Comments on: Simple Agar Clarification vs Gelatin Clarification: Another Difference The International Culinary Center's Tech 'N Stuff Blog Thu, 09 Jan 2014 18:17:16 +0000 hourly 1 By: Dave A Fri, 31 Jul 2009 20:16:55 +0000 I used to do lime juice rotovapping all the time. I guess there is no way to measure how much flavor I lost. I used to throw away the stuff in the distillation flask and mix the volatiles with a 2:1:0.1 Citric,Malic,and Succinic acid mix. We blind tasted against lime juice and used to win! I did use twice as much volatiles. So to make 500 ml of clear rotovapped lime I would use 1000 ml of fresh lime.

By: schinderhannes Fri, 31 Jul 2009 14:44:36 +0000 Rotavapping won´t due it, too delicate, when you ned to cath volaites and residue and cut out water in the middle, I bet you will be loosing plenty of taste on both ends, plus you need to heat.

Also why force freeze and force thaw?
Semi freeze slowly to generate large crystals of water in the freezing, drain juce of them crystals (of nearly pure water), done!

By: Dave A Fri, 31 Jul 2009 14:30:18 +0000 It would be possible to do a fast freeze (LN) of the agar block and then a force-thaw at 30C. That should concentrate it. Another option would be to do simple agar plus rotovapping. Save volatiles, throw away water, add back volatiles. One problem I see is that part of lime juice’s instability is due to concentration. It has been years since I read the papers, but I think lime juice isn’t protected by normal freezing or by vacuum packaging. I know from experience that the acid residue in the distillation flask doesn’t taste good. I always attributed that to just being warm (40C), but perhaps it was being degraded due to concentration? I dunno. What’s also intersting is that lime volatiles degrade when left by themselves but are more stable in a mixed drink. I guess I need to do more research.

By: schinderhannes Fri, 31 Jul 2009 14:16:16 +0000 Another idea for some lab equipment that might be useful in the kitchen:
If you take a cross flow ultra filtration membrane and pump some clarified stock over it, you will be able to do two things with this rig:
as ultra filtration membranes allow small molecules namely water, but also e.g. alcohol and simple ions (Na+ Cl-) to pass thru, whilst retainig proteins (the taste of you broth), you can desalt and concentrate a stock by dong so. (Extremly mild process, used for peptidic drugs).

Might be fun to produce the mother of all consommes this way!
Later on you can salt it with any freaking salt you want, to the precize perfed taste.

good luck…

By: schinderhannes Fri, 31 Jul 2009 14:08:49 +0000 Curiosity…

I sort of fell in love with your website, and all the ideas it ventilates.
Unfortunately I am currently unable to do kitchen chemistry, simply too busy doin the conventional stuff.
Do you think you will find time to try the semi freezing / concentrating up (either pre or post Agar clarification) of some juice or stock.
I strongly feel this must be the way to the most concentrated clarified lime juice ever!

By: Jeremiah Blatz Tue, 28 Jul 2009 03:58:33 +0000 Dave,

Thank you very much for:
1) You lucid answer
2) Entertaining my n00b questions
3) Your fantastic blog

Agar and a scale going on the shopping list…

By: Dave A Mon, 27 Jul 2009 18:28:17 +0000 Hi Jeremiah,
Well, clarified stuff does look fantastic, and sometimes that is reason enough –fruit soups, etc–; but there are other reasons. Clarified products tend to have a different mouthfeel from unclarified products (cause the stuff in them that made them cloudy has been removed). Usually, the mouthfeel is lighter, smoother. Also, the clarified products usually taste “cleaner.” For instance, clarified grapefruit juice tastes clean and bright, and has lost some of the bitter components of the juice without losing characteristic grapefruit flavor. One last point: carbonation works much better on clarified products (we cabonate a lot). Unclarified products tend to foam a lot because all the turbid stuff provides nucleation sites for bubbles.

By: Jeremiah Blatz Sun, 26 Jul 2009 03:58:25 +0000 Dave,

I apologize in advance if my question seems stupid or philistine, but why (other than “it looks cool” would you want to clarify a liquid?

I can think of a few, perhaps you don’t want any gelatin in your stock, or maybe for some reason you don’t want any oil (e.g. hot peppers). Does it have other effects, and are they readily predictable?

By: alexgz Thu, 23 Jul 2009 23:45:12 +0000 Following your post of the nut puree centrifuge experiment… one proposed explanation of why adding simple syrup to a nut puree pre-centrifuge would be that sugar has a tendency to bind to things really well and as sugar is heavier than oil (per same level of volume) than it only makes sense that the oil would be clearer because of the fine particulate removal still floating around being bound up and pulled down by the sugar, just a thought, hope it helps.

By: Joe L Tue, 21 Jul 2009 07:26:52 +0000 I love the the things you do, but with all of these techniques, I challenge you to do something so savvy which makes dining more accessible to those who cant afford $300 a couple for a dinner.

These techniques if mass produced should be a gateway for elegant cuisine for the masses.