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Hervé This discovered that one can make chocolate mousse with chocolate and water only.

This recipe is shown in this MasterChef video, and also detailed here.

Essentially, one melts chocolate with water, then whisks it over an ice bath to incorporate air bubbles, and after a while the mousse is formed.

Is this property unique to chocolate? Would this be possible, with, say, a strawberry purée?

rumtscho
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user256872
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    This outcome of this technique is called a 'Water Ganache'. When I helped run a small chocolate company this was how we made our vegan/dairy-free truffles. – Mehmet Apr 20 '21 at 07:00
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    Probably depends on how patient the moose is – Todd Wilcox Apr 21 '21 at 15:00
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    Well, I'm pretty sure any moose can be beaten into liquid food, if that helps. – Jason C Apr 21 '21 at 20:12
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    @ToddWilcox when the lawmakers forbade foie gras because it is too cruel to beat food into geese, I don't think they intended you to switch to beating food into meese! – rumtscho Apr 21 '21 at 21:22

2 Answers2

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Chocolate is a solid at room temperature, strawberry puree is not, so I strongly doubt that the strawberry would result in a foam.

The reason chocolate would form a solid foam is that it is largely composed of a two substances - sugar and fat. Together with the air these can form a solid of fats (similar to whipped cream) with microscopic sugar crystals helping keep it in place.

The only thing a strawberry puree would have that might reach similar consistency is the sugars. If you were to heat to a high enough heat that the sugars polymerize crystallise (like in candy), and whisk, you might get a structure like a mousse, but it would be crunchy.

bob1
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    And I'd wager you loose a lot of the strawberry flavor before the sugar becomes fixed – Hobbamok Apr 20 '21 at 09:53
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    Sugars do not polymerize during candy making - they crystallize, or otherwise solidify in an amorphous or glassy phase. The consistency is dictated by the fraction of water remaining - the heat is used to adjust the quantity of residual water in the mix, as indicated by its boiling point which increases as the water fraction goes down. – J... Apr 20 '21 at 11:49
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    Bonus: to achieve a crunchy foam candy, you mix in baking soda. That's the only method I know anyway. – kitukwfyer Apr 20 '21 at 18:44
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    @J... good point, I couldn't think of the term at the time. I'll edit that in. – bob1 Apr 20 '21 at 20:23
  • I think that you could beat strawberry puree in a mousse using the technique for Italian meringue. You beat the (filtered) puree with a whisk, and then slowly pour hot sugar in the mix, while beating. You might need gelatin to stabilize the compound. – Vladimir Cravero Apr 21 '21 at 07:02
  • @VladimirCravero possibly, but the OP question was more about being able to make a foam from things other than chocolate in a chocolate/water mix. My point was that you couldn't, not without adding extra things. – bob1 Apr 21 '21 at 08:24
  • Fair enough. I interpreted OP question more like "what ways are there to make everything into a foam" rather than "can I make this into a foam without adding anything", hence my comment. – Vladimir Cravero Apr 21 '21 at 08:55
  • @VladimirCravero, you got me thinking. I am sure someone has tried it but it might be possible with a high pectin fruit, like making a setting jam into a foam. The only problem might be that the foaming process destroys the pectin protein somehow. – bob1 Apr 21 '21 at 21:54
  • When I made the comment, I just saw this video: https://youtu.be/tfn-LC254Hk?t=264 I just checked back and I was remembering wrong, you also need egg, fruit+sugar is not quite enough at least for raspberry puree. – Vladimir Cravero Apr 22 '21 at 10:32
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The beating of a liquid to a foam is not unique to a chocolate-and-water mixture. Neither is it something that works with any random liquid. What you need is an emulsion or a colloid which contains something that can hold the bubbles of the foam, and

  • has the right proportion of that "something" to the liquid part
  • has the right particle/droplet size
  • is being processed at the right temperature (or change of temperatures, for example a sponge cake is a foam that has to start at room temperature and then get heated to first expand and then set into a stabilized state).

Ferran Adria has created this very simplified diagram:

diagram

Translated from the "base" column, the diagram states that you need the proper amount of gelatin, fat, egg white or starch for a foam. The not-so simple version is that

  • binders other than gelatin will also work
  • protein suspensions other than egg whites will work (e.g. the notorious aquafaba)
  • when you have a liquid which has more than one of these, all bets are off. It might be helpful for making the foam (e.g. in chocolate, you have both starch and fat), or be detrimental (e.g. if you get fat in your egg whites), or show different behavior depending on ratios (you can make hot protein-based foams with milk, but if you remove its water to make cream, it is only suited for cold fat-based foams).

The way you foam your food also matters, some liquids will foam with beating, others will require a siphon. Also, some foams are stable for a long time, others have to be served immediately before they liquefy again.

All in all, foams are a very complex topic, and for any given liquid that comes across your way, it is unlikely that you can just pick it and make it into a mousse. If you want to create foams, use a recipe, these are tested to work.

rumtscho
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  • That's a great diagram; trust a great chef to come up with something so simple, yet so great. – bob1 Apr 20 '21 at 20:26
  • I don't understand the diagram. It seems to be saying that *gelatina* (gelatin) and *grasa* (fat) are both appropriate for a foam which is *fría* (cold), *fécula* (starch) is appropriate for one which is *caliente* (hot), and *clara* (egg whites) is appropriate for either *fría* or *caliente*. But then where do *dulce* (sweet) and *salado* (salty) come in? Presumably *dulce* and *salado* aren't just there for decoration, so the diagram must be saying something about them, but I have no idea what. – Tanner Swett Apr 21 '21 at 17:21
  • Initially, I thought that maybe the intention was that you look at circles that are arranged in straight lines: for *dulce* and *fría*, use *grasa*, and for *salado* and *fría*, use *gelatina*. But that's inconsistent with the fact that *fría* is connected to *clara*. (Not to mention that I'm pretty sure there's nothing wrong with a sweet, cold, gelatin-based foam.) – Tanner Swett Apr 21 '21 at 17:23
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    @TannerSwett I read the diagram as simply descriptive, stating which foam kinds are possible (or maybe which ones are being made by Ferran Adria). So, if you choose one circle per column and there is no line connecting the three, that kind of foam is not recommended. There are only three lines missing for the pairings (three-tuplings?) to be complete: no hot gelatin (check: would melt), no hot fat (check: melts too) and no cold starch (unsure why, maybe it is simply not considered tasty). – rumtscho Apr 21 '21 at 21:14
  • @TannerSwett In addition to rumtscho's excellent comment: Yes, _dulce_ and _salado_ are just there for decoration. They're connected to both hot and cold, so either can be either; it's redundant information, although perhaps useful if one is starting from a place of "I want to make something sweet" and making other decisions from there. sweet-cold-gelatin is connected, and thus there is indeed nothing wrong with it. – Matthew Read Apr 21 '21 at 21:20