Syrup+gelatin based foam not working

[Anonymous Modernist 19551]

I recently bought a 0,5L siphon to try (amongst other things) making some foams.

My first two attempts sadly have failed.

This is my last attempt:

1) Two sheets of gelatine soaked in cold water for 5-10 mins

2) 0,25L Monin raspberry syrup heated

3) I add the gelatine to the syrup while stirring and it quickly dissolves.

4) I then let the syrup sit until it gets to room temperature.

5) When at room temperature, I add the syrup to the siphon, close it, and load it with two chargers, shaking vigorously after each charge.

6) I then put the siphon on it's side lying in the fridge for about 5-6 hours.

When it came time to test the foam, nothing but gas would come out of the siphon. When I opened the siphon, the syrup had turned into a quite firm gel covered by what looked like a thin layer of foam.

I have a few theories about what could have gone wrong, but I'd like your opinion and advice as well, before my next attempt. After two failures, I need a success

My theories:

1) Too little syrup (0,25L for a 0,5L siphon) / roo few chargers. Maybe the pressure in the siphon was not high enough to push the gas into the syrup? Could more chargers have helped, or should I get a 0,25L siphon? (I would rarely be making foams from 0,5L fluid)

2) Should have shaked the siphon just before trying to eject the foam.

3) Too much gelatine, making the gel too firm for the gas to push it out.

4) Should the siphon be stored upside-down in the fridge? At least then the gas not in the gel, would be pushing the gel out, instead of just ejecting all of the gas leaving me to scoop out the gel manually afterwards

Any help will be much appreciated!

[Anonymous Modernist 310]

Hello Kenneth,

Welcome to this forum. You were on the right track with your theories. I'll take all your points and try to clarify them.

1) You can put less liquid in a larger syphon and it will work. The only problem is that you need to use more cartridges than if you had a syphon of the right size or a fuller syphon.

2) It's always a good idea to shake your syphon between the charges and before using it.

3) It's probably the main reason for your problem. For an espuma you usually need from .5% to 1.5% gelatin in your liquid. Supposing your sheets are 2g each you are really on the high side. Especially since the Monin syrup seem to be 2:1 sugar/water so it's already quite thick. So start with a single sheet and adjust from there.

4) It's not supposed to change anything. I store my syphons in the fridge standing up to take less space. It may give you some foam or it may block your syphon if your gel is too thick...

You'll get better gas absorbtion in colder liquid so you can cool it lower than room temperature. As long as it doesn't get firm. The gaz get into your mix because you said the top part of your gel had foamed when you opened the syphon so you're on the right track.

Good luck

Louis-Frederic

[Anonymous Modernist 19551]

Thanks Louis-Frederic!

It's good to know I'm on the right track. I'll make another attempt soon, hopefully with success