Salt in the wash

[dStill]

What exactly does salt do when put in the wash before distilling? and is it recommended?
I tried it out, but other than making the water boil at a lower temp. I don't have enough experience to really know.

the manual has this info Is there anything anyone can add?

Salt
Maurice advises ..

..put a teaspoonful of ordinary table salt into the wash ..the spirit comes over much better..

Salts are sometimes used during extractive distillation (eg when trying to distill past the 95.6% azeotrope) so as to depress the volatility of the water (eg effectively increase its boiling point, so you get a greater % of ethanol off compared to normal). Because the salt is non-volitile, it will always remain in the pot, and not turn up in the distillate.

The "Household Cyclopedia" recommends ...

Table-salt thrown into the still, in the proportion of 6 oz. (180 g) to 10 galls. (38 L) of any liquid to be distilled, will greatly improve the flavor, taste, and strength of the spirit. The viscid matter will be fixed by the salt, whilst the volatile matter ascends in a state of great purity.


David cautions though ..

make sure you use ordinary non-iodised salt not iodised. Virtually all salt sold in NZ in containers for domestic consumption is iodised. Also be aware that salt is sodium chloride and that chlorides attack stainless steel and can bad pit it. It can also and will generally shorten your element life.


Bokakob advises ..

The best time to introduce salt in the distillate is when distilling second time. The first distillation, stripping, is used to reduce the amount of liquid and some of impurities. The second run is the place where this salt helps in separating boiling point of water. I always add regular salt for the second distillation in proportion of about two heaping table spoons for about 8-10 liters of 65% abv.

[rad14701]

Salt tends to lower and stabilize boiling temperatures, which is why it's used for boiling water in the kitchen... I doubt that many distillers use salt unless needed for a specific reason due to the composition of the wash... For example, it can help when distilling a wash with an excessive amount of foreshots and heads...

[big worm]

i kinda figured that salt and etho will not mix so if water bonds to the salt it must let go of the etho making it a better sepperation of the two. i tryed salt a couple of times but never seen any value in it, because i try to keep flavors from the water in the whisky. it may make a cleaner neutral from a reflux still. other than boiling point who knows.

[DrTorque]

Salt RAISES the boiling point of water. There's contradictions in this very thread.

It's used in the kitchen mainly for taste, but boiling salt water will also be hotter and cook foods faster. Salt water also has greater thermal conductivity, so it heats up faster.

The amounts of salt mentioned above won't raise the boiling point very much, though. I think you're looking at less than a degree. I don't see how that would make much of a difference in distilling. I thought things like this and baking soda were added to the wash to help clean it up because they chemically bonded with unwanted substances.

It's awfully corrosive, too. I'll stay away from it.

[rad14701]

Yes, DrTorque, you are correct, with one exception... When I use salt I never stir to to dissolve it and as it sits on the bottom of the pot it creates nucleation points which may or may not make it appear that the water is boiling faster... It may well be just a matter of keeping occupied during that "a watched pot never boils" phase as I've never timed it and am well aware that pure water should always boil sooner than water with impurities... We always think our superhuman powers will speed the process... I have to agree on the caustic effects of excessive amounts of salt, which is the main reason I never use it during distillation...

[MuleKicker]

so salt raises the boiling point of water, and does nothing to the alcohol? I have known and used salt to raise the boiling point of water for quite some time, and it would make sense if you could raise the water's boiling point without effecting the alcohol boiling point. But is that the case?

[big worm]

etho and salt do not mix. by raising the boiling point of water i think less water is carryed over in the run...at least thats the theroy i guess. some sites have sugested using salt to dry off alcohol for fuel making because it will absorb water and repell the etho.

[DrTorque]

I can't find a damn graph that shows how much salt raises the BP. I've seen the melting point graph for water-glycol, but I don't think I've ever seen a boiling point one. If anyone can find one - look for concentration vs. boiling point for salt water.

Salt should help the separation of water - ethanol, but I don't think that's of much use to the moonshiner. Separating water from ethanol is not really a problem for us - and our goal is rarely to get all of the water out. The problem is separating the ethanol from all of those other chemicals that we don't want. Unfortunately, those other chemicals are things that won't dissolve salt, either.

I guess my main point is that using salt has it's drawbacks, and it's not worth it for the minimal gain you will get in separating a little more water from everything else.

[big worm]

water = flavors,flavors take away from neutrals. thats the only reason i could think of. who knew about distilling untill some one poured some vile smelling crap in a pot and caught the other end.

[MuleKicker]

ok, BW. thats what I thought. You both make some interesting points. I'm big into neutrals so that is why im interested in this. It makes sense if etho does not disolve salt, and the fact that the 5% of extras left in distillate (if your taking of at 95%) makes off flavors. Im sure there are some of the other chemicals and whatnots coming over that salt will not help. Next good point is the corrosiveness of a high salt solution, especially when hot. I am running a stainless rig, with copper packing. I think it would eat the shit out of my packing. I am wondering if its all worth it in the end, and it looks like experimentation and real life experience is the only way to settle this one.

[Aces High]

Skip the salt altogether. The recent tip that I got for my neutral was adding bicarb soda @ around 1 teaspoon per litre of strippped wash. I did the final run through the VM and both the heads and tails were really compressed so I got a much better yeild and the hearts was just beautiful clean neutral.

I am not sure the whys of bicarb, but I just know it worked really well

[MuleKicker]

yeah AH, I do add the bicarb, and your right, it does work.

[Amell]

With water you'll need 60g of salt per litre to raise the boiling point by 0.5c

Perhaps it is some other chemical process at work that causes the improvement rather than just a boiling point issue.

Amell.

[scientistjoe]

Okay as stated above adding any salt be it table salt or bicarb or what ever will raise the boiling point by small degree. This matters little on the type of salt but rather on the number of ions produced in solution. This follows the basic freezing point depression/ boiling point elevation equations:

http://en.wikipedia.org/wiki/Boiling-point_elevation
http://en.wikipedia.org/wiki/Freezing-point_depression

The matter of adding salt prior to distillation is in achieving through the act of solvation some water that is held more strongly to the non-volitile salt than to the azeotrope's vapor composition. some salts are far better at this than others, some act by chemically bonding water such as calcium oxide, This works for small amounts of water but the greater the water the less noticeable the effects and the great amounts of salt are required.

Salting out solutions can also help separate out suspended solids by the salts being preferentially dissolved by water, reducing solubility of other compounds. This can help clear up cloudy solutions and reduce frothing, by precipitating out proteins.

Sodium bicarbonate (NaHCO3) added to the must has an aditional effect on the must besides the above effects in that it neutralizes acids that when present can produce ethyl acetate and other esters when heated or after standing for long periods. The esterification occures because of a process known as Fisher esterificaion:

http://en.wikipedia.org/wiki/Fischer_esterification

If an excess of NaHCO3 will produce a slightly basic solution that can cause hydrolysis of esters back into organic acids and alcohols. This happens very slowly but in effect reduces the ammount of ethyl acetate in the distillate and also prevents its further formation while its being heated and refluxed.

http://www.chemguide.co.uk/organicprops ... lysis.html

Tetrahedron Letters, Volume 32, Issue 3, 14 January 1991, Pages 327-330

In, the end by simply adding NaHCO3 you can produce more define cuts and maybe improve overall ethanol yield.

[mrhooch]

My only comment is that using sodium bicarbonate produces a slightly alkaline wash, ph around 8.5 if my memory serves correct. Sodium Carbonate on the other hand is more neutral. I tried the sodium bicarbonate until it wouldn't fizz anymore, but ended up with a range of new smells, and tastes which I wasn't exactly happy about. It also caused a lot more reactions with the copper in the column.

I haven't tried the sodium carbonate yet, just got a bottle, and am waiting for my birdwatchers wash to settle out and then I'll give it a shot.

Hooch.

[ScottishBoy]

I have used Sodium Carbonate in my final wash for Vodka. I will say that it gave a cleaner product, but it smelled ever so slightly of laundry. I may have used too much. I used four table spoons for five gallons of 45% ABV. Next time, I think I will try just one Tbs for all five gallons.

I think that the purity could lead to exagerated smells, since there was nothing else to smell it up, I think it was easier for the carbonate smell to come through. One other thought is that is IS possible that the carbonate absorbed a smell while it was being stored. I used Arm and Hammer and Im fairly certain that gets shipped in the same containers as the smelly soaps do.

[Whitedog]

ScottishBoy, Sodium Carbonate or bicarbonate?

[scientistjoe]

My only comment is that using sodium bicarbonate produces a slightly alkaline wash, ph around 8.5 if my memory serves correct. Sodium Carbonate on the other hand is more neutral. I tried the sodium bicarbonate until it wouldn't fizz anymore, but ended up with a range of new smells, and tastes which I wasn't exactly happy about. It also caused a lot more reactions with the copper in the column.

I haven't tried the sodium carbonate yet, just got a bottle, and am waiting for my birdwatchers wash to settle out and then I'll give it a shot.

Hooch.

Actually, bicarb of soda (NaHCO3) is just a protonated carbonate ion (CO3-) and therefore bicarb has a lower pKa and would produce a less basic/more acidic solution (pH 8.3) than the carbonate (pH 11.6).

[mrhooch]

Ah I love trial and error.... Not too happy when I get the errors... My adding sodium carbonate to my wash did what was described below.

<Copied from the distilling section blue spirits of homedistiller.org>

Mike warns though ..
It's OK to add baking soda or other alkali to a STRIPPED wash, but NEVER put it in the primary ferment and then distill. If you do, and your still contains ANY copper, you will severely corrode the copper, and get blue, ammonia-smelling distillate. Not fun!

Why? Yeast and yeast nutrient both contain lots of ammonium salts (like DAP), which are very stable under acidic conditions, but which release lots of ammonia as the approach neutral conditions. Actually, you will start getting ammonia at about pH 5! Ammonia gas is very corrosive to copper, and you will find your condenser coil packed up with blue crystals after such a run (and blue alcohol too !)

Schweitzer's reagent is cuprammonium hydroxide, and is formed when copper hydroxide dissolves in a dilute ammonia solution). It is a deep blue colour, and is particularly known for its ability to dissolve cotton. The chemist who first discovered this property was Eduard Mathias Schweizer (1818 -1860), so it seems that it should really be called Schweizer's reagent.

It forms in stills when ammonia released from alkaline washes (nitrogen source may be plant material or yeasts) reacts with copper hydroxide formed by the action of steam on copper oxides coating the inside of copper columns or components. It may be avoided by ensuring that the liquid in the boiler is slightly acid (pH less than 7).

<End of section>

Ah yup, keep your wash acid especially if you add DAP.

Hooch

[scientistjoe]

Ouch Hooch, I guess I'm the odd case in that I'm using a glass still.

I May have been a bit inprecise with my wording in my previous post. Must, charge, wort, mash; I guess I'm not the most consistent with knowing what to call the stuff.

Let me clarify, I never add any salts to my stripping runs rather only in the final spirit run to knock down on the esters and lower aqueous volatility. I really have no experience with copper, as I've always went with glass and stainless for their chemical resistance.

I am building a new copper still I will have to be careful not to take that for granted.

[Bagasso]

I would like to say that I have used sodium hydroxide in my last 7 or so batches. I use about 3 grams per liter of wash. This has given me a ph of 7.2 to 7.4. Let sit for a couple of hours. I get a layer of fluff at the bottom which I leave behind when I siphon my wash into the boiler. Pot is SS with about 4 inch copper riser and copper coil in a bucket. I have not gotten any blue distillate. I know that some have when using baking soda. Might have something to do with the chemical make up of the alkili and not the ph. I did strip a wash with a ph of 8.4 and also no blue not even the slightest hint.

[mrhooch]

Well the blues apparently happen when you add DAP Di Ammonium Phosphate (NH4)2HPO4 as a nitrogen boost. In akaline environments it will decompose to ammonia gas. It was a FML moment.

Hooch.

[Bagasso]

I have noticed a bit of blue, so slight that I had to hold up to a lamp to confirm, when using Baking soda in low wines stripped from a wash with no DAP. Don't know what caused it but the only thing different from my other runs was the baking soda.

[mrhooch]

Well if it is what happened to you, there will be a very distinct ammonia smell!!!!

Hooch.

[Bagasso]

No, what I was talking about in my previous post was baking soda in stripped low wines and it was such a light hint of blue that I probably only noticed it because of a table lamp I had across the table. No smells other than the norm. The wash that I had stripped, before adding the baking soda, had not had any DAP. Just sugar, water, wheat germ, boiled yeast slurry and yeast.

That's what makes me think that it's the chemical and not the ph cause one wash with sodium hydroxide got up to ph8.4 and had no ammonia smell or blue distillate.

[ScottishBoy]

ScottishBoy, Sodium Carbonate or bicarbonate?

Carbonate. Sorry for the delay. That was my vacation week...first one in 6 years...