# gelatin/agar clarification



## spoiledbroth (Nov 20, 2015)

Hmm,

I had sort of been aware of this technique by name but never exactly read how to do it. I stumbled upon this thread at egullet.org yesterday and it seems pretty simple (you should read through the thread if you're interested)... more or less you can easily clarify vegetable stocks or juices or other weird ingredients (meat stocks not great because they'll form a pretty good gel in the first place and the more gelatin in the stock the lower the yield) by dispersing 0.5% (by weight of stock) gelatin into the warm stock, freezing completely and then allowing to thaw in the refridgerator over a strainer or whatever you fancy. 

There are some pretty neat suggestions like peanut butter consomme (no surprise if you're familiar with Ideas in Food, which they reference heavily in the thread)... I think in theory if you made a really "weak tea" stock (ie, skimp on bones, use instead a little meat or off cut or offal to keep overall gelatin low) you could probably freeze and filter it to get a decent result. 

I had also seen the precipitation method on chefsteps but that looks pretty gnarly to me, I also heard the chemical they used is (prohibitively) expensive. 

I thought I'd put this here because I did a good search and only found one mention of someone wanting to try something like this method with some SV bag juice (mmm bag juice :spin chair... Could be fun!

Here's McGee on the subject.

Anybody tried this or have any thoughts on the subject? FWIW before you dump on peanut butter consomme make yourself some "west african peanut soup"


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## buttermilk (Nov 20, 2015)

I've used both of these methods as well as vacuum clarification and centrifugal separation. For casual and small quantity usage, agar is great. It's clean tasting (in this use), highly clarifying, and very easy. The significant downfall of it is an extremely low yield despite large starting volumes. It also at least 24 hours. 

There are other methods that I'm happy to go into if you want, but I'd suggest starting with agar. What was the chem that Chef Steps referred to? Pectinex of one kind or another?


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## DamageInc (Nov 20, 2015)

At timecode 13:00, Heston makes a boosted stock which he then turns into a consomme. It seems that he just freezes the stock and lets it melt over the cloth. Looks like the natural gelatin from the wings keeps the gunk too thick for the cloth and only clear liquid runs through.

[video=youtube;XAZGQql9Dh4]https://www.youtube.com/watch?v=XAZGQql9Dh4[/video]


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## spoiledbroth (Nov 20, 2015)

^ wow great video. I like Heston alot, and I had not considered how the temperature at which you strain might affect yield. I am not very well versed in gelification, having only made preserves a handful of times. 



buttermilk said:


> I've used both of these methods as well as vacuum clarification and centrifugal separation. For casual and small quantity usage, agar is great. It's clean tasting (in this use), highly clarifying, and very easy. The significant downfall of it is an extremely low yield despite large starting volumes. It also at least 24 hours.
> 
> There are other methods that I'm happy to go into if you want, but I'd suggest starting with agar. What was the chem that Chef Steps referred to? Pectinex of one kind or another?


I would be very interested to hear what you have to say about anything. It sounds like you either have great access to resources or (better in my opinion because I work in the industry) have worked in some truly wonderful kitchens. 

The chefsteps thing I referenced is here (sorry about the facebook link) - methylcellulose f50. Not sure if thats the same as Pectinex. This is all pretty new to me.

I'm curious how low the yield is, 50%?


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## buttermilk (Nov 24, 2015)

spoiledbroth said:


> ^ wow great video. I like Heston alot, and I had not considered how the temperature at which you strain might affect yield. I am not very well versed in gelification, having only made preserves a handful of times.
> 
> 
> I would be very interested to hear what you have to say about anything. It sounds like you either have great access to resources or (better in my opinion because I work in the industry) have worked in some truly wonderful kitchens.
> ...



I have been able to work in some great kitchens, but I had a refrigerated centrifuge before I got to any of them. Part luck, part resourcefulness. A refrigerated centrifuge is ideal for clarification in all ways besides speed. You can spin a batch for an hour without any of the quality degradation that happens necessarily as a result of heat (a combination of friction within the chamber and extremely large gravitational pressures applied to your samples). It has the added benefit of density seperation. i.e. buzz a bunch of spring peas to a fine paste, spin them for an hour, and you'll have defined layers of pea water (I know), fat, starch, and fiber.

Vacuum filtration is very effective but slow and a pain in the ass. The most accessible setup for this utilizes a Buchner funnel and flask tied into a source of vacuum such as a venturi tube and a sink or a vacuum pump specifically able to withstand moisture. The filters are extremely fine and, depending on your product, can be filled after producing as little as 100ml. When a paper filter is full, you have to reset and re-establish your seals to keep a vacuum. Cheap to set up and useful for smaller quantities.

Methocel F50 is a great solution for liquids that will be boiled as part of the process. The methylcellulose binds proteins (which is why it's most commonly used for foams or for stablization) but the agitation of boiling deliberately breaks the structure preventing your product from just turning into a solid block. Methocel hydrates cold and typically over the course of a few hours, so this kind of heat works against everything the methocel is trying to do. If you're going to do this, make sure you're using F50. There are a million methocels and, though it's likely others would work, I have no idea which would or wouldn't.

Pectinex is an entirely different product that works enzymatically. It had historically been difficult to obtain, but it seems you can get Ultra SP-L pretty easily these days. Pectinex would really only be effective against raw vegetables, fruits, and their juices. The enzyme attacks and ruptures the pectin structures allowing it to fall out of solution. Useful for effecting color, clarity, mouthfeel of raw juices and for enzymatically "peeling" raw fruits.

Gelatin clarification is effective but, similarly to agar, produces low yields (far less than 50%) but requires significant freezer and fridge space. If you're working with a stock made from bones, you will have already incorporated plenty of gelatin to use this method. If you're working with anything else, weight your total liquid and add 1% (by weight) of gelatin sheets. Powder would work but you'll have to figure out the conversion (they're not directly interchangeable) and hope that the powder is around 160 bloom. Freeze your gelatinized liquid then rest it in a cheesecloth (or finer) lined strained in your fridge for one or two days.

Agar is low-yielding (25% or less?) and slow (1-2 days). However, it's cheap, easy, and able to hydrate in most liquids (including acids). Always add agar to a cold liquid and disperse the hell out of it with a blender, etc. Agar hydrates at, I think, 208*F but just assume boiling. Constantly scrape the bottom of your pan because agar settles, and burns, quickly. So, it's not a great solution for liquids that need to taste fresh unless you have a plan to rectify that afterwards. Use between .2% and .5% agar by weight of your liquid. It will depend on your liquid and your agar. If possible, always use Telephone brand. Telephone agar is consistent is far less likely to taste like death than even "designer" agars. After your agar block is fully cool and set, break up the block and place in a cheesecloth-lined strainer to drip at room temp for a day or two. 

There's also bentonite clay which has it's uses but is also particular, and the Buon Vino filter which is a few hundred dollars. I'm happy to answer questions if you have them.


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## DDPslice (Nov 24, 2015)

Omg peanut consume sounds so good I want to eat so much I dump peanut consumme. 

Now I'm going to step into an area I have absolutely no idea about and I will come back to, after I read all the links, but for now. Do you want the gelatinous mixture solid at room temp or are you serving it cold? Because I just made a pig's feet broth and yes the gelatin was VERY low yielding but non the less being able to absorb lots of flavo(rs)noids I used it as my fat in my latest omelet so that makes me think. Why can you just make a heavily reduced broth (1/8 to 1/12) and then add strait gelatin or arrowroot and make some brothy jello?


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## cheflivengood (Nov 25, 2015)

Let's start with your goal. Why or what do you want to use this technique for?


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## DDPslice (Nov 25, 2015)

oh whoops i went the other way, scratch that, maybe you can just get micron filters in succession to about 10 microns or so.

http://www.amazon.com/dp/B006C6NY3Q/?tag=skimlinks_replacement-20


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## JLaz (Dec 2, 2015)

In my experience, gelatin clarification works well but you have to be cautious of your gelatin concentrations. Too much gelatin and your yield becomes too tiny. Not enough gelatin can cause the stock to not gel. If making consomme though, the traditional pleasant mouth-feel of gelatin is lost through gelatin clarification. Gelatin is useful for clarifying high volume at low cost assuming there is no time constraint.

Agar clarification has a lot of benefits such as high acidic applications. Agar also sets faster than gelatin and the extraction process is also a lot faster. However, a lot of practice is needed to extract just the right amount of yield to prevent extracting cloudy liquid from the agar mass. Interestingly also, the first liquid to be extracted also has a more concentrated flavor.


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