Home Distillation of Alcohol (Homemade Alcohol to Drink)
Materials to Use for Construction
Summary
Use lead & cadmium free solder or brazing.
Both aluminium and copper are safe to use, but stainless steel will
prove more durable and easier to maintain.
If you do need to make a still yourself, take care to avoid lead solder,
etc which could contaminate ya. Use silver solder instead. Use only food grade type
materials (eg stainless steel, glass, etc). Mine has an aluminium head on it - which
is OK for the limited use it gets, provided it is kept clean & dry when not in use
(or else it will pit & erode).
Copper is an interesting case - high levels of it are known to be dubious to
your health, however it has been (and will continue to be) used for centuries
in commercial stills (because of its excellent ability to transfer heat).
This is because any dissolution is at such a low rate that you don't get exposed
to enough of it. It is well known that the low wines produced in commercial stills
can be a light green in colour due to their copper pick-up, however they are
still below limits prescribed for potable water by health authorities. It would
also appear that the copper helps convert some of the esters & organic acids present
(which affect taste and odour), so that they're reduced. Some people who have built
stills without copper have later added some back in (say using copper srcubbers for
column packing), to because their highly pure (93%+ purity) spirit still had a
smell present, which only went away when they put some copper in the vapour path.
... I made sure the buckets were at least 0.090" (90 mils) thick by
checking the thickness "rating" embossed on the bucket bottom --
I found that the cheapo 0.070" buckets I experimented with earlier
on allowed the element to sag when it got hot, but the 90 mil units I
found were just fine. I ended up changing to a 7-gal HLT (see below),
same as my boiler. These 7-gal buckets are both 100 mils thick and
handle the heat very well.
Wal writes ...
I obtained a cheap used 60l (25 USgal) plastic drum with a band clamp
like those on paint tins. Looked more solid than my plastic jug in
the kitchen. So I obtained 2, 240V, 1500w electric jug replacement
elements which can be easily attached to the drum by simple drilling
and screwing tight (from ray@moonshine.co.nz). Converting beer
barrels and hot watersystems did not appeal to me - I like easy
solutions as I'm not a great handyman. I intend to use two for the
initial boil, and then use one for my 40mm diam X 1m column which
appears right to prevent flooding.
Appears HDPE and polypropylene are O.K.
Utilization temp (deg. F) for HDPE is -180 to +248 with a melting
point of 266.
Utilization temp (deg. F) for polypropylene(PP) is -15 to +266 with a
melting point of 338.
Oviously polypropylene is better, but high density polyethylene is
acceptable.
Plastics are slightly permeable so be careful what they held if
purchasing a used one. The inside of my kitchen plastic jug looks vey
stained, but then so what.
Galvanised Metals
Tarvus explains ...
Galvanised materials are not safe to use on the condenser side, but if it's part of the
boiler or at the bottom end of the column, it should be fine
(provided you don't boil so vigorously that your wash bubbles up
through your column and into your collecting container. Toxic salts
from metals can be dissolved in liquid, but remain behind when the
liquid is vaporized (as in a reflux column).
For example, you could toss a handful of lead fishing sinkers into
your boiler which could well leach toxic levels of lead into the
wash. But once the vapor runs through the column, it's free of the
lead salts and safe. If you used lead based solder (or galvanized
parts) in your CONDENSER, that would be a different story. The hot
liquid condensate could leach lead salts from soldered joints or zinc
from the galvanized parts and you would wind up with contaminated
product.
Solder & Braizing
(A compilation of newsgroup emails by Robert Warren,
Pete Sayers, David Reid, James Witten, Howard Anders, Allan Goldsmith
& Scott (the yldog) - thanks guys !)
Solder
Is solder safe to use ?
Tin and silver solder is perfectly safe, and in fact is commonly
used for soldering copper and/or stainless steel for food use.
The main "ingredients" in solder we need to avoid are cadmium and/or
lead. BTW tin is the material used to coat the inside of "tin cans"
in making of canned foods - ie its very safe to use (Actually steel cans of course, which are
plated with tin to make them corrosion proof.)
Most states in the US outlawed lead solder back in the mid 70's.
There are a couple types of solder currently sold on the market:
Silver solder, is mostly tin and a small
amount of silver. It does take a bit higher temperature to get it to
flow, but has excellent adhering properties. In fact, if you want to
solder something which will never come apart, unless you use an even
hotter torch than what you soldered with in the first place, then
silver solder it. You may want to use Mapp gas instead of propane
to get the higher flame temperature (around 650 F / 345 C ?).
Regular silver solder may have some cadmium in it; Check that you
are infact using cadmium free silver solder (for use on food related equipment (stills)).
The other main type of solder is simply called 95/5,
which is 95 % tin and 5% zinc. It flows easily at a lower temp,
(around 500 F / 260 C ?) and will just run off instead of sticking if you get
the joint too hot. You want to work this solder at close to the
melting point. This is what most plumbers have used on domestic
waterlines arouund the world for the past 25 years, and it is
completely safe, as is the silver solder. Plumbers use 95/5 because
it is about 25% cheaper than silver solder.
Now, given the fact that alcohol is a known solvent, and the
other salient fact that you have hot alcohol vapors inside a still,
it is reasonable to wonder about the how much tin and such may
dissolve. Well, the tin is pretty good at sticking to the copper
and also to the adjoining tin molecules, and it really is not very
soluable at all. Some geographical areas have well water which is
highly aggressive, perhaps a stronger solvent than alcohol. Such
water will dissolve out the zinc in galvanized pipes and then
continue to react with the iron underneath and you end up with holes
in your pipes.The zinc on alvanized pipes and inside water heaters
is considered a sacrificial metal. However, the zinc in 95/5 is bound
to the tin and is an alloy, so it has completely different properties
than the zinc coating on steel pipes. Anyway, the long and short of
it is that zinc, tin, and copper are found in tiny trace amounts in
our bodies along with gold and silver.
Brazing
Brazing definitely makes a vastly superior job to soldering and
is also more permanent too.In short there are a number of materials;
Silbraloy (sometimes mistakenly called
Silvaloy) at the bottom of the range starting with 2% silver,
Silphos with 5% and 15% forms and one or
two other proprietary materials, and
Easyflows which have silver contents
from 30 to 56%.
The Silbraloy and Silphos forms are generally a
mixture of silver and phosphorous copper whereas the Easyflows also
contain other specialized minerals to achieve certain other goals eg.
nickel is used for hardness.
Silfos is an exellent product to use. It takes a much hotter
flame, so you may need to use Mapp gas or even acetylene (it melts
at around 800 F / 425 C ?). Quite high, compared to solder. It is a phosporous
bearing product. It is unique in that you don't even have to flux
the joint, but it should be thoroghly clean,as with all soldering.
It is very strong, and the other feature is that it is strong enough
to use to repair a hole in apressurized water pipe (you can't solder
with water in the pipe) but it can be worked like a brazing rod and
so you can fill holes with it.
Prices start at around NZ$30 kg and go up
to NZ$400 kg for the more specialized materials. The more silver and
other additives the higher the price.
Also in short you get what you pay
for and the skills and experience of the welder then become important.
If you have a good welder he could probably use Silphos 5% but I would
probably use 15% ( Good capillary flow for tight up joints. High stress
resistance) if you want a good neat job and you dont mind spending a
little more. Either Silphos 15% or a bottom end Easyflow (such as 30%
but a bit dearer again. Good gap filling and build up. Good flow
characteristics) are probably the best for this job and the little bit
more you pay for the material are generally compensated for in the
welding time saved. Personally I wouldnt pay more than $80 kg. Consult
with your welder as he is the guy with the experience and as long as he
is honest and has the skills you should be pleased with the result. If
he is an older plumber who did his time using copper plumbing pipe you
should have no problems.
There has been a good deal of "discussion" as to whether or not the
use of aluminum in brewing contributes to Alzheimer's disease. Thanks
to Oliver Weatherbee for providing to following:
Aluminum has NOT been linked to Alzheimer's disease. The following is
taken from "Frequently Asked Questions About Neurological Problems" at
The Department of Neurological Surgery of The Cleveland Clinic
Foundation (http://www.neus.ccf.org/patients/faq.html):
"There is little support for the theory that aluminum causes
Alzheimer's disease, the most common cause of dementia in the United
States. The exact cause of this disease is unknown, although the risk
of Alzheimer's is higher when there is a family history of this
disease.
[two paragraphs removed]
Workers exposed to high levels of aluminum in industrial environments
have no increased incidence of Alzheimer's disease. Furthermore,
careful studies to date have not shown an increased aluminum
concentration in the brains of Alzheimer's disease patients.
Since there is no convincing evidence linking aluminum toxicity with
Alzheimer's disease, you need not worry about exposure to aluminum in
cooking utensils."
Furthermore, Brewing Techniques (Jan/Feb '95) had an article on a
parallel brew experiment using an aluminum brewpot and a stainless.
Laboratory analysis showed that there was no significant difference in
trace aluminum levels between batches. They also pointed out that most
of the Al you digest is from your food and water. And for that matter,
many medical people consider copper a bigger health risk.
As for off flavors, IF this happens (hearsay IMO), it is probably the
result of the brewer scrubbing the oxidation layer of the pot during
cleaning. Don't scrub, use a soft cloth or sponge and non-abrasive
cleaner. This is one of the reasons Al is not used much commercially,
its not caustic cleaner friendly.
About the biggest concern is using aluminium to stew up highly acidic
foods (eg tomatoes), where a very long time comes in to play. For more details
see ..
Do not use sodium hydroxide (NaOH) - lye - for cleaning with aluminum!!! the reaction will
produce hydrogen gas and eat the aluminum. Treat aluminum like you would
copper.
Is Copper Safe to Use ?
Copper has been used for centuries in still design, despite its slight solubility.
This is primarily due to its excellent heat transfer properties, making it excellent at
cooling the vapours. Although some copper will leach into the distillate (low wines are sometimes
a light green in colour), it is usually well below health limits for potable drinking water.
If you haven't fully rinsed
off acids used during cleaning, then it can react to form copper acetate (verdigris).
This stuff is toxic, with an LD50 (Ingestion) of 196 mg/kg (mouse). This is a small number -
it means that a 90kg person would need to consume 17.6
grams of it (half a scrubber by weight ?).
This stuff is slightly different from the "green rust" you see on copper
if it isn't dried fully each time after use. However, all copper salts are
toxic if consumed in chronic volumes.
2-5 mg / day is essential for good health, however levels above this will be
dangerous. 10-20 g is considered fatal.
Your body will slowly flush itself of copper, but
approx 30% of copper salts ingested will stay in the body.
The half life is 13-33 days with 70-150 days to completely clear any
one incidence of ingestion. In simpler terms, we're not at risk in using copper for the
fittings in the still, as the rate at which we're oxidising the copper is a lot slower than
rate our body can handle it. In addition, given that the reacted copper is water soluble, a
decent rinsing after each cleaning & use of the still should take care of removing it.
The greater likely risk is from inhaling the dust when cleaning dry copper.
Make sure that you do your cleaning in a well ventilated room, and possibly use a mask if
you're putting dust into the air.
It would be rare to find a commercial distillery that didn't use copper.
Several sites actually recommend some benefits from using copper, as it is
said to remove sulphur & form more esters (flavour)
According to relevant literature, copper should theoretically reduce the amount of
esters/organic acids because of its catalytic impact. Basic rules of
organic chemistry point to the same outcome. But we didn't notice any
difference in taste/smell when distilling simultaneously with two
equipments, one was completely made of glass, the other one of copper.
The fermentation has a much greater effect on the result. Esters and
especially organic acids arise from misfermentations of leafs/twigs or
rotten parts of fruit. Work as clean as possible during the whole
fermentation process and use cultivated yeast. Then you shouldn't have
any problems with esters/organic acids.
Try this: Fill a copper-tube (length appr. 30-50cm) with copper wool.
Put this tube between the distilling pot and the cooler (condenser)- you SHOULD notice a difference.
The size and shape of the stills are crucially important. The more contact
the wash and low wines have with copper the better, since it acts as a catalyst,
removing sulphury impurities (in the wash still) and promoting the creation of
esters (in the spirit still) - effectively cleaning and lightening the spirit.
Small stills with a broad 'head' (the middle part of the still), such as those
at Macallan, are best of all: a narrow head tends to increase the velocity of the
ascending vapours and to reduce their contact with the copper walls.
Finally, while we are on the question of still design, there is the
important matter of the length and angle of the 'lyne arm' - the pipe which connects
the top of the still, known as the 'swan neck' to the condenser. Macallan's lyne arms
are of average length, but they are acutely angled in a downwards direction. This
means that once vapours reach the neck of the still they are more likely to go
over and be condensed than to fall back as reflux and be re-distilled. Again, the
Macallan is unusual in this: most distillers set out to increase reflux. But then, they
may well not achieve such copper contact (with its spirit-enhancing properties)
as do Macallan's small stills.
Cleaning Copper
Ted advises ..
If you used bleach or any other high pH cleaner, the inside of the copper
tubing will corrode and give off dark colors. If you weren't using corroding
cleaners then you're not as clean as you think you are. The best cleaner for
copper tubing is mild acid like phosphoric or nitric acid. Run a gallon of
5% acid though it about 10 times and rinse with 2 gallons water.
If your still is made of copper NEVER clean it with bleach!
In fact, it doesn't matter what your still is made of, DON'T USE BLEACH! it
corrodes just about every metal out there. I seem to say this over and over
but no one listens!!!
Bleach is great for sanitizing glass, plastic and wood fermenters and is the
only place that you should use it.
David agrees ...
Use Hydrogen Peroxide instead in most
applications. This tends to sterilize rather than just sanitise and it
also just breaks down to water and oxygen unlike bleach which kills fish
and plant life including algae and which end up polluting waterways and
the enviroment generally. The chlorides in bleach also attack and destoy
metals including ss. This is a point that has irked me for years and one
in which the so-called more advanced civilized societies and man in
general are so backward and dumb. The only place I tend to use bleach is
a few drops in fermentation locks so algae and bacteria dont grow and a
little in the bucket of washing liquid when I mop the floors.
Jack offers ..
I just found the perfect cleaning agent for copper. Since I can't get nitric
acid, I decided to use whatever acid I had on hand: VINEGAR! I took a copper
elbow that was brown, streaked, and corroded and totally covered it with
vinegar. In about 20 minutes it was bright and shining. No scrubbing or
anything, just a soak, then a water rinse- spotless copper. Try it, it's
worth it.
Gaskets & Seals
Tarvus gets back to basics ..
A bit of white bread and water kneaded into a dough like paste works
as a good temporary seal. Use it like a putty. It will dry but
retain an airtight seal.
Jan Willem writes :
I made a still with a soup pan and a doughbowl, the seals I tried
were;
rubber gasket - too stiff and smelly
silicone rubber tubing sliced open - well ok sort off, not perfect
silicone gasket or as the packing say's Form-A-Gasket no.6
I aplied it as a thin stripe and let it dry.
Now i placed the dough bowl on it and fastened it (check my
website
I don't know exactly how to describe my contraption)
Its been opened and closed now for about 15 times and still ok.
And when its damaged easy repair or exchange with a new layer.
Oh the manufacterer is Loctite and its called Blue Silicone RTV
Catalog number 18869 and is also sold in europe
Gateswood Quarterhorses confirms this as suitable;
High-temp RTV is stable to 650° F. (intermittent) and resistant to most shop
fluids. I assume this could include alcohol. It is also pressure resistant. Not
recommended for contact with gasoline but I've had no problems with diesel fuel.
I would think that after it has fully cured it would be safe and effective for
patching a still.
Rob van Leuven writes :
I have used a so-called aquarium grade silicon; after it has cured
completely and the vessel (or fishtank) has been rinsed with water a couple
of times, it does not release any chemicals. If it did, it would kill the
fish immediately, because they are especially susceptable to chemical
pollution (especially sea fish).
The sealant/adhesive is resistant to temperatures up to 150 Celsius and
inert to most solvents, acids etc...
If you want to make a removable gasket, you can squeeze a large blob of
sealant between two panels of melamine faced chipboard which you have
previously covered in dishwashing detergent (fairy liquid). Don't forget to
separate the two panels with spacers which have the same thickness you want
the gasket to have. After it has cured completely you can cut out the right
shape with a sharp knife; put the gasket in boiling water for a while to
remove any residues and you have a longlife silicon rubber gasket!
Necessity is the mother of invention as the Irish say:)
How to connect the column to the pot lid ? Scott writes ...
use a sink strainer. Mine is nickle plated
bronze that goes for $10 here in the US. It has two thread
diameters. The larger one is screwed into a hole in my lid that I
cut and rounded with a Dremel (this takes a bit of patience). An
added bonus is that the strainer has crosshairs that keep the packing
out of the pot. The smaller diameter screws into a female, 1.5 in.
copper fitting that costs about $4. An inert rubber gasket or
aquarium grade silicone provides the seal. I used a beer mini-keg
gasket that cost me $1. I also use a bit of PTFE tape on the thread
just to be safe, and this cost me $1.
The boiler is a 20 quart, el cheapo s.s. stock pot that I got for $14
at "McFrugals" here in California. Because it's thin steel, I use
pipe insulation tape that runs for $5.
So, the total cost, minus the Dremel, was $35 US for the strainer,
pot, gasket, PTFE tape, copper fitting, and pipe thread.
In the photos section, you might have seen the
pictures of Rays Keg still. Here's how he did it ...
I cut the hole out with a friend's plasma torch. I make a
fixture using the top piece of the original valve (see the large ring) which
fits perfect into the opening. Next, I used a brass nipple, cut it, and
turned the inside diameter to match he plasma torch tip. I silver soldered
it together using welding rod bent to match the radius of the keg. Kind of a
kluge, but it worked well. Here are some pictures of it with the cut out
piece.
At first I had leak problems because the hole I cut into the keg was so
close to the seal, it had to be centered exactly, or it leaked. Using the
same seal, I cut a polycarbonate disk and placed it against the seal, added
a gasket and it worked fine. Leaving a flat surface for the seal, and the
keg convex top cant miss the gasket. The gasket width gave me a lot more
flexibility with centering to the hole. You can see the line around the
opening, the original seal locates inside the line.
Next, I built another lid (untried as of yet) but cut a .5" wide, .075 deep
grove around radius, which will center on the keg opening and filled it with
RTV. It should be reusable several times, and it fits really nice.
The first pix shows the 2-15 degree angles on the copper disk edge, that
really helps keep the seal (black) in place. I use a brass pin in the bottom
of the column to hold the packing in place, easy to remove so the
polycarbonate disk can be slid on.
While I was making plastic circles and a big mess in the garage I cut this
one to fit a stainless pot with a flat edge. I used a paper gasket, and lots
of clamps to hold it down, that's how I got the mini model (see the
photos page). This looks lots simpler without clamps.
And, last but not least, (while I was continuing the mess in the garage) I
made a smaller disk and put a hole in it to match a carboy. Now, the
standard fermentation lock and cork will fit, and I can use the keg for a
ferment container. Still working on a good wort recipe, after that I'll try
this setup. The brown protective paper is still attached, that gets removed.
Thomas suggests ...
Another way to attach the column after the ball valve spear is removed is to
use a 2" tri clamp. A 2" tri clamp fits perfectly around the lip on top of
the keg fitting and clamps the column onto the keg tight. Granted its not as
easy to clean (i have a ball valve on the bottom side) but sure is easier
than building that top assemble.