Reflux Guide for Noobs

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MidnightThunder
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Reflux Guide for Noobs

Post by MidnightThunder »

I recently sold a 2" VM column and boiler that I had retired from use and wrote up a guide to use for the purchaser of it. I included all that I could figure would be needed for someone new to distilling, to be as comprehensive as possible. Some members and visitors might find it useful. Enjoy.

An Intro to Distillation

Distillation is all about chemistry. But that doesn’t mean you need a degree to understand the basics of it. At its core, it separates compounds from a mixture, based on their different boiling points. This means the further apart the boiling point of two compounds is, the easier it will be to isolate them using distillation.

The Ferment

The first step in any distillation run is creating the solution to be loaded into the boiler. In the instance of distilling spirits, you will start with the fermented wort, known as a mash if its sugars originate from starches in grains, or called a wash if its sugars come from simple carbohydrate sources such as fruit, honey, white sugar, or high fructose corn syrup.

Mashes carry unique ingredients depending on the particular grain used and also contain most of the nutrients required by the yeast to grow strong and healthy in order to complete an efficient and vigorous ferment. These ingredients are what impart much of the flavor to whiskey, while the other portion of taste results from barrel aging. However, mashes come with some drawbacks. The trouble starts at the mashing procedure wherein enzymes in malted grains convert the starches to simple sugars and are extracted from the hull of the grains. The first issue is that due to the conversion process occurring in the mash, this procedure takes roughly an hour to complete. Additionally, the wort has to be separated from the grain hulls utilizing either the lauter process or the Brew-In-A-Bag method, BIAB being the easier of the two. Finally, you are then left with many pounds of hot grain to dispose of. For these reasons, grain mashing is recommended only after sufficient experience is acquired running the still with easier wash ferments.

For the initial handful of distillation runs, there is no better charge to load the boiler with than a simple sugar wash. This is a mixture of water, white sugar, nutrients and yeast allowed to ferment for as short as 3 days and typically up to a week, contingent on yeast health and proper temperature regulation. It ferments to a wash with little flavor, sufficiently suitable for creating Grain Neutral Spirits, GNS, that can be diluted down to vodkas, gins, and other mixed drinks. The highlight of simple sugar washes is their ease of preparation. All that is required is heating the pot of water enough to dissolve the sugar, adding a nutrient blend, cooling the mixture, and pitching yeast. The wort is then left alone in a cool dark place and will start to show signs of fermentation after 12-24 hours. Fermentation is underway when bubbles begin to emit from the wash as carbon dioxide is released. When it stops bubbling and a taste test doesn’t reveal any remaining sweetness, the yeast has consumed all of the sugar and the wash is now ready to distill.

If after a few runs of simple sugar washes a product with more flavor is desired, washes can be made with fruit, honey, or molasses added either in addition to or in place of the white sugar. Using fruit will yield a brandy, molasses a rum, and honey a spirit in between the two. Flavored washes are as easy to prepare as a simple sugar wash and can reward you with some delicious tastes.

The Equipment

While the quality of a ferment is the single largest factor of making a great product, the second variable determining quality is the type of still used. A still is a tool, and as with everything, it’s important to have the right tool for the job. There are two types of stills: pot stills and column stills. A pot still is primarily used for making flavored spirits and a column still for producing GNS. There is significant overlap between the use of them, but remembering the fundamental role they each serve will save a lot of trial and error when chasing a certain style of spirit. A pot still is simply a boiler with a condenser connected to it to catch and cool the vapors being produced. This means that one run through a pot still will only yield a single distillation. For flavored spirits this is useful as only a bit of separation is desired. The flavor in brandy, rum, tequila, and whiskey is actually imparted from minute traces of other byproducts formed by yeast from the fermentation process, such as methanol, isopropanol, butanol, acetone, and aldehydes. A column still on the other hand performs the equivalence of numerous distillations in a single run, outputting a higher ABV purer product. This is the optimal still for producing vodka and gin, as one run will yield you much a cleaner neutral to be cut down with water or infused with any botanicals. Each subsequent distillation of the collected distillate from a run will further remove congeners and yield a cleaner product that in addition to less objective taste will also give less of a hangover.

The overlap of the two types is that the product can be run through a pot still multiple times for the same purity yielded by a column still, it just takes more work as at least 4 to 5 runs would be necessary. Similarly, a column still can also produce flavors like a pot still outputs by mixing in parts of the heads cut and tails cut into the hearts. While both can be used interchangeably, respecting their unique roles will save you a good deal of unnecessary work.

The Setup

The first step in getting ready for a run is to check over all the equipment and ensure every component is in good condition. Before filling the boiler and setting everything up, connect the water and check for flow through both condensers and confirm there is no blockage. So long as they have water, they’ll be able to condense the alcohol vapors produced during the run. Now you can fill the boiler with either a fermented wash or collections of previously distilled product. If filling with a wash, fill to a max of 75% boiler capacity as the contents will foam up when starting to boil and this will give them enough head room to not puke into the column. If filling with previously distilled product, the boiler charge can be filled up to within 3 inches of the opening and should be cut to below 40% ABV for safety of minimizing fire risks. With the boiler filled, the heating elements may be plugged in to start the heating process during the rest of the still assembly. Attach the column to the top of the boiler and connect the water lines. At this point it is best to run a small trickle through the condensers while the boiler contents are heating up to ensure that even at the start of evaporation, no alcohol vapors will escape the column. Close the takeoff valve so that all vapors will be directed to the reflux coil. The heat up time for 6 gallons will be 30-40 minutes. As the contents begin to approach their boiling temperature, the noise from the boiler will continue getting quieter. Feeling the temperature at the bottom of the column, you will be able to tell when the contents have begun to boil, as the column will get too hot to keep a hand on. At this point, turn the flow of water up to a steady stream and keep an eye on the top of the column to ensure you have enough cooling power to prevent any vapors from escaping. For sake of conserving water, you may cut the flow of water down to where the exiting temperature is 140 degrees Fahrenheit, or if not using a thermometer, until it is hot enough that you can only hold a finger under it for a second. The still is now boiling the contents of the boiler charge, where the vapor is being condensed by the reflux condenser, and dripping back down through the packing. The condensed reflux is mingling with the hot vapors exchanging the heat from one another to drive alcohol further up the column and water back down to the boiler. For the reflux still to perform its duty of fractionating the various compounds in the vapor, they must be able to stabilize in the column, wherein it stacks those compounds with a lower boiling point at the top and higher boiling point compounds at the bottom. For this to occur, the column will need 30 minutes after reflux has begun where it is left to reach equilibrium, before opening the takeoff valve and collecting product. After it has stabilized, It is time to distill!

The Process

With a container under the product condenser, the takeoff valve can be opened small amounts at a time, as you want to try not to disrupt the equilibrium in the column by opening it to quickly. The compounds at the top of the column and the first to be pulled off will be the foreshots, so you will want to collect at a slow rate of 1-2 drips per second. The foreshots primarily consist of methanol along with small amounts of acetone and other lower boiling point compounds so they are to be isolated from all of the other product. They can be used as fire-starter or cleaning solution but should not be drank, as they are toxic even in amounts as small as 100mL. For a 5 gallon run, the first 4 ounces can be considered foreshots. After the foreshots have been pulled, shut the takeoff valve to allow the column to equilibrate, for 10 minutes. Now, with a new container under the product condenser, open the takeoff valve slightly more than where it was before to begin pulling the heads. Heads are ethanol contaminated with just enough of the compounds from the foreshots to affect their taste but are still safe for consumption, although they will likely give you more of a hangover. The takeoff valve can be opened a little wider until there are many drips coming from the product condenser a second. The amount of heads that you will collect varies from each wash and is based on personal preference so this is where you’ll start making your cuts. You will have to decide where to make the heads cut into the hearts cut based on taste. Do not be afraid to stretch the heads cut larger than it needs to be, until you are firmly in the hearts, as heads can be added to the tails cut to make up the feints that can be redistilled once you have a boiler full collected after multiple runs. At the time that you are in the hearts, switch to a new container and open the valve to the point that a continuous stream pours from the condenser. Hearts will be the bulk of collection from a run and are the best tasting spirits produced. Continue collecting until you are able to detect a difference in taste. At this point you are nearing the cut to tails, but you are able to prolong the heads collection by closing the takeoff valve and allowing the column to re-stabilize for another 15 minutes. Now you can open the takeoff valve to where it will output a few drips a second and continue collecting until you detect a taste difference again. At this point you are at the tails cut. Tails are not always collected on a reflux still, as they may not be considered worth the amount of energy required to pull them, so you must make the decision on where to end the run. If you want to get all the alcohol out of the wash, switch to another container and continue collecting, for as long as you desire, to add with the heads for another run. Remove power from the heating elements, and then shut down the water flow.

At this point, you are done the run. You now have your product, separated into heads, hearts, and tails. It is easiest in the first few runs to collect your output in many smaller containers so that you can visit them after the run and determine based on smell and taste which ones will comprise which cuts. The amount of each will vary based on each wash, but after running the same recipe wash a couple of times you will get an idea of how much to collect for each cut. Flavor will be the determining factor.
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Evil_Dark
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Re: Reflux Guide for Noobs

Post by Evil_Dark »

Very nice wrap up operating instruction!
You should rename the title of the topic as "VM Reflux still for noobs".
I came across your post while searching exatly for this, except for operating a CM reflux still. Same principle, but the fine tuning adjustments and startup is slighly different...

Thanks for this valuable post!
Evil_Dark
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