What difference does the shape of the boiler lid make?

[wombatvvv]

I was just watching a YouTube video on making a pot still. The guy was using a pressure cooker with a flat lid. He mentioned because the lid was not domed, it was only suitable for distilling basic sugar wash and the like. Seriously? What difference does the shape of the lid make?

What about the thickness of the pipe coming out of the lid? Would it be best to use a 2" copper pipe connected to a mixing bowl for a lid? Or does the pipe thickness not matter? I ask only because I've been watching some doccos on professional distilling, and noted that their pot stills are basically huge cones. The only way I could think to emulate that is with a very thick pipe coming out of a mixing bowl.

Not that I'm planning on distilling high quality single malt. lol. I'm just curious. I may as well build the best thing I can.

As always, sorry if my questions are stupid. I'm too much of a newb to know what's stupid and what's not. Or even what to search for in order to find out.

Much appreciation for your time.

Vic.

[Soggy Bottom Boy]

A high domed lid allows for a little extra headroom for foaming and boiling action so you don't puke up the riser and out the condenser. Just don't fill the pot too full or boil too hard, and Bob's your uncle!

[zaph1]

I've wondered the same and hope someone with a good explanation will chime in. It seems to me that a gas under pressure will find the opening whether there's a funnel to it or not. There's a bit of logic to a larger take-off and the extra room for boiling, but the dome or funnel shouldn't make a difference over a flat lid. Boyle's Law, pV=k, covers the physics of expanding gases.

[BoomTown]

makes me wonder if there might be more 'reflux' kind of activity in a domed lid vrs a flat lid?

[Lucent]

Basic physics tells you that the size of the collection pipe should be concurrent with the size of the pot that's greeting the gases. Sure the expanding gases will find the quickest route out but if that tube is too small and the route causes too much back pressure to build up the only place it has to go is, boom!

The domed or conical lids make sense for the providing more space as well as surface area and directional encouragement I would think it would be better to have more room for the gas to rise above the distillate in the boiler as it makes its way towards the exit. From what I've read washes have a habit of expanding during the distillation process so it's good to have more room.

Just my thoughts on the subject. I've been thinking about the same and I yet again slammed the breaks on my still build because I'm not sure the beer keg I have is going to give me the ideal shape I need for my boiler so I'm also investigating other possibilities instead of just rushing forward with that part of the build


Luc-

[Prairiepiss]

I personaly think the guy you sleek of doesn't know his ass from a hole in the ground. His statement is unfounded and just plain ignorant.

It can make a difference. Not as noticeable on something as small as a pressure cooker.
The added head room of a domed top. Is helpful for a foamy wash. And a little better separation. But a flatter lid can be used quit effectively if used proper.

If you are feeding a small tube from it. You will have a slower production rate. In the fact that all vapors will want to move out through that small tube. And will actually be pushed into the tube with little of no time to separate further. A larger tube or riser will give an area with less vapor speed for a better separation of different vapors. So it will allow for a faster take off rate. Not necessarily reflux action. But more like better vapor manipulation. Yes there will be more surface area that could create more natural reflux. But once a still of this size gets up to temp. With out forcing reflux. It will be kept to a minimum by all the heat created in the smaller space.

The shape of a still really only makes a big difference on very large stills. And doesn't really dictate what should be ran through it. The type of still will however dictate what is best to run through it. And what has been described is a pot still. So the best things to run through it would be rums, whiskeys, and brandys. Actual sugar washes are usually intended for a neutral product. Which is best ran through a reflux still. It can be ran through a pot still. But its not best suited for it.

Also note sugar wash and sugarhead wash are two different things. One is intended for a neutral and the other a flavored faux drink.
Examples.
Birdwatchers is a sugar wash intended for a clean neutral. And is best suited for a reflux still. Yes it will work in a pot still.
UJSSM is a sugarhead intended for a faux whiskey. And is best suited to be ran in a pot still or the like. Something to bring out the flavors created with the recipe.

[BoomTown]

Hey P., you open of a whole new can of worms here. What do you mean by "faux" whiskey? Isn't what we are getting using a sugar head 'real' whiskey?

Boom

[Prairiepiss]

No a real whiskey is made from grains only. No sugar added. And no can of worms.

Sory will add.

Legally a whiskey is made from a ferment that was made from mashing grains only.
By adding sugar to a grain you are not fermenting the sugars created from the mashing process. You are fermenting the sugar you add. And only getting some flavors from the grains. By legal standards I know of nothing a sugarhead could be called? Rum is made from sugar cane. But doesn't include anything else. So I'm not sure you could call it a rum. Brandy is a fruit and no fruit in it. Vodka can be made from anything that will ferment. But it has to come off at 95% ABV or higher. In the US anyway. So it can't be a vodka unless you are taking it off at 95% or higher. And that would kinda defeat the purpose of a flavored sugarhead.

I'm not to sure of the definitions of schnapps and liquors? But I doubt it could be called either of them.

[Dnderhead]

"
"I'm not to sure of the definitions of schnapps and liquors"
schnapps,the real stuff (German) is made from all fruit much like brandy ,left in the "white",,in US its usually flavored neutral.
"real"brandy is made from grapes.Much of the US "fruit" brandy is grape brandy flavored.
I believe liquors can be made of anything ,then flavored/and usually sweetened.
so id say ,much of the US."fruit brandy" "schnapps" "flavored vodka" is really "liquors"
so it gits a bit confusing.

[Prairiepiss]

I have been wondering really hard lately how they can call all these flavored vodkas vodka. I would consider them more of a liquor then a vodka.

And yes the US definition of these are a little cornfusing.

So Dnderhead what would you think a sugarhead would be called? Or could be called?

Damn we are getting off topic here. Sory.

[Dnderhead]

"So Dnderhead what would you think a sugarhead would be called? Or could be called? "
they really don't fit but maybe
moonshine/sugar head or flavored rum? on ADI we called it "rumskey"
like "sweet feed" is really rum as your fermenting the sugar/molasses not the grain.
so its a "grain flavored" rum,, thus "rum-skey"???

[wombatvvv]

Interesting discussion, although strayed a little off the original topic.

Personally, I just call it all "moonshine".

That is of course, unless it's entirely made with grain, which I don't plan on attempting any time soon. I have to actually build a still first.

[ChefSteve]

If you lookt around the web under this or just pic. you will see big domrd tops and flat tops you need to read about deferent countries and coustoms and you will see they all make and drink something that they made read read read you will learn alot on the subject that we all have an intrest in. Did I READ you bet cha