cheap DIY pressure cooker still, rubbery taste

[cyrusvalkonen]

So I have connected a pressure cooker to a hot water kitchen faucet hose which connects to a copper condenser spiral.

In my test run with water, I noticed that the water coming out of the condenser, as well as the water that is still inside the pressure cooker, both have a slight rubbery taste to it. If mixed with ethanol, juice or food, you wouldn't even notice it.

The pressure cooker has a huge rubber gasket in it like usual, and the hose is made of rubber or plastic as well.

The source of the rubbery taste seem to be both the gasket as well as maybe the hose. Since the taste at the outlet seems to be somewhat stronger than what the water tastes inside the pressure cooker.

Concerning safety of the materials, obviously the pressure cooker rubber gasket should be by design food-safe. Concerning the faucet hose there also should be no real safety concern, as it runs only 20-30C above max design temperature with water and inside design temperature with alcohol. Plus it is made for drinking water.

I know quite a bit about plastics, and insofar as that the manufacturers did use proper components (silicone rubber, NBR, PEX, EPDM), neither running slightly above design temperature nor running alcohol instead of water produces any noteworthy health concerns due to leaching and such. Even more so considering the small quantities that you consume alcohol in.

I do not want to advertize my setup as good. It was just the absolutely cheapest way to do it ($14), ostensibly in a safe enough manner.

I know this forum has an anti-plastics rule. However, considering that the pressure cooker itself (which is made for food, including stews with wine and such) produces this taste, I think it is appropriate to ask whether or not this is a phenomenon that always occurs whenever any sort of plastics are used, and if going all copper is the only way to produce a distillate with pure taste. Obviously so, foodstuff can be much much more chemically reactive and corrosive than pure ethanol, due to acidity mainly but also diversity of chemicals.

Also I want to ask if copper solder and flux residue will have a slight effect on taste in pure water as well. After all, even just miniscule chemical reactions can change the taste of water. It is also true that mixing stainless steel with copper causes electron migration and consequently corrosion, which releases chemicals from the metal. Stainless steel cooking ware usually has extremely high nickel and chromium parts in it (20%), which I imagine can alter the taste in pure water test runs as well and has very similarly minor health concerns attached to it, compared to appropriate plastic materials.

Have you done tap water taste tests with your metal still? Be that pure copper or mixed metals.

Has anyone experience with rubber gaskets and hoses for hot drinking water?

I also wonder if there is something wrong with my pressure cooker gasket or hose, or if this is basically "just normal".

[jonnys_spirit]

TLDR;

I did read plastic, pressure cooker, and still. These things together are a really bad idea.

If you’re really interested do some reading and research and please be highly observant of the site rules which you also mentioned.

Good luck!
-jonny

[cyrusvalkonen]

Most questions raised are about slight taste alterations with pure water test runs, irrespective of plastic use.

[Wildcats]

STOP!!!! Really???? Do you want to drink the sh&@t??? You need to scrap that whole idea. There is no rubber in a still!!! Just because you think it's ok, doesn't mean it is. I suggest you do more research before you go any further.

[cyrusvalkonen]

I understand that there are safety concerns with plastics. For example a lot of microwave ware, baby bottles and plastic water cookers were made with Bisphenol A in the past, an extremely potent endocrine disruptor active in the microgram range that leaches especially if the polymer is exposed to heat and/or acid (e.g. tomato sauce).

As such, there are certain unknowns when using pressure cookers with rubber gaskets to cook food or water with.

However while this might be the case, I think we can reach a consensus here that materials designated as food-safe inside design temperatures are to be considered low toxic hazards that people generally think of as safe to use.

[Wildcats]

I understand that there are safety concerns with plastics. For example a lot of microwave ware, baby bottles and plastic water cookers were made with Bisphenol A in the past, an extremely potent endocrine disruptor active in the microgram range that leaches especially if the polymer is exposed to heat and/or acid (e.g. tomato sauce).

As such, there are certain unknowns when using pressure cookers with rubber gaskets to cook food or water with.

However while this might be the case, I think we can reach a consensus here that materials designated as food-safe inside design temperatures are to be considered low toxic hazards that people generally think of as safe to use.

Food grade and food safe plastic are not safe with high temperature high proof alcohol vapor. And it is in the rules here on HD. We don't even consider silicone safe. What you do in your shed is on you. But here we use only ptfe. Any rubber in the vapor path is gonna leach out potentially toxic substances. He takes safety very serious here on HD. We want you to be safe.
Grab you some copper tubing and replace the dishwasher hose....and make you a ptfe gasket. At least..
Good luck and stay safe man.

[Salt Must Flow]

The rubber gasket is absolutely a no go. Same for the hose. If it's an aluminum pressure cooker then that's bad too.

[cyrusvalkonen]

Well, all plastics always leach chemicals. The main two components that acellerate it being heat and acid. Acetic acid (vinegar) for example is generally speaking much more potent to facilitate this than alcohol is, although different plastics may react differently.

What is most important with leaching are the kind of additives used in plastic and what contaminants it might have. This is mainly a matter of what type of plastic you are dealing with, less so how you use it. Hence it is foremost a matter of what the materials were intended for, and only on top of that you have to consider accelerated release through heat and then chemical reactivity.

Foods contain all kinds of different acids. Tomato sauce for example has been shown to be much much more potent to leach nickel out of frying pans than vinegar alone. Up to the point where dangerous levels of nickel can be achieved when cooking tomato sauce with onions.

There is a lot of science on this topic, but obviously it also leaves a lot of gaps to reach certainty in some areas.

As a rule of thumb though, acids trump alcohol and certain foodstuff can be extremely reactive, much more than pure alcohol.

Personally speaking, I never buy vinegar in plastic bottles. And also there is a lot of concern now about regular food packaging, because in the EU manufacturers have been exempt from liability recently, if it comes to the use of recycled plastics. Thus plastics in food packaging might now be recycled 100x in the row, each time it enriches additives and contaminants. And you don't even know what waste sources are part of the recycling chain. Before, only pristine plastics were used, which was much safer.

So I agree that plastics suck in a lot of ways and are not always as safe as sold.

I also wouldn't use that pressure cooker I have for food, now that I know that it causes water inside to taste rubbery. Just common sense and being cautious.

However, one also has to admit that alcohol is quite toxic on its own and only sparsely consumed in small quantities. So its a little bit out of perspective to think of a vodka bottle as healthy, because it is made out of glass and not plastic. Having just one sip more will probably be 50x worse than whatever leaching from plastics might be in there.


I am glad though I build this $14 still as a starter project. Because I have just done a test run with my wine, and it literally just tastes like rubbing alcohol mixed with distilled water. It surely is safe enough for a good taste test and to get familiar with the whole process. Had I invested in proper equipment, it would have been a huge waste and disappointment.

I thought there would be much much more flavor to the destillate. But there is no flavor at all. It has less flavor than vodka. The yield is also quite small. Like expected, the rubbery taste is impossible to notice with real alcohol.

I don't think I will be distilling much in the future.

I would be very interested though, if you could answer my questions about taste alterations with your distille, if distilling pure water.

[cyrusvalkonen]

The rubber gasket is absolutely a no go. Same for the hose. If it's an aluminum pressure cooker then that's bad too.

Aluminium is always bad, since it is a potent neurotoxin. Cooking ware should never be made out of aluminium.

[Deplorable]

Let me grab my popcorn before this discussion gets locked...
BRB

[Wildcats]

Let me grab my popcorn before this discussion gets locked...
BRB

Rite. At least it'll get moved to " what not to do" thread.

[Setsumi]

Let me grab my popcorn before this discussion gets locked...
BRB

Best answer yet. Why does anyone respond....? Stoopid does what stoopid do.