least 30 percent or more malted barley to have ample enzyme activity able to convert dextrins to simple sugars. Not adding more grains? Another way to saccharify your mash is to add exogenous enzyme. There are numerous choices, with some working best at lower temperatures, often around
140 °F (60 °C) or less.
Glucoamylase (amyloglucosidase) enzyme is the most recommended enzyme for this last step in the cereal mashing process. It’s extremely efficient and works in mashes that may be somewhat acidic. Beta-amylase is the common enzyme in barley and can also be found on the shelf in fungal form ready to be added to your mash. Depending on the number of enzymes, active saccharification can take anywhere between 20 to 90 minutes when using raw grain. As mentioned before, look to hold saccharification temperatures for about an hour, after which your starches should be fully converted to sugars. To finish mashing rinse your grain with hot water. From here you’ll either boil to condense your wort or cool the wort down immediately for fermentation.
Step 2: Fermenting
Turning sugar into alcohol is a critical step in the distilling process. While you can purchase beer, wine, or cider with the intent to distill it, these beverages were not made for distilling, so your results may vary. When you ferment your own alcohol, you have more control over the outcome. You will choose a yeast that is quite efficient at absorbing sugar and creating alcohol as a by-product. At times, you may choose a yeast to provide and emphasize flavors particular from the sugary mash product, while other times you may select a yeast to produce a clean, neutral flavor. Thus, by fermenting you are in the driver’s seat during the creation of alcohol and the initial flavor development.
The basic equipment you need for fermenting your wash includes:
• Fermenter (at least 6 gallons, or 23 liters) with a lid or stopper
• Airlock
• Specific gravity hydrometer
• Racking cane with plastic tubing or auto-siphon with plastic tubing
Step 3: Distilling
The distilling process itself is that one step unique to making spirits (as opposed to making beer), in that you are separating and then concentrating the alcohol. That’s the basis of distillation — separate the alcohol from the water as vapor in the boiler of your still, and then recondense it into liquid in the condenser of the still for collection. Beer usually isn’t over 15 percent alcohol by volume (ABV) for a reason: It hasn’t been distilled. Most spirits are around 40 percent ABV, though sweetened aperitifs and liqueurs are often less. Let’s assume you will use a still to do this, though there are other methods such as freeze distillation. Still types are covered in more depth in my book How to Distill, but you’ve probably seen one online, at a homebrew shop, or maybe on a distillery tour. It has:
• A boiler
• A closed dome or column on the top for some amount of refluxing (re-condensing of vapor inside the still)
• A condenser arm or tube that cools the vapor back to liquid form
• The use of a still to perform distillation to concentrate alcohol is the biggest difference between making spirits and making beer.
• The equipment you will need for distilling includes the following:
• Still (a pot still is preferred for whiskey)
• Proof and tralle hydrometer for measuring alcohol of spirit
• 12 to 15 collection jars (16 oz. or 500 mL) for making cuts
• Distiller’s parrot or 8 oz./250 mL glass test jar (cylinder) for measuring your spirit proof
• Water source for condenser arm of still
• Heat source for still boiler
• Boil enhancers/chips (optional, for a more even boil)
If you’re unsure about how or what from your cuts jars to blend, when doing a single distillation run it’s a good idea to be more cautious and put less in from your heads and tails (roughly the top third and bottom third, respectively) than you’d estimate. A safe volume is 60% (though you could do less if you’re not happy with the flavor of the jars) of what you collected, working from your middle jar. So, if you collected 10 jars, your six middle jars could be blended to form your whiskey for aging or drinking.
Step 4: Polishing
If you are looking for a nice, clean, and neutral-flavored spirit post-distillation then polishing is the answer. This filtration step can improve your spirit by taking out impurities created mostly during fermentation. If you are aging your spirit on oak, a small amount of these flavors can be good so polishing might not be warranted! If not, they can leave a nasty off-flavor and aroma in your clear spirit. If you are careful how you collect your alcohol, leaving the heads and tails separate, you can blend these in post-distillation in smaller quantities that cut down on the harsh flavors, and maybe add some character to your spirit. Or, if you are making a whiskey that is going to be aged a long time, a polishing step can be less critical and likely not even necessary.
The equipment you will need for polishing (optional) includes:
• Activated carbon
• Carbon filter to hold the activated carbon
• Collection vessel for polished spirit
Step 4: Aging
Aged or matured spirits are usually easy to identify. The yellow, amber, or brown color you see in spirits like whiskeys, rums, brandies, and tequilas comes from the aging process, usually from contact and time with toasted or charred oak or another type of wood. The burnt parts of the wood begin to color the spirit almost immediately and new bold and beautiful flavors like vanilla, caramel, and tobacco will develop in the spirit over time. At home, this can be done with charred oak chips, staves, or spirals in a glass jug or jar, or by putting your spirit directly in a small toasted or charred wooden barrel.
The equipment you will need for aging whiskey (like Bourbon) includes:
• Toasted or charred oak barrel (minimum 2 gallons or 6 to 8 liters) or oak chips, staves, or cubes
• Muslin cloth (or coffee filters)
• Glass aging vessel (if not using a barrel)
• Glass or stainless steel barrel thief or wine thief (for taking samples if using a barrel)
• Stainless steel racking cane and silicone tubing (for transfer if using a barrel)
Step 5: Blending and Bottling
There are numerous things you can still do after distilling, polishing, and/or aging to improve your spirits. The first that comes to mind is blending. Part art, part science, the title of master blender is a position at many large whiskey distilleries that takes years of apprenticeship and experimentation, learning the common flavors and off-flavors associated with distilling and aging — and really understanding your own palate. Honing your own sensory skills can be valuable to blending your own spirits. Obviously, to blend spirit, you’ll need more than one around. This can be created from a single run by aging spirit on different types of charred or toasted wood, and at different ABVs. Multiple runs of whiskeys that are at different point in the aging process, or may be slightly different, will work well for blending.
Packaging your spirit in a properly corked, waxed, and labelled bottle may not be seen as critical by all in the hobby distilling community, but it is a nice touch. True, maybe you will decide your collection jug is the best final package for your spirit. However, the classic way to finish most spirits is a clear glass bottle (500 or 750 mL being common sizes), as a clear bottle offers a good look at the spirit itself.
The equipment you will need for blending and bottling include:
• Glass or stainless wine thief
• Assorted small glass test jars or beakers
• Notepad
• Tasting glass
• 100 to 250 mL graduated glass test jar for blending
• Spirit bottles of your choice
• Glass or stainless pitcher or auto-siphon with silicone tubing (optional)
• Spirit bottle corks or caps
• Bottling wax and tin can for melting the wax (optional)
• Labels
Now that you’ve read a general overview of the process you might be quite interested in moving ahead with learning more and purchasing a still. A pot still will be a great way to go if you’re interested in whiskey, and more specifically Bourbon whiskey, though other styles of still can work. A column still, which is quite easy to identify by its taller cylindrical column coming straight up off the boiler, offers more reflux than a pot still. Reflux is the process by which vapor rises in the still and recondenses inside the still falling back toward the boiler to be revaporized. This creates a higher proof alcohol from the still, but also strips the spirit of flavor. A pot still offers less reflux, which in turn means more flavor in your Bourbon. A simple way to begin is by investing in a small stovetop still, or by purchasing something like the Still Spirits Air Still. Most stovetop stills are a “pot still” as is the Air Still. If you brew beer using an electric brewing system (like those featured on pages 46–59 of this issue), consider seeing if still attachments are available. Some will allow you to mash grain and then pot distill with excellent control.
If you are unfamiliar with much of the distilling equipment mentioned, start researching. If you haven’t yet purchased a still or are interested in digging deeper into the process, be sure to check out the book How to Distill from which the prior text and the following recipe are excerpted.
Bourbon-Style Whiskey Recipe
The difficulty in making Bourbon is mashing unmalted grain such as corn. Because it doesn’t need a cereal mash, pregelatinized corn flakes are a great place to start, but it requires care and attention to the mashing process and effective use of enzymes to be the most useful as a provider of sugar to your wash. Rye malt is easier to manage than rye flakes in your mash, as rye flakes like to completely gelatinize, resulting in a “stuck sparge.” The rice hulls are in the recipe to help alleviate this potential headache. If you’d like to use raw corn or rye in place of the recommendation in the recipe, be sure to cereal mash, as described earlier in the sidebar. This recipe will make about 5 gallons (19 L) of wash:
OG: 1.096–1.104 FG: 1.000–1.010
ABV: 12–13%
YOU WILL NEED:
• 10 lbs. (4.5 kg) Briess Brewers Yellow Corn Flakes
• 6 lbs. (2.7 kg) Rahr High DP Distiller’s Malt
• 2 lbs. (0.9 kg) Gambrinus Rye Malt
• 12 oz. (340 g) rice hulls (optional)
• 12 g Still Spirits Distiller’s Glucoamylase Enzyme
• 20 g Still Spirits Whiskey Distiller’s Yeast
• 2-gallon (6- to 8-L) medium toast or charred oak barrel, new or used for Bourbon (or 100 g medium toast oak chips)
STEP BY STEP
1. Add 6 gallons (23 L) of water to your mash tun and heat to 162 °F (72 °C).
2. Stir in all grains (and optional hulls) and hold the temperature at 148 °F (64 °C) for 60 minutes.
3. Let the temperature fall in the mash tun to 139 °F (59 °C). Stir 12 g glucoamylase into the mash.
4. Keep the mash between 123–139 °F (51–59 °C) for one hour.
5. Heat 2.2 gallons (8 L) of sparge water to 180 °F (82 °C) and sparge grain. Optional: You may choose to bring the wort to a boil to ensure it is free from bacteria prior to fermentation and to condense it down (15 minutes is ample time to ensure a sterile wort, and up to an hour should be ample to condense wort to less than 5 gallons/19 L, should space in your fermenter or still be an issue). Neither is required if your equipment is clean and your fermenter is at least 6 gallons (23 L), large enough to manage around 5.25 gallons (20 L)
of wort.
6. Cool the collected wort and add to your fermenter.
7. Pitch yeast once the temperature is below 95 °F (35 °C).
8. Ferment at 72 °F (22 °C) for 14 days. Transfer the wash to your still.
9. Distill using a single run in a pot still or unpacked column still, or with three or fewer plates in a flute still. Discard the first 50 mLs out of your still. This is the foreshots and can contain methanol. Collect in bulk until your average collected spirit is 35 percent ABV (70 proof.)
10.Take 14 even cuts across your run (four 500 mL heads jars, six 500 mL hearts jars, four 500 mL tails jars).
11. Taste the heads, hearts, and tails to get familiar with their flavors.
12. Take just your hearts, and possibly some small portions of your heads and tails; no more than 12 oz. (355 mL) of either is recommended for your first Bourbon batch. Try to aim for a collected spirit between 50 and 62 percent ABV (100 and 124 proof) for aging. Add clean water if your collected spirit is higher.
13. Add it to a barrel or age on oak chips. A barrel allows for evaporation and oxygenation of the spirit, which helps develop flavor. This can be mimicked in a glass jar by leaving the lid slightly loosened for a few weeks, just be careful not to tip it over!
14. Age for a minimum of six months and, if possible, up to two years to make it “straight” Bourbon.
This article contains excerpts and images from the book How to Distill by Aaron Hyde, printed by Harvard Common Press and releasing November 2, 2021.
