Why You Need Copper in Your Distillery (Copper vs. Stainless Steel)

Why you need copper in your distillery (Copper vs. Stainless Steel) is a simple question to answer. While it may look a little old-fashioned, copper is a necessary and integral part of the distilling process.

To understand why that is, let’s look at the process of making alcohol.

It uses evaporation and condensation to distill a mixture of liquids with different boiling points.

Stainless steel and aluminum stills are popular. But copper is the preferred construction material.

This is in part due to its pedigree stretching back more than 2000 years. The ancients understood that copper helped impart flavor to distilled spirits.

How it does this is a bit of a mystery.

Copper’s anti-microbial properties and excellent ability to conduct heat are well-proven. And, its ability to remove volatile sulfur compounds is well known.

This all plays a role in its mythical transformation of humble ingredients into a delicious tipple.

Copper vs. Stainless Steel

When compared to copper, stainless steel has lower heat transfer qualities. Stills made from stainless steel are more difficult to control as well as adjust during distillation.

Heat input adjustments or cooling water adjustments take a while to take effect in stainless components. Whereas, with copper, the effects occur almost immediately.

Those in the know will tell you that copper is a better material for distilling spirits. This is due to the metal removing sulfides from the distillate. It also produces a better tasting and smelling final product.

The best features of stainless steel are that it is less expensive than copper, it is very durable and easy to clean.

If you’ve spent time in a distillery you’ll know the back-breaking amount of work it takes to keep all the equipment clean. Reducing the amount of time it takes to clean plays a major part in buying decisions.

The main negatives to stainless steel distillers are that they are not the best conductor of heat. They also don’t remove sulfur compounds from the wash.

There is, however, more to consider than just the material properties.

Each one is slightly more appropriate for completing certain tasks. In other words, copper stills may be better at doing some things while stainless steel stills are better at doing others.

When deciding on a stainless-steel distiller or a copper distiller, you need to consider these three questions;

1. What is being distilled?
2. What types of features do you need?
3. And are you going to use a pre-built distiller or a DIY still kit?

Ask any whiskey maker, especially the ones you find deep in the woods. They’ll tell you that copper is a vital component when distilling spirits.

But, your still doesn’t need an all-copper construction to get the sulfur-eliminating benefits. You can choose a stainless-steel still and use copper in your vapor path.

The debate on how long the vapor path needs to be is ongoing. You may get through a bottle or two of your product and still not reach a conclusion, depending on whom you’re chatting to.

Why Do You Need Copper in A Still?

During the distilling process, sulfur emanating from the yeast binds to the copper. The sulfur pathways followed by yeast produce hydrogen sulfide (H2S), which then forms copper sulfate.

For this reason, it’s important to have clean copper inside the still so that the sulfur has plenty of surface area with which to make contact.

Research into the yeast, Saccharomyces cerevisiae, has revealed low levels of H2S. The low levels have a positive effect on the quality of beverages.

The complex chemical reactions with copper remove the highly volatile sulfur compounds. The main one is dimethyl trisulphide or DMTS. DMTS’s aroma is best described as being close to rotten vegetables (which you really don’t want in your distilled spirit).

There is also an argument that copper helps in the formation of esters. These give spirits a fruity character. Others believe that by removing the sulfides, copper merely helps the esters become more apparent.

Whichever view you take, the copper sulfate adheres to the inside of the still during the distillation process. And, once you’ve given the copper still a thorough clean, the copper sulfate washes off into the drain. It then doesn’t have a chance to contaminate your alcohol.

This, unfortunately, doesn’t happen with non-copper stills and your end product includes those sulfates. There is a way to combat this and we’ll cover that in a moment.

How to Clean Copper and Stainless-Steel Stills

Cleaning both copper and stainless stills follow similar processes.

Professional distillers will clean their equipment with a more specialized acid cleaner. Home distillers, however, can use the following process to get acceptable results.

Stainless-Steel Stills

When you first receive your still, there are residues inside, left over from the manufacturing process. You’ll want to remove those.

There’s no need for fancy cleaners, ordinary dishwashing soap is perfect for the job. Add some dish soap to the warm water and give the still a good rinse. Use a soft cloth to give all the surfaces a good rub.

To clean the pipes, use a 2-inch brush (toilet brushes work great) on the bigger pipes and make up a pull-through for the smaller diameter pipes.

If you’ve ever cleaned a rifle or shotgun, you’ll know what I mean. Tie a little copper mesh to the end of a piece of stiff wire, then feed it through the pipes and pull it out the other end. You’ll want a bit of the hot, soapy water in there first.

Do it a couple of times and your still will be thoroughly clean.

Cleaning Copper Stills

Follow the same procedure as detailed for stainless-steel still above. Then proceed with an acid wash.

Half-fill the still with your vinegar solution. You want a 50:50 water to vinegar mix.

Heat the still and let it run as though you were making alcohol. The acid will clean out the still and also give you a chance to check that there are no leaks in the system.

Once the vinegar mixture has run through the condenser, take the still apart and rinse everything off with water.

The next step is steam cleaning. You’ll find the cleaning sequence is up for debate. But cleaning the still after running the vinegar mix helps remove any residue that may impart unwanted flavors to your product.

Fill your still half full of water and allow the steam to build up and flow through the system. Keep the cold condenser water closed to allow the pressure to build up and run through the pipes. This removes any remaining contaminants. After about 5 minutes, open the cold-water valve and allow the condenser to cool the steam so that you get water coming out, flushing the pipes.

Be careful that you don’t run your boiler dry as that will damage it. So, collect about half the volume of water that you placed in the boiler, then stop and let it cool down.

A Citric Acid Bath

Next, you need to clean out the sulfites from the boiler and the vapor path.

You do this by using hot water (hot tap water is fine) and citric acid. Pour 50 to 100 grams of citric acid into a few liters of hot water and stir it up so that the citric acid dissolves.

Once the acid has dissolved, disassemble your still and dunk the boiler, vapor chamber, and condenser into the solution. Make sure that the solution makes contact with all the internal and external parts of the equipment.

The acid will react with the dark-colored sulfides, removing them and leaving the surface clean and shiny. When you take the copper out it will have a bright pinkish tint. This color turns to the traditional golden color once the still warms up.

You want the internal surfaces as clean as possible. This is so that the steam and vapors make full contact with the copper. It then ensures that your liquor is free of sulfides.

You want to leave the still in the acid solution for 5-10 minutes so that it has plenty of time to do its work.

You’ll notice that the water and acid solution turn a blueish color. This is due to the sulfides remaining behind.

Passivation

The last part of the process is to passivate the copper.

After removing the still from the acid bath, there is an acid residue that remains on the copper surfaces. If you leave it, when you next use your still, you’ll get a blue distillate instead of a nice clear liquid.

The blue color indicates that there is acid contamination. Now, this may not be such a big issue as you’ll remove most, if not all, of the contamination in your heads. But it may still affect the flavor of your run. So, if possible, you want to avoid this and do it by passivating the still.

You use a weak potassium carbonate solution to remove the remaining acid. A quick rinse neutralizes the acid.

Just remember that a blue distillate is not necessarily due to acid residue. It may also be the result of excess nutrients in your fermentation.

What Components Should Be Copper?

Distillation equipment manufacturers typically use stainless steel as it is cheaper than copper.

The materials used in industrial distillation find their way into micro-brewery equipment.

While traditional stills use copper, modern stills use a combination that makes financial sense. To this end, manufacturers include copper mesh inside the stainless-steel column.

This allows the vapor to contact the copper and offload its sulfides while at the same time reducing the cost of the equipment.

While there are additional pieces of equipment that you can add to the still, the apparatus consists of two major parts:

• The boiler, also known as the distillation flask (or pot), heats the mixture and volatilizes the components.
• A column or condenser to cool the vapors back to a liquid state.

Here’s what each component does and its characteristics:

Boiler:

• Primarily used for distillation.
• Preferably a rounded bottom rather than flat.
• Never fill it more than halfway with the liquid mixture.
• Avoid over-filling the flask, as the bubbles will foam up in the narrow part of the flask and possibly overflow.
• Older ones are copper while modern ones are stainless steel.

Column:

• It connects to a source of running water to provide cooling for the vapors.
• You should connect the input hose to the furthest end of the condenser away from the heated flask. The outflow should be closest to the heated flask
• This will prevent the hottest vapors from contacting the coldest water and creating a large thermal shock to the glassware.
• The hoses must connect tightly enough to the condenser so that it does not come loose if the water pressure were to increase.
• This means that copper wire is usually twisted around the tubing at the joint to prevent it from coming away.
• The flow of water needs to be sufficient to accomplish condensation without being so fast as to cause undue hose pressure.
• Remember that flow rates can change during the day after they have initially been set.
• It is traditionally made of copper but modern designs are usually stainless-steel with copper mesh inside.

Still manufacturers introduce copper mesh into the stainless-steel column. This allows the vapor to offload its sulfides onto the copper before condensing.

Copper vs. stainless steel for vodka/neutral making

Copper is great for high-proof spirits like vodka. However, vodka is best distilled in vessels with a reflux column as it’s quicker that way.

This does not mean that stainless stills are suitable for distilling spirits.

The purpose of copper, when used in distilling, is to catalyze reactions that remove notes or flavors in the distillate which are not wanted. It also produces a smoother result. The distillate ends up with an unpleasant smell and taste without copper.

However, the still will work even if it is not made of copper. It’s a question of whether you are willing to forgo the quality benefits of using copper.

Copper vs. stainless steel for whiskey

Copper has the advantage over stainless steel. But neither stainless steel nor copper will put any harmful chemicals into your final product.

Copper just makes your whiskey taste better.

The copper reacts with the various sulfur compounds at a molecular level. The sulfur taste is then removed so that there is no bitter after-taste.

Pot stills are generally recommended for making whiskey.

They produce a more full-flavored spirit. A higher purity, with a less distinctive-tasting liquor, is the end result.

To achieve this, you must run the distillate through the pot still twice rather than just once.

Copper vs. stainless steel for rum making

Pot stills are the best option for making rum. These are the original rum stills that are still used today to create weighty and characterful spirits.

Flavors will differ between distilleries and with a pot still, you get heaps of character. Rums made in a pot still are excellent sipping rums. They create punchy mixtures that will shine through any pairing.

The stills are traditionally constructed from copper and come in a range of shapes and sizes.

You can make rum either using a stainless-steel pot with a copper column or a 100% stainless steel column packed with copper mesh.

Both are fantastic options for producing spirits.

Copper vs stainless steel for gin making

It isn’t necessary to distill your own alcohol when making gin and, for this reason, you do not necessarily need copper to remove the sulfides.

However, purists insist that you produce gin from your own vodka. For this, they use a reflux still and you need the copper to remove the sulfide. The choice, as always, is yours when it comes to which method you prefer.

The best gins come from pot stills. And, as with so much in the distilling world, opinions vary on whether your herbs should contact alcohol directly or whether the vapors should only be in contact.

Bold gins require direct contact with alcohol. If the flavors are too strong, then dilution with additional vodka is an option.

Copper vs. Stainless Steel Stills

Copper stills have all the charm of traditional distilling. While stainless steel stills convey the benefits of easy cleaning.

Let’s look at some of the characteristics that you should consider when deciding on which style suits you.

Appearance:

• With time, copper can develop Verdigris.
• It must be readily cleaned with a good amount of vinegar and a bit of elbow grease.
• Copper takes more effort to maintain than stainless steel.

Durability:

• Copper is softer than stainless steel.

Workability:

• Copper is easier to bend than stainless.
• If you want to build your own, copper is likely your material of choice.

Heat Transfer:

• Copper is an excellent thermal conductor.
• Copper conducts heat twenty times more efficiently than stainless steel.

Advantages of copper:

• It has the highest heat exchange rate.
• You can manipulate it easily.
• Soldering, welding, or brazing is easy.
• Over time, copper develops a stable oxide layer that’s dull and corrosion-resistant.
• Copper and other trace minerals are good for yeast.

Disadvantages:

• Copper can develop a green-blue oxide called Verdigris. It is water-soluble and can contaminate your product.
• Not as rigid as stainless steel

What Is the Price Difference?

This is a common question when considering which still is appropriate for your setup.

Currently, copper costs between $3.55 and $3.90 per pound. Stainless steel is much cheaper at between $1.00 and $3.00 per pound, depending on its quality.

Stainless steel is cheaper than copper as it has lower heat transfer qualities. Stills made from stainless steel are difficult to control and adjust during distillation.

The qualities of copper allow for better control and stability and will improve the outcome of distilled alcohol in terms of flavor.

Copper does tend to tarnish quickly and is more difficult to clean than stainless steel alternatives. For a lower cost, more durable, and easy to clean alternative, stainless steel is your best bet.

A Simple Upgrade – Add Copper Mesh To Your Pot Still Column

To upgrade your setup, it’s possible to add copper mesh to a stainless-steel column to remove the sulfates.

These copper scrubbers serve two purposes:

1. They provide a large surface area for the sulfides to contact
2. They cause a natural reflux action which helps the water to condense. The vapors continue through the column, improving the quality and final proof of your alcohol.

The copper scrubbers are rolls of copper mesh that you can insert into the column. You can usually roll up about 3-4 feet of mesh and after inserting it into the column it will stay there with just friction holding it in place.

Our recommendation for a good copper still for beginners

WMN_TRULYSTEP Home Distiller

This is a great still for beginners. Its ease of use, convenience in design, and cost-effectiveness make it the perfect choice for new distillers.

The design is convenient. It is the size of a large kettle, so it is possible to operate this equipment from your kitchen and is perfect for people with limited space.

Cooling water pipes and tubing are all included, so there’s nothing extra to purchase.

All you need to do is follow the instructions provided, heat your pot, and wait for it to go through its process before enjoying homemade alcohol.

An added advantage is its easy maintenance.

There’s less cleaning and maintenance, so you get more time to focus on enjoying the process. All you need to do is simply wash it out after each run, let it dry and then store it away for the next time you use it.

To purchase a quality still, you could spend a minimum of $500. Which is more than enough to get started as a beginner.

The WMN Trulystep gives the beginner distiller a quality product that will last them years for a fraction of the cost of competing products. You can use this distiller for making small batches and to test new flavors and ingredients. It does this without wasting much alcohol when experimenting.

VEVOR Alcohol Still

This DIY Alcohol Still is a copper still best suited for beginners as it’s easy to operate.

The alcohol still kit uses an open cooling method. The copper cooling tube has great thermal conductivity and offers a larger contact area with the coolant.

As a whiskey still, the cooling performance is excellent and production speed is impressive.

All parts of this kit are food-grade materials, lead-free, and with high temperature, acid, and alkali resistance.

The fermenter barrel is specially thickened. It supports a variety of heating methods including:

• Gas stoves
• Induction cookers
• Electric ceramic stoves
• Firewood, etc.

The buckle provided on the lid and the silicone gasket makes for a perfect seal.

There’s a built-in thermometer made of metal that displays both degrees Celsius and Fahrenheit. So, you can accurately monitor the fermentation temperature during use.

Water inlets facilitate efficient cooling with outlets on top and bottom.

You can use this still to make a variety of products, such as whiskey, scotch, rum, tequila, brandy, and vodka. It also offers the ability to distill water, pure alcohol, and essential oils. As an added extra, you can install a one-way gas valve on the lid of the alcohol distiller depending on your needs.

$119.99

Pros:

• Excellent cooling performance
• Increases wine production speed
• Multiple uses – various beverages

Cons:

• Expensive

Seeutek Alcohol Still

This still is suitable for both beginners and professionals.

The kit adopts an open cooling method, and the copper cooling tube has good thermal conductivity as well as a larger contact area with the coolant.

Each part of the distillery kit is made of food-grade materials. They are lead-free and offer high-temperature acid and alkali resistance.

The fermenter barrel has a thicker construction and supports a variety of heating methods. You can heat the equipment using a gas stove or even an induction cooker. Electric ceramic stoves, wood-fired stoves amongst other solid fuel stoves are also options you can use.

There’s a built-in metal thermometer that displays both Celsius and Fahrenheit.

The alcohol still comes with a thumper keg, which adds a unique aroma during the alcohol distillation.

The Still has multiple uses, which include making any of your favorite beverages, such as whiskey, scotch, and vodka. Distilling water and essential oils are also an option.

$159.99

Pros:

• Multiple uses for various alcohol
• Thumper keg – adds a unique aroma during alcohol distillation.
• Durable

Cons:

• Expensive

Copper Moonshine Still

Not only will you make great-tasting alcohol, but you’ll do so using a high-quality, copper moonshine kit.

The entire still is copper with a distinctive onion head, potbelly, and condenser.

There’s a detachable thermometer attached to the head which is easy to remove or replace.

It is a better option than a stainless unit as the copper removes unwanted sulfides for a superior taste and aroma.

This versatile still is suitable for distilling fruit wine, water, or brandy, as well as plant extracting.

This is a unique product suitable for both professionals and beginners to use at home.

$499.00

Pros:

• Superior results due to copper construction throughout
• Simple construction is easy to keep clean
• Beautifully crafted

Cons:

• Expensive