Rotary evaporator

[Sparren]

Hi,

Time to wake this sleeping thread up. I have ordered a Heidolph Rotary Evaporator with vacuum pump but no chiller.

Will running tap water through the condensor coil be sufficent for most culinary applications or do I need a chiller?

I have two options for chillers in mind. Lauda MC 250 which is cheaper but only goes to -10 or Heidolph RotaChill large that goes to -20.

With the later one I also risk blowing fuses if i run everything on the same fuse.

I would also appreciate some recipes/ideas for what to try in the rotavap. (I have read most stuff in this forum and other resources that google leads me to like cookingissuses)

[HungryChris]

I just don't get what the attraction is to a rotovap. What is it that you intend to do with this thing that is going to make your life so much better? I used to work in a lab that had a big rotovap that used a water aspirated vacuum system for the vacuum and a large and bulky water bath for heat. it was never anything I would want in my kitchen and took up more than half the counter space that  I now have. What do you intend to do with it?

HC

.  

[Sparren]

1 hour ago, HungryChris said:

I just don't get what the attraction is to a rotovap. What is it that you intend to do with this thing that is going to make your life so much better? I used to work in a lab that had a big rotovap that used a water aspirated vacuum system for the vacuum and a large and bulky water bath for heat. it was never anything I would want in my kitchen and took up more than half the counter space that  I now have. What do you intend to do with it?

HC

.  

 

I'm a fan of modernist cuisine in love to experiment. What I have been missing in my kitchen is to perform reduction without adding heat and therefore altering flavours. Also extracting flavours sounds very interesting. I realise a Rotavap isn't for everyone but for me cooking and experimenting in the kitchen is my biggest hobby so I spend lots of money in the kitchen. Yes I lack counterspace in the kitchen so the rotavap may end up in the laundry room.

Edited April 14, 2016 by Sparren (log)

[paulraphael]

15 hours ago, HungryChris said:

I just don't get what the attraction is to a rotovap.

 

 

It can produce flavors that aren't possible by any other culinary method. You can get distillates, like brandies, with more vibrant flavors than what you get from traditional methods. And the stuff left behind after distilling is often a delicious syrup, one that has no culinary precedent and that can't be obtained other ways. This is just the beginning of what's possible. 

 

And no, I don't have one. It's just easy for me to see the appeal.

Edited April 14, 2016 by paulraphael (log)

[Duvel]

if you are interested in the destillates, tap water as the cooling medium will most likely insufficient.

If you let me know the specs of your vacuum pump and your desired application ( reduction of water-based solutions, alcohol etc.) I can give you an definite answer ...

[HungryChris]

4 hours ago, paulraphael said:

 

It can produce flavors that aren't possible by any other culinary method. You can get distillates, like brandies, with more vibrant flavors than what you get from traditional methods. And the stuff left behind after distilling is often a delicious syrup, one that has no culinary precedent and that can't be obtained other ways. This is just the beginning of what's possible. 

 

And no, I don't have one. It's just easy for me to see the appeal.

As someone who has used these things for years, I am more than familiar with the theory behind what they can do and what they can be used for. The fact remains that they are research tools. While they may produce flavors that are significant, using them to produce something beyond a 300 mg sample that you can impress your friends with, is just not there. The fact that you may be able to produce a blood orange flavor that you are proud of and can offer your friend a taste of, in my mind, just does not justify the expenditure,  space, round bottomed flask collection and storage needs they require. The fact remains that if you discover something that you find worth pursuing, you must either work round the clock or find a way to scale up it's production.

HC

[paulraphael]

1 hour ago, HungryChris said:

As someone who has used these things for years, I am more than familiar with the theory behind what they can do and what they can be used for. The fact remains that they are research tools. While they may produce flavors that are significant, using them to produce something beyond a 300 mg sample that you can impress your friends with, is just not there. The fact that you may be able to produce a blood orange flavor that you are proud of and can offer your friend a taste of, in my mind, just does not justify the expenditure,  space, round bottomed flask collection and storage needs they require. The fact remains that if you discover something that you find worth pursuing, you must either work round the clock or find a way to scale up it's production.

HC

 

I'm not trying to sell you on one; I haven't sold my self on one either (for many of the reasons you mention).

 

But I don't see how they're suitable only for research. They're in use in quite a few professional kitchens, bubbling out concoctions for paying guests. Batch sizes are way beyond 300mg. Check out the rotavap section on the Cooking Issues site, which includes recipes. The Modernist Cuisine series has an in-depth section also. Its recipes have yields between 180g and 1.5kg. 

[Sparren]

15 hours ago, Duvel said:

if you are interested in the destillates, tap water as the cooling medium will most likely insufficient.

If you let me know the specs of your vacuum pump and your desired application ( reduction of water-based solutions, alcohol etc.) I can give you an definite answer ...

 

My Vacuum pump is Heidolph Rotavac Vario Control capable of 1,7 m3/h ant my tap water is 10c.
I would like to do both reduction and distillates of both water based and alcohol based products. Yesterday i tried with apple juice. The reduction turned out good but the distillate tasted to watery.
Now I'm trying to make a distillate of alcohol and black pepper. At the moment parameters are 44c water bath and 150mbar pressure. I started with 30c in the bath but either I was not patient enough or it was to low compared to the 10c coolant. I'm just guessing since i'm new with this.

[adey73]

keep it coming Sparren!!

 

am very interested!

[rotuts]

 

@Sparren

 

very very cool !

 

all I could google is this :

 

Heidolph Rotavac Vario Control

 

I love it !

 

lottery is coming up, Ill get a ticket !

 

which is your Vac ?

 

nice

 

congratulations !

[Sparren]

Yes that is the vacuum pump and it's integrated with the rotary evaporator (Hei Vap Precision) for easier control. This is more advanced equipment then I opted for but I got a good price on a demo unit.

Black pepper is spinning at the moment. After that i will try pomegranate, tomatoes, habaneros, jalapenos and blood oranges.

 

[Duvel]

22 hours ago, Sparren said:

 

My Vacuum pump is Heidolph Rotavac Vario Control capable of 1,7 m3/h ant my tap water is 10c.
I would like to do both reduction and distillates of both water based and alcohol based products. Yesterday i tried with apple juice. The reduction turned out good but the distillate tasted to watery.
Now I'm trying to make a distillate of alcohol and black pepper. At the moment parameters are 44c water bath and 150mbar pressure. I started with 30c in the bath but either I was not patient enough or it was to low compared to the 10c coolant. I'm just guessing since i'm new with this.

At 150 mbar the boiling point of water is around 55 oC. As you are using a rotor vap - essentially a thin-film evaporator - you can get significant amounts of liquid into the gas phase at lower temperatures. You might raise the temp by a couple of degrees, but if your cooling medium is only 10 oC that would lead to higher losses. If your vacuum pump has a liquid separator (it should) you will find that at 10 oC cooling medium (really ?) you may condense about 80 percent, given a proper design of the cooling section. Much lower you can't get: once your cooling medium drops below 0 oC you will get solidification of the aqueous distillate. To achieve higher condensation rates you might increase the pressure (doubling it will give you 10 oC more in boiling point). You want to aim for a 50 oC differential between boiling point and cooling medium to get around 90plus percent condensation. It will improve also the "trapping" of flavours in the distillate.

 

 

[paulraphael]

31 minutes ago, Duvel said:

At 150 mbar the boiling point of water is around 55 oC. As you are using a rotor vap - essentially a thin-film evaporator - you can get significant amounts of liquid into the gas phase at lower temperatures. You might raise the temp by a couple of degrees, but if your cooling medium is only 10 oC that would lead to higher losses. If your vacuum pump has a liquid separator (it should) you will find that at 10 oC cooling medium (really ?) you may condense about 80 percent, given a proper design of the cooling section. Much lower you can't get: once your cooling medium drops below 0 oC you will get solidification of the aqueous distillate. To achieve higher condensation rates you might increase the pressure (doubling it will give you 10 oC more in boiling point). You want to aim for a 50 oC differential between boiling point and cooling medium to get around 90plus percent condensation. It will improve also the "trapping" of flavours in the distillate.

 

 

 

Just push the AUTOeasy button.

 

[Duvel]

11 minutes ago, paulraphael said:

 

Just push the AUTOeasy button.

 

That only works out if you are interested in getting quick access to the residue. If you want to isolate all or most of the distillate you might need a tiny bit more thought ...

[paulraphael]

I just like that this sci-fi looking piece of lab kit has a button marked AUTOeasy.

It's like seeing that label on a time machine or a doomsday device.

[Sparren]

I tried the auto easy button but not much happened. Pressure stabilized at around 800mb but nothing ended up in the recieving flask. This may be beacuse i have not recieved the optional temp sensor yet or that the cooling liquid is to warm (+10c).

I will order a cooling unit but would appreciate some advice. The Lauda MC 250 goes down to -10 and the Heidolph Rotachill Large goes to -20c but is much more expensive. Will the Lauda limit my culinary applications?

[Sparren]

1 hour ago, Duvel said:

That only works out if you are interested in getting quick access to the residue. If you want to isolate all or most of the distillate you might need a tiny bit more thought ...

 

Are you working at a lab? You seem to have lots of knowledge in this kind of equipment. Thanks for sharing your knowledge.

[adey73]

Any chance of a photo of the whole rig? 

[Duvel]

12 hours ago, Sparren said:

 

Are you working at a lab? You seem to have lots of knowledge in this kind of equipment. Thanks for sharing your knowledge.

I used to - fun times.

 

For your decision making for a chilling unit: i think that more than the minimum temperature of your coolant your focus should be on the overall cooling capacity per hour - the more stable your coolant temperature, the more and faster you can condense and the higher your yield. 

 

When you say alcoholic black pepper reduction: could you share the proportions ? Which type of alcohol you use (percentages, source) ?

[Sparren]

This is the setup. I'm not sure of the proportions, I just throwed a handful of black pepper corns into 40% vodka from the liquor store and let it run. I kept both the distillate and reduction (filtered) and both held nice flavours. I was surprised that the reduction was not hot compared to the runs with chilli where the reduction was super hot.
Now blood orange juice reduction.

 

[paulraphael]

Envy. That is one helluva crockpot.

[adey73]

did you recombine the distillate and the reduction? ...Dave Arnold insists that chillies have a fantastic floral flavour with out the heat.

 

(I tried to buy an ex-display Buchi in the UK, but they wouldn't let me once I'd stupidly admitted food use)

[Sparren]

On 2016-04-18 at 1:27 PM, adey73 said:

did you recombine the distillate and the reduction? ...Dave Arnold insists that chillies have a fantastic floral flavour with out the heat.

 

(I tried to buy an ex-display Buchi in the UK, but they wouldn't let me once I'd stupidly admitted food use)

 

I kept the reduction and the distillate apart. He´s right, the capsacin stays in the reduction and makes it extremely hot. The distillate has very nice flavours and I have used it in cocktails. A habanero cocktail without the heat is delicious.
I'm surprised the refuse to sell you one since you can order them online both in UK and Sweden.   

[paulraphael]

 

6 hours ago, Sparren said:

A habanero cocktail without the heat is delicious.
 

I had habaneros once that were grown oddly (maybe too much water?) and had virtually no heat. Fantastically delicious.

Super cool that you can basically deconstruct a chili and use the various components separately.

[Sparren]

On 2016-04-16 at 3:52 PM, Duvel said:

At 150 mbar the boiling point of water is around 55 oC. As you are using a rotor vap - essentially a thin-film evaporator - you can get significant amounts of liquid into the gas phase at lower temperatures. You might raise the temp by a couple of degrees, but if your cooling medium is only 10 oC that would lead to higher losses. If your vacuum pump has a liquid separator (it should) you will find that at 10 oC cooling medium (really ?) you may condense about 80 percent, given a proper design of the cooling section. Much lower you can't get: once your cooling medium drops below 0 oC you will get solidification of the aqueous distillate. To achieve higher condensation rates you might increase the pressure (doubling it will give you 10 oC more in boiling point). You want to aim for a 50 oC differential between boiling point and cooling medium to get around 90plus percent condensation. It will improve also the "trapping" of flavours in the distillate.

 

 

 

The Lauda MC250 is able to provide cooling medium at -10. To me that sounds good enough. I have read that the temperature difference between the water bath and the cooling liquid should be at least 40c.
If I understand things correctly that means a will have a decent yield with whater bath temperature of 30c and above as long as the Lauda cooler is able to hold -10c.
The specification says it´s cooling capacity at -10c is 90w but I'm not sure how to calculate if that is enough?