I want to play with Adria's faux caviars

[cdh]

Having read about the El Bulli faux caviar technique here a number of times, the urge to play with the technique has come over me. I've been googling up a storm and have had no luck finding a source of the sodium alginate.

I've tried health food stores and constantly get a funny look from the counterfolk there, though there are google indications that somebody or other used to make a pure sodium alginate dietary supplement at some point in time...

I'm wary about going to chemical supply houses because who knows whether the impurities that won't affect lab reactions will affect taste...

I'd rather not order from Texturas El Bulli because I don't read enough spanish to figure out what's what, or where on that website to place an order.

I've found a kids' science website that sells a kit for making "worms" that appears to use the alginate CaCl reaction, but their stuff appears to be pre-colored.

So, anybody found a source?

Anybody played with the technique with fun results? So many possibilities.

[rxrfrx]

{see next comment}

Edited January 14, 2006 by rxrfrx (log)

[rxrfrx]

Here's a couple:

4 ounces for $4, but it's not being sold as a food product

1 ounce for $4.44, sold as a food ingredient

1 pound for $16.79, sold as dietary supplement

[Thesorus]

eventually, ordering chemicals to do Adria's recipe will alert the homeland security, and you will have the CIA (well, not the cullinary one ) come to your house wondering if you're not building a bacteriological bomb !!! :-)

[cdh]

Thanks for the links.

Edited January 14, 2006 by cdh (log)

[wattacetti]

I'm wary about going to chemical supply houses because who knows whether the impurities that won't affect lab reactions will affect taste...

←

Um, in general, the stuff from chemical supply houses is usually purer than the stuff one would find in health food stores (or elsewhere) as those impurities generally tend to screw up experiments. The impurities may impart other tastes into the final product.

It was interesting cooking with molecular biology-grade NaCl (really salty…).

[cdh]

Interesting. A friend who had had the insane idea of going back to college to take organic chemistry told me that the formulators of lab grade stuff pay no attention to the effects of consumption, based in the idea that nobody in a lab is going to consume the results of anything done there.

Consequently, I'm more interested in getting stuff made with the idea that it will be consumed rather than made with the assumption that nobody will be so dumb as to consume it.

[MGLloyd]

Speaking as a former analytical chemist, there are different grades of purity among chemicals intended for lab use. Some of the common grades include 'industrial', 'solvent' and 'reagent' grade. If you are ordering something 'reagent' grade, it will be the most pure product manufactured. If the underlying chemical is consumable, a reagent grade of that chemical certainly will be. If you are buying lesser grades of a consumable chemical, you will want to look at the description to insure that it does not contain any additives that are harmful to health. But I would generally feel pretty darn comfortable consuming any edible chemical that was 'solvent' or 'reagent' grade. An exception would be ethyl alcohol, which if it is not 'reagent' grade, is generally adulterated with a chemical so that it cannot be consumed.

[Shalmanese]

It was interesting cooking with molecular biology-grade NaCl (really salty…).

←

Huh? Commercial salt is 99.9% NaCl. I doubt the 0.1% extra would make a perceptible difference.

[wattacetti]

Huh? Commercial salt is 99.9% NaCl. I doubt the 0.1% extra would make a perceptible difference.

←

The perception is saltier; I'd equate it to the difference one would have by comparing Sifto to say sel de guérande.

[rxrfrx]

Speaking as a former analytical chemist, there are different grades of purity among chemicals intended for lab use.  Some of the common grades include 'industrial', 'solvent' and 'reagent' grade.

I was gonna suggest he could buy some ultrapure stuff from Sigma... but I figured nobody's interested in making fake caviar that costs 10X more than the real stuff...

[jsolomon]

As an analytical chemist/microbiologist working in Food/Pharmaceuticals, my suggestion is to ask for "USP" or "Molecular Biology" grade reagents.

[Jim D]

Having read about the El Bulli faux caviar technique here a number of times, the urge to play with the technique has come over me.  I've been googling up a storm and have had no luck finding a source of the sodium alginate. 

I've tried health food stores and constantly get a funny look from the counterfolk there, though there are google indications that somebody or other used to make a pure sodium alginate dietary supplement at some point in time...

I'm wary about going to chemical supply houses because who knows whether the impurities that won't affect lab reactions will affect taste...

I'd rather not order from Texturas El Bulli because I don't read enough spanish to figure out what's what, or where on that website to place an order.

I've found a kids' science website that sells a kit for making "worms" that appears to use the alginate CaCl reaction, but their stuff appears to be pre-colored.

So, anybody found a source?

Anybody played with the technique with fun results? So many possibilities.

←

I would go to a reputable chemical supply house like:

http://www.sigmaaldrich.com/Local/SA_Splash.html

They often have different "grades" from "utility" grade all the way up to "USP" which are use for pharmaceutical manufacture.

[scott123]

4 ounces for $4, but it's not being sold as a food product

←

Chris, I'd give these guys a call. Dharma trading are pretty crunchy folks. I'd be really surprised if the alginate wasn't food grade.

You could also contact an alginate manufacturer and see if you can get a sample. I've done that with a few retail scarce ingredients. It helps if you give them the impression that you're considering their ingredient for a commercial application.

This stuff is definitely on my shopping list. Sounds like fun. I found carageenan (irish moss) at a local brewery supplier and look forward to experimenting with that as well. I'm guessing that since they're both seaweed extracts, they must be similar.

Edited January 16, 2006 by scott123 (log)

[cdh]

Sigma's website offers a bunch of varities of "alginic acid, sodium salt", which sounds to be what sodium alginate is... but none of them mention any of the grades you all have mentioned here... just what appear to be different manufacturers. The US Pharmacopea must not extend into seaweed extracts.

Thinking about all this purity stuff, sodium alginate is derived from kelp. Kelp is available in any Japanese market in the dashi making supplies section. Is there a way to process kombu into a useful source of sodium alginate for these sorts of experiments? I'd imagine it would need to be soaked for a long time to remove sea salt and other minerals it might have absorbed... How much of the flavor can one wash away and still maintain the gelling properties?

And would dropping dashi into a CaCl2 solution result in pearls??

[rxrfrx]

And would dropping dashi into a  CaCl2 solution result in pearls??

There would be too much non-alginate material in any crude kelp extract.

However, it doesn't sound too hard to extract it yourself (though I don't know why you'd want to... the stuff is only $16/lb).

A rather complete review of alginate purification methods can be found here (NB you must turn off javascript before clicking the link, or you'll get redirected away).

From the linked article:

To extract the alginate, the seaweed is broken into pieces and stirred with a hot solution of an alkali, usually sodium carbonate. Over a period of about two hours, the alginate dissolves as sodium alginate to give a very thick slurry. This slurry also contains the part of the seaweed that does not dissolve, mainly cellulose. This insoluble residue must be removed from the solution. The solution is too thick (viscous) to be filtered and must be diluted with a very large quantity of water. After dilution, the solution is forced through a filter cloth in a filter press. However, the pieces of undissolved residue are very fine and can quickly clog the filter cloth. Therefore, before filtration is started, a filter aid, such as diatomaceous earth, must be added; this holds most of the fine particles away from the surface of the filter cloth and facilitates filtration. However, filter aid is expensive and can make a significant contribution to costs. To reduce the quantity of filter aid needed, some processors force air into the extract as it is being diluted with water (the extract and diluting water are mixed in an in-line mixer into which air is forced). Fine air bubbles attach themselves to the particles of residue. The diluted extract is left standing for several hours while the air rises to the top, taking the residue particles with it. This frothy mix of air and residue is removed from the top and the solution is withdrawn from the bottom and pumped to the filter.

The next step is precipitation of the alginate from the filtered solution, either as alginic acid or calcium alginate.

[chardan]

Check Amazon.com. Turned up some promising results for me. -J.

[jsolomon]

The US Pharmacopea must not extend into seaweed extracts.

←

It does, but molecular biology grade from Sigma will be equivalent.

[pounce]

I'm not sure if this is posted somewhere else, but I found a link to the recipe and process for Chef Ferrán Adriá's Apple Caviar

It includes video of the process...COOL!!

Edited January 16, 2006 by pounce (log)