Gelatin filtration experiment

[isomer]

This weekend my kitchen project was a gelatin clarification....with photos!

My ultimate intention is to make a clear bloody mary mix at the end of the summer with the tomato juice from all the fresh tomatoes I'm going to roast and freeze. In the meantime, I tried it with canned tomato juice.

The first thing I did was pour the juice through a fine-mesh strainer to remove as much pulp as I could:

The resulting juice tastes basically the same, but with less mouth feel than the original canned juice.

After that I strained again through a coffee filter:

Remember to wet the paper filters with water before pouring in the juice. This expands the fibers in the filter to the correct size (see? two years in an organic chem lab did pay off!) I was pretty surprised at how much pulp was left after the initial straining. As you can see, it's quite a lot:

There's very little taste difference between the filtered juice and the initial strained juice, but it does have noticeably less mouthfeel.

The next step is to weigh out 0.5% gelatin w/w. To make things simple, I weighed out 500g of juice, which is half a litre, and 500g x 0.5% = 2.5g of gelatin powder:

I warmed about half a cup of the liquid, and mixed in the gelatin powder. After it was incorporated, I stirred the half cup into the remaining juice. From there, it went into the freezer overnight. The next morning, I took the frozen block and set it over a cheesecloth

lined strainer in the fridge:

It took about 2 days for all the liquid to melt out, and leave just a pile of sludge. I kept pouring off the liquid every 12 hours so that I would know when it was done. Here is the sludge at the end:

And here, in the two small jars on the right, is the clarified juice:

I've put it next to the juice that's been through the coffee filter so you can see the difference in colour. Those little mason jars are 250ml each, and you can see I got about 340ml of product, which is a yield of 340ml / 500ml = 68%.

Amazingly, the clear juice tastes virtually identical to the filtered juice! In a blind test, I don't know that I could tell the difference, except for the slight grittiness of the filtered juice compared to the clarified one. The bloody mary came out really well, too!

[Tri2Cook]

Cool. I did something similar for a party not too long ago. I made my own clamato with clam juice, tomato water and a few other ingredients, clarified it and added vodka. I called it Caesars Ghost.

[TheSwede]

It is very hard to judge the color of the end product in those jars.

Was it totally water clear?

[edsel]

Making bloody Marys from tomato water is fun. Especially if you can make it absolutely clear (like water).

Shola has a fun post about this on his blog.

I present you the absolutely clear "Bloody Mary".

Clearly it isnt a bloody mary but it tastes exactly like one.

What fun !

[isomer]

It is very hard to judge the color of the end product in those jars.

Was it totally water clear?

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It's not totally clear - it's more like the colour of pale apple juice. I'm pretty sure, though, that if you start with tomato water it will come out totally clear.

[FastTalkingHighTrousers]

It is very hard to judge the color of the end product in those jars.

Was it totally water clear?

←

It's not totally clear - it's more like the colour of pale apple juice. I'm pretty sure, though, that if you start with tomato water it will come out totally clear.

←

That's true! I've done it in the past with the water from different colored heirloom tomatoes, .15% agar and a superbag.

The resulting liquid is "water clear" and is bursting with heirloom tomato deliciousness.

[gfweb]

http://www.typepad.com/t/trackback/2317252/31149810 has Shola's method for a clear bloody mary and some fabulous pix too.

[Ndy]

This guy used some kind of micron filter paper to create completely clear bloody mary. Impressive.

http://studiokitchen.typepad.com/studiokit...mary-quite.html