Centrifuges

[lancastermike]

It is a well know fact that i am not very enlightened in the modernist ways. I hesitate to ask. Of what purpose would a centrifuge of the kind being discussed here serve the average home cook? I mean, what am I supposed to be separating?

My apologies to all for being such a dunce.

Mike,

I became interested in rigging a centrifuge when I read about Nathan Myrvold's pea butter. He centrifuged pureed peas into water, fibrous starchy solid and pea "butter". He used this lipid layer on crustini and said it was delicious. I believe him. If I can rig a strong enough spinner to get this kind of separation out of stuff I already have, well then buy me a new dress and call me Rube Goldberg, it'll be a good day.

If I go to my grave and never had the ability to make pea butter in my kitchen I think I will be fine with that. And BTW Rube Goldberg was a guy, Reuben Lucius Goldberg to be exact.

Edited February 23, 2011 by lancastermike (log)

[Paul Kierstead]

If I go to my grave and never had the ability to make pea butter in my kitchen I think I will be fine with that.

Well, no one was exactly demanding that you do so....

[Chris Hennes]

Modernist Cuisine's section on centrifuges is pretty short, but the recipes it lists are:

• How to separate fresh butterfat from cream
  
• Carotene butter
  
• Tomato water
  
• Pea juice (including pea butter)
  
• Roasted hazelnut oil
  

In addition, in volume five the centrifuge makes a few (optional) appearances, where it seems to be used mostly for clarification. I'd bet you could develop an entire cookbook based on neat things you can do with a centrifuge... if only anyone but Nathan and the guys at Cooking Issues had one!

[JBailey]

As I have inquired earlier, are there particular models, sizes or types of centrifuges we should seek for food experiments? Also, I appreciated some of the warnings of things and types of machines to avoid. Like circulators bought surplus, you may never know where they have been, what prior chemicals they were used with or how well treated they were.

[Chris Hennes]

You might want to have a look at the Cooking Issues post on centrifuges in the kitchen.

[runwestierun]

It is a well know fact that i am not very enlightened in the modernist ways. I hesitate to ask. Of what purpose would a centrifuge of the kind being discussed here serve the average home cook? I mean, what am I supposed to be separating?

My apologies to all for being such a dunce.

Mike,

I became interested in rigging a centrifuge when I read about Nathan Myrvold's pea butter. He centrifuged pureed peas into water, fibrous starchy solid and pea "butter". He used this lipid layer on crustini and said it was delicious. I believe him. If I can rig a strong enough spinner to get this kind of separation out of stuff I already have, well then buy me a new dress and call me Rube Goldberg, it'll be a good day.

If I go to my grave and never had the ability to make pea butter in my kitchen I think I will be fine with that. And BTW Rube Goldberg was a guy, Reuben Lucius Goldberg to be exact.

I know Rube Goldberg is a guy. I am glad you know his middle name. And if you don't want to centrifuge anything, that's fine. There are many other threads on this site, perhaps some that might engage your interest. In the future if I am being lighthearted perhaps I should use lots of emoticons so there's no confusion about tone.

[Dave the Cook]

As I have inquired earlier, are there particular models, sizes or types of centrifuges we should seek for food experiments? Also, I appreciated some of the warnings of things and types of machines to avoid. Like circulators bought surplus, you may never know where they have been, what prior chemicals they were used with or how well treated they were.

Here's what it says in Modernist Cuisine (p 2-284):

Not all available brands are listed; those given are the ones used in our research kitchen, arranged from least expensive to most expensive. In most cases there are other manufacturers who offer similar products, which may be as good or better.

Under "centrifuge," it says "Beckman-Coulter, Sorvall (now Thermo Scientific)" and lists a price range of $10,000 to $30,000. On the next page, under a list of "Handy Special-Purpose Tools," this remark is appended:

The prices listed here are typical for new equipment in 2010 . . . much of this equipment is available secondhand on eBay or from used scientific dealers at a substantial discount.

In the section titled "You Spin Me Right 'Round," (p 2-362) it goes into further detail:

Restaurant chefs would be well-served by units that are about the size of a washing machine and can process up to 3l/3 qt of food at a time, at rotational speeds up to about 30,000 rpm.

They also recommend a refrigerated model to counteract heat generated by air friction. There's also a page on centrifuge safety, and additional instructions for how to balance the load.

[technophile50]

The short answer is that higher g forces will separate smaller particles, and particles with less density difference from the liquid. Lower g's for longer times won't do the same thing. I've read that lime juice clarified at 48,000 g tastes much better than at 27,000 g, the threshold for clarification. Time will make a difference, but it's more important for very fine particles at high g's. Runs for separating out retrovirus particles may take hundreds of thousands of g's for 24 hours

The long answer is a bit more complicated, and if your not interested in the details, feel free to skip the following - I'm used to people's eyes glazing over when I start to ramble on about nerdy details of technology.

As particles get smaller, the variation in force with the variation in the number and velocity of water molecules hitting it becomes larger, because the total number of hits per unit time decreases. When the particles get small enough, the variation is large enough to cause Brownian motion. If you drop a large ball bearing, and a bb into a deep container of water, the bb will take a perceptibly longer time to reach the bottom. This is because the force of gravity pulling the objects through the water is proportional to their mass, which varies with the cube of their diameter; but the drag from moving through the water varies as their cross sectional area, which is proportional to the square of their diameter. So all other things being equal, a particle ten times smaller will have 1/1000 the mass but 1/100 the area, and fall - terminal velocity - 1/10 as fast(approximately, because all other things aren't exactly equal). The force fluctuations that cause Brownian motion will make the particles vary a little bit in speed; the smaller the particle, the larger the variation, and it will be unmeasurable on the ball bearing or bb. As the particle size approaches ~2 micron, the Brownian motion will approach the magnitude of the sinking motion at one g. For even smaller particles, or less dense particles, the effect of the Brownian motion will overcome gravity, keeping them in suspension as a colloid or emulsion. A surface layer of surfactant (soap) will keep fine particles from coalescing into larger particles that can sink (or float, in the case of low density particles like fat). Higher accelerations in a centrifuge will overcome the forces of Brownian motion for smaller particles, or particles with lower density differences from water. There's probably something in lime juice that's too small to scatter light and cause cloudiness, that won't separate out at 27,000 g's but will at 48,000 g, that alters the taste.

[dcarch]

As I remember, Brownian motion is also temperature related.

dcarch

[Paul Kierstead]

Thank you very much, Technophile. That was very interesting and informative. Hundreds of thousands of g's for 24 hours? That would be quite the machine; bearings, etc would all get seriously stressed. If you had one, you'd want to throw every cooking liquid you had in it to see what happened to each....

Edited February 24, 2011 by Paul Kierstead (log)

[JBailey]

My guess is that all the centrifuges capable of the higher rpm's are spinning in Tehran...

[rmillman]

I have used my centrifuge less since joing the agar clarification gang but in some instances such as in separations invovling solid, aqueous and oil phase, there is nothing like a quick spin in the fuge though I tend to spin slower and longer since it is an old machine and there is no telling how much abuse the rotor has dotten since it was an ebay purchase (I spin no more than at 50% of the rated limit for the rotor).

[ShaneH]

Has anyone used a centrifuge in the kitchen enough to recommend a particular type or capacity load or any such thing to go on? I am new to this forum and understand someone mentioned no "micros" and that it isn't necessary to have one the size of my washing machine. I've got my volumes on order and am itching to buy a centrifuge. If anyone has any retail ideas or brands I'd be open to hearing about them!

Thanks so much for your time! And for the record I've read the "cooking issues" link.

Have a great day and happy cooking,

Shane

[gfweb]

If you buy it on ebay make sure you get a look at the rotor and the things that hold the tubes or bottles. If all it has are ones for small tubes it won't be very useful for volumes of sauce etc.

If you plan on spinning big volumes you will also need a double pan balance to make sure they opposing tubes are of equal weight.

[ShaneH]

Thanks gfweb!

I found a Beckman J2-21 online, used but in "great condition"...I'm curious what you all think about the details I found:

Specifications: All instruments

Width 28 in. 710 mm

Depth 37 in. 950 mm

Height 50 in. 1270 mm

Weight 666 lbs. 300 kg

Max Speed 21,000 rpm

Max Volume 3 liters

Refrigerant R-502

Electrical Requirement 30 Amps, 220 Volts

Common Rotors:

JA 20 8 x 50 ml

JA 14 6 x 250 ml

JA 10 6 x 500 ml

JS 13.1 6 x 50 ml swinging

I know this is asking a lot but it seems to be a floor standing model, refrigerated, comes with a rotor (8 x 50ml)...would you all think that's overkill for home kitchen or if the price was right and it was a deal...would you get it?

[Jethro]

Mike,

I became interested in rigging a centrifuge when I read about Nathan Myrvold's pea butter. He centrifuged pureed peas into water, fibrous starchy solid and pea "butter". He used this lipid layer on crustini and said it was delicious. I believe him. If I can rig a strong enough spinner to get this kind of separation out of stuff I already have, well then buy me a new dress and call me Rube Goldberg, it'll be a good day.

Hello -

I have a centrifuge and just made pea butter for the first time the other day. I posted about it here: http://jetcitygastrophysics.com/2011/02/28/modernist-cuisine-at-home-pea-butter/

They use a 10000g centrifuge to make their pea butter. Mine is only 1520g, but I was able to get the same results, but it took over 3 times longer.

- Jethro

Edited February 28, 2011 by Jethro (log)

[runwestierun]

Thank you, Jethro. I figure my washing machine only pulls about 100 g's on a good day, so it looks like I am going to have to buck up and get a centrifuge. I read your blog post, thank you. I especially appreciate the advice about blendign the peas from a frozen state. I do have a Blendtec, so that's a good start.

[gfweb]

Thanks gfweb!

I found a Beckman J2-21 online, used but in "great condition"...I'm curious what you all think about the details I found:

Specifications: All instruments

Width 28 in. 710 mm

Depth 37 in. 950 mm

Height 50 in. 1270 mm

Weight 666 lbs. 300 kg

Max Speed 21,000 rpm

Max Volume 3 liters

Refrigerant R-502

Electrical Requirement 30 Amps, 220 Volts

Common Rotors:

JA 20 8 x 50 ml

JA 14 6 x 250 ml

JA 10 6 x 500 ml

JS 13.1 6 x 50 ml swinging

I know this is asking a lot but it seems to be a floor standing model, refrigerated, comes with a rotor (8 x 50ml)...would you all think that's overkill for home kitchen or if the price was right and it was a deal...would you get it?

300ml (in 50ml tubes) wouldn't be enough to make soup unless you served it in demitasse cups. It would make a practical volume of sauce.

What kind of volume will you be working with?

[Jethro]

Thank you, Jethro. I figure my washing machine only pulls about 100 g's on a good day, so it looks like I am going to have to buck up and get a centrifuge. I read your blog post, thank you. I especially appreciate the advice about blendign the peas from a frozen state. I do have a Blendtec, so that's a good start.

You can find decent ones for relatively cheap. I found mine for $500 at a local used lab equipment warehouse. Dave Arnold of Cooking Issues got his from eBay. Just keep your eyes peeled!

[runwestierun]

Thank you, Jethro. I figure my washing machine only pulls about 100 g's on a good day, so it looks like I am going to have to buck up and get a centrifuge. I read your blog post, thank you. I especially appreciate the advice about blendign the peas from a frozen state. I do have a Blendtec, so that's a good start.

You can find decent ones for relatively cheap. I found mine for $500 at a local used lab equipment warehouse. Dave Arnold of Cooking Issues got his from eBay. Just keep your eyes peeled!

Do you think I am overly cautious being afraid of a used centrifuge? I just think of the stuff we put in them--carcinogens (so many different benzene derivatives), smelly things (beta mercaptoethanol ), so many things with radioactive tracers. Maybe if I could find a used one with a good provenance. Nice clean centrifuge just driven by an old lady on Sundays making pea butter.

[Chris Hennes]

A lot of these centrifuges don't come with the buckets/tubes at all, so the parts that touch your food are going to be purchased separately anyway. I don't know how difficult it is to remove that sort of substance from the containers you do purchase, though.

[gfweb]

I worry about this top

Thank you, Jethro. I figure my washing machine only pulls about 100 g's on a good day, so it looks like I am going to have to buck up and get a centrifuge. I read your blog post, thank you. I especially appreciate the advice about blendign the peas from a frozen state. I do have a Blendtec, so that's a good start.

You can find decent ones for relatively cheap. I found mine for $500 at a local used lab equipment warehouse. Dave Arnold of Cooking Issues got his from eBay. Just keep your eyes peeled!

Do you think I am overly cautious being afraid of a used centrifuge? I just think of the stuff we put in them--carcinogens (so many different benzene derivatives), smelly things (beta mercaptoethanol ), so many things with radioactive tracers. Maybe if I could find a used one with a good provenance. Nice clean centrifuge just driven by an old lady on Sundays making pea butter.

Id worry about this too. But I'd use new tubes. With caps or Saran wrap and sleep easy.

Sent from my Droid using Tapatalk

[Jethro]

My centrifuge was clean inside, and with a wipe down with a bleach soaked rag and soaking the buckets in the same, it's been fine. Your food will most likely be in test tubes, plastic containers you've bought (like me) or heat sealed bags (like Cooking Issues), so contamination will be highly unlikely.

There are several makes of the centrifuge I have - a Beckman TJ-6 - on eBay right now. But if possible go for something more powerful like a Jouan C412 which does 4000g's. Could have done the peas in 3 1/2 hours with that one.

Cooking Issue's excellent post on different centrifuges is here: http://www.cookingissues.com/2009/07/21/oh-lord-wont-you-buy-me-a-new-centrifuge/

My post on my centrifuge is here: http://jetcitygastrophysics.com/2010/12/13/you-spin-me-right-round-enter-the-centrifuge/

Happy hunting!

[ShaneH]

I'm excited I just went and looked at a centrifuge, Sorvall RC-2B and bought it. It seems adequate for my own needs, comes with a couple rotors which would support upto 1.5 liters, certainly not a crazy amount...but then again it's just me tinkering. It gets delivered next week...now if only the books would get here next week!

[dcarch]

With Lab centrifuges, I would assume the materials used cannot not be contaminated by normal chemicals or biological agents.

However, if they had been used for radioactive material, that can be very different. I don't think there is an easy way to clean radioactive contamination.

dcarch