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Posted

Hey all, was browsing the web and wanted to try this out. Just don't quite understand why you have the hotplate? Is the vacuum not strong enough?

Posted

@cazzueyEvaporation is a cooling process, so while the liquid may start at room temperature, as it "boils", it will lose heat and will get colder and colder... so the hotplate is used to keep it "warm"

Posted (edited)
56 minutes ago, KennethT said:

@cazzueyEvaporation is a cooling process, so while the liquid may start at room temperature, as it "boils", it will lose heat and will get colder and colder... so the hotplate is used to keep it "warm"

 

I see, very interesting @KennethT. Also, is an average flask strong enough to make this experiment safe from risk of implosion?

Edited by cazzuey (log)
Posted

I don't have personal experience with it, but I would imagine that a standard Pyrex flask should be just fine - I imagine the seal on the rubber stopper would probably break before the flask does, unless there's a preexisting chip or crack.

  • 2 years later...
Posted
On 8.9.2014 at 4:28 PM, DiggingDogFarm said:

FWIW, it is possible to do vacuum reduction without a magnetic stirrer/hot plate if anyone happens to want to try this on the cheap.

This link is dead. The information can be found here: https://www.chefsteps.com/forum/posts/vacuum-reduction-3

 

If you don't have a stirring plate Chris Young recommends to add boiling stones to your flask to provide more nucleation sites.

  • 8 months later...
Posted (edited)

After reading about vacuum concentrating I wanted to try it out. I'm currently in the process of building a setup for it on the cheap.

My current setup is the following an aspirator connected to pump that circulates ice water. The aspirator is then connected to a vacuum flask on the stove.

setup.thumb.jpg.6f2b447c88eedbcdb798e6a0460c3987.jpg

 

There are some issues that I cannot fully solve. First the suction of the aspirator is variable based on position and if the line back to the ice bath is under water or not. But a vacuum is definitely created. 

@DiggingDogFarm is there something wrong with my circulation setup?

 

The second is that my water got way over 70°C even with an ice water bath. It might be that my stove top was at a too high temperature. I'll make a new test run next weekend to rule this out.

To test my vacuum I ordered a vacuum gauge to test is my aspirator is even working as intended.

 

I hope to get this project working because it would be nice if there was a way to make vacuum concentrations at home without spending a lot of money.

Edited by THS (log)
Posted
3 hours ago, THS said:

@DiggingDogFarm is there something wrong with my circulation setup?

 

You may want to try a faucet powered aspirator for better consistency.

  • Like 2

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

Posted

I don’t understand how this works. Is the thing you are concentrating in the flask? Looks more like distillation to me. 

For temp control I’d use a Sous Vide machine. 

Posted
37 minutes ago, gfweb said:

I don’t understand how this works. Is the thing you are concentrating in the flask? Looks more like distillation to me. 

For temp control I’d use a Sous Vide machine. 

 

The process is detailed in Modernist Cuisine.

Here, Chris Young answered one of my questions a few years ago... https://www.chefsteps.com/forum/posts/vacuum-reduction-3

  • Like 1

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

Posted

FWIW, faucet powered aspirators and medical aspirators are generally considered the safest.

But medical aspirators can be quite expensive!

In the following post I PROVE  that a $25 faucet aspirator is just as good at compressing as an $850 chamber vacuum sealer—AFTER someone told me is wasn't possible!..

https://forums.egullet.org/topic/150195-compressedmarinated-fruit-sans-chamber-sealer/?do=findComment&comment=1999100

 

  • Like 3

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

Posted
19 minutes ago, DiggingDogFarm said:

Looks more like distillation to me. 

 

In a nutshell, the result is similar to that of a very expensive rotovap.

  • Like 1

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

Posted
7 minutes ago, DiggingDogFarm said:

FWIW, faucet powered aspirators and medical aspirators are generally considered the safest.

But medical aspirators can be quite expensive!

In the following post I PROVE  that a $25 faucet aspirator is just as good at compressing as an $850 chamber vacuum sealer—AFTER someone told me is wasn't possible!..

https://forums.egullet.org/topic/150195-compressedmarinated-fruit-sans-chamber-sealer/?do=findComment&comment=1999100

 

I've done this with a faucet aspirator also - the biggest problem with it is the huge use of water.

  • Like 1
Posted
1 minute ago, KennethT said:

...the biggest problem with it is the huge use of water.

 

It can be—I created a recirculating set-up to solve that problem and to make the water extremely cold!

But, It's been a long time since I've messed with any of it!

I've turned extremely lazy! xD

If one gardens, the "waste water" could also be diverted to that—or the washing machine.

I've done both.

 

 

  • Like 3

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

Posted
11 hours ago, DiggingDogFarm said:

 

You may want to try a faucet powered aspirator for better consistency.

I have currently a cheap aspirator from Aliexpress in use. I'll try to connect it to a faucet.

I found a post here that is aspirator might not be that good: http://www.sciencemadness.org/talk/viewthread.php?tid=103724#pid552556

 

4 hours ago, DiggingDogFarm said:

FWIW, faucet powered aspirators and medical aspirators are generally considered the safest.

 

I found another really cheap aspirator on Ebay. I bought it to test if this one is better. If both fail me, I'll buy a more expensive one from a lab supplier.

Is there a noticeable  difference between the metal one from Humbolt and the plastic one from Brand? 

 

For the circulation I currently use a 12v diaphragm water pump and I have a 12v solar pump lying around that I could try.

Posted

When I was a quondam biochemist a faucet aspirator was the thing to use.

 

  • Like 3

Cooking is cool.  And kitchen gear is even cooler.  -- Chad Ward

Whatever you crave, there's a dumpling for you. -- Hsiao-Ching Chou

Posted
56 minutes ago, THS said:

Is there a noticeable  difference between the metal one from Humbolt and the plastic one from Brand? 

 

The only difference is probably durability.

The metal aspirators should be more durable.

But, I haven't had a durability problem with the "Brand."

 

So—a faucet aspirator, powered by very cold water—and a vacuum leak check of the system.

That should get you off to a good start. 

  • Like 2

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

Posted

@THS I believe that the Dynalon 312635 is exactly the same as the faucet aspirator that I have.

https://www.ebay.de/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Dynalon+312635&_sacat=0

 

  • Like 1

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

Posted

Here are some updates. I finally got something working!  The new aspirator and connecting it directly to a faucet did the trick.

The water temperature on my faucet is 13°C and with the created vacuum I could get water to boil at 60°C, which is quite an improvement.

 

My vacuum gauge was most of the time fully maxed out when I tested the aspirator.

aspirator-setup.thumb.jpg.e8b6c0346dbcabaab08e38d515c27b96.jpgvacuum.thumb.jpg.7aff6cbec0ea411999342bef4ee0f14f.jpg

 

Water is boiling!

water-boiling.thumb.jpg.c3ab5e0595d0a8e3d72e558a0b1c7582.jpg

 

 

  • Like 3
Posted

Next steps are to build a circulation setup with the new aspirator and trying it with ice water.

My Goal is to get under 40°C for concentrating. Next weekend I'll try a different liquid than water to see if foaming is an issue that has to be resolved.

  • Like 2
Posted

@THS Cool! cool.gif

~Martin :)

I just don't want to look back and think "I could have eaten that."

Unsupervised, rebellious, radical agrarian experimenter, minimalist penny-pincher, and adventurous cook. Crotchety, cantankerous, terse curmudgeon, non-conformist, and contrarian who questions everything!

The best thing about a vegetable garden is all the meat you can hunt and trap out of it!

 

  • 2 months later...
Posted

Small  update: I rebuild my recirculation setup with  the new aspirator and it's only pulling a -0.5 bar vacuum instead of nearly -1.0 bar when it's directly connected to the faucet.

 

I want to get this project fully working but I'll have to look into getting another pump to build a nice setup, because connecting it directly to the faucet is wasting to much water.

  • Like 1
Posted (edited)

what about using a degassing chamber used for silicone rather than the pyrex lab glass?

 

this has always interested me, please add more photos when you've achieved the new set up.

 

Edited by adey73 (log)
  • Like 1
Posted
6 hours ago, adey73 said:

what about using a degassing chamber used for silicone rather than the pyrex lab glass?

This should theoretically work, but I used the Modernist Cuisine Post and they have their flask on a hotplate with a magnetic stirrer.

 

I'll post updates when I get new results. The pump upgrade has unfortunately wait for a few months because I have some other kitchen experiments that are costing me money.

I currently cannot justify to spend 50-100€ more on this project after the previous failed attempts. 

 

@adey73 If you want to get started don't make the same mistakes I made.

First buy an used lab aspirator on ebay (or similar) and test it with a vacuum gauge on your faucet and then try to build a more complex system.

 

Posted (edited)

@THS if you were to start over again, what specifically would you buy?

 

And how do you measure the temperature of the fluid inside the vessel you’re seeking to reduce? 

Edited by adey73 (log)
  • 10 months later...
Posted

So I've been reading and re-reading the section in Modernist Cuisine on vacuum concentration.  Seems like a really powerful idea, but even MC does not contain sample recipes for this (that I can find).  There are a handful of rotovap recipes a few pages later, but no vacuum concentration.  (BTW, hard to believe MC is 9 years old now.  Doesn't look like this technique has caught on in all this time).

 

Concentrating citrus or other acidic juices seems kind of neat, but not life-changing enough for me to buy the equipment.  Has anyone concentrated stocks or consommes?

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