9 replies to this topic

[gfweb]

I've looked on the wiki and in multiple posts but can't find any real instructions as to how to use it.

[mkayahara]

It's pretty straightforward to use as a thickener: you add it in very, very small amounts until you reach the thickness you want! Are you trying to use it for a different application?

Edit: Take a look at Dave Arnold's Hydrocolloids Primer and the Khymos recipe collection as well.

Edited by mkayahara, 16 July 2012 - 10:24 AM.

[gfweb]

I'm thinking mainly as a thickener. My questions are...

Must you heat it to get a gel? How hot?

Can the thickened sauce be reheated?

How long is a xanthan sauce stable? For example, could I thicken a BBQ sauce with it and just keep it in a squeeze bottle for weeks?

Will it thicken any aqueous liquid? How much fat can there be in the liquid.

I'll probably think of more questions.

Thanks!

[Mjx]

I'm thinking mainly as a thickener. My questions are...

Must you heat it to get a gel? How hot?

Can the thickened sauce be reheated?

How long is a xanthan sauce stable? For example, could I thicken a BBQ sauce with it and just keep it in a squeeze bottle for weeks?

Will it thicken any aqueous liquid? How much fat can there be in the liquid.

I'll probably think of more questions.

Thanks!

Check out the primer mkayahara linked to; I just took a quick look at it, and realized this was a must-save.

[mkayahara]

All your questions - and more! - should be answered in the docs I linked to, but for posterity's sake...

I'm thinking mainly as a thickener. My questions are...

Must you heat it to get a gel? How hot?

Xanthan gum doesn't gel on its own; you need to use it in combination with other hydrocolloids to make a gel. It will thicken both hot and cold liquids.

Can the thickened sauce be reheated?

Yes.

How long is a xanthan sauce stable? For example, could I thicken a BBQ sauce with it and just keep it in a squeeze bottle for weeks?

From a thickening standpoint, yes. The xanthan gum shouldn't affect it from a microbial standpoint, so if you're comfortable using BBQ sauce that's been sitting around for weeks, then the xanthan gum shouldn't change that.

Will it thicken any aqueous liquid? How much fat can there be in the liquid.

It will thicken any aqueous liquid as well as alcohol up to 50% or 60%. I'm pretty sure you couldn't included enough fat to be a problem; if you're working with an emulsion, xanthan will even help stabilize it. Xanthan gum is a popular ingredient in many bottled salad dressings, for instance.

[gfweb]

Thanks. Those links are great, as is your answer.

A lot of those recipes in Khymos seem only use xanthan gum without another hydrocolloid...or is there enough hydrocolloid in the food to be the second one required for gelling?

[KennethT]

As far as I was aware, Xanthan isn't a thickener, technically speaking, it's a stabilizer. So, it's really meant to keep particles (like spices, etc.) in suspension so they won't settle out. That's why it's commonly used is bottled dressings and sauces so from the time of filling to the store shelf it shouldn't separate. Xanthan creates sauces that are thixotropic - meaning that the fluid at rest tends to stay at rest, but will move easily under shear. Like ketchup - you can mound it and it stays put, but it spreads easily with a spatula. While it's doing that job, it will thicken as well, but if you use too much it gets a bit of a mucous-y texture. It also works synergistically with other hydrocolloids like LBG and will help it do its job and using less of it. For true thickening, I'd consider an ultra-tex or ultra-sperse starch based thickener by National Starch. If thickening cold liquids, the Ultra-tex line works great... it tends to clump in hot liquids, but for cold liquids, you just whisk it in a little at a time and it thickens, with no heating required. It's flavorless and has a nice creamy mouthfeel. Ultra-sperse is better for thickening hot liquids. They're both heat and reheat stable, freeze stable, etc.

Edited by KennethT, 16 July 2012 - 12:25 PM.

[mkayahara]

A lot of those recipes in Khymos seem only use xanthan gum without another hydrocolloid...or is there enough hydrocolloid in the food to be the second one required for gelling?

I would assume that they're just using it as a thickener, not a gelling agent. Can you point to an example where it calls for only xanthan but is intended to gel?

As far as I was aware, Xanthan isn't a thickener, technically speaking, it's a stabilizer.

I don't think this is correct: xanthan is both a thickener and a stabilizer. What it doesn't do on its own is gel. That is to say, no matter how much xanthan you add, you won't turn the liquid into a solid (even a wobbly solid like Jell-O), you'll just get a thicker and thicker (and eventually mucous-y) liquid. My understanding is that xanthan can form gels when combined with locust bean gum or konjac gum, but I've never actually tried it out for myself.

[KennethT]

Right - it works synergistically with gelling agents such as LBG so you can get much better results while using less.

[ChrisZ]

Here are my own personal notes on xanthan gum, compiled from khymos, MC, wikipedia and others:


Xanthan gum is a thickening / emulsifying agent produced by the fermentation of carefully grown bacteria.
Xanthan gum is especially valued because only very small amounts are needed to thicken a liquid, but the viscosity decreases if the solution is mixed / stirred or chewed. From a practical point of view this means a sauce can appear thick on the plate but will not feel thick or gummy in the mouth, or a smoothie can have particles suspended in it (eg fruit, spices, muesli) that won’t fall to the bottom but can still be easily drunk though a straw.
Xanthan gum does not change the colour or taste of food.
Xanthan gum is used to stabilise sauces or dressings that contain small particles (eg herbs, spice powders), and can help prevent dairy sauces from curdling without dulling the flavour in the way that starches can.
It is also commonly used in ice-creams, as it prevents ice crystals forming when ice cream is melted and re-frozen.
Usage guide: .2% to .5% by weight, very rarely more than 1%. Too much will produce an unpleasant slimy texture.