Fat Bomb - Keto Custard Recipe and variations


The Living Force
FOTCM Member
I've been experimenting with an egg free version of this recipe on and off for a few months (with quite a few disasters).
I've managed to get consistently good results for the last 4 batches (using different types of butter), so I'm pretty sure I've got a consistant recipe for others to try now.
I tend to make a large batch, but the numbers could be divided and should still work ok.

1kg butter (or other fat)
8 heaped (or 16 level) tablespoons of sunflower lecithin powder
Gelatin (enough to set 1 liter of water)
400ml of water
5 heaped tablespoons of xylotol or whatever you prefer (adjust to for taste/preference)

Optional (for preservation if keeping it in the fridge for more than 4 days)
1 tablespoon of honey (preferably local/thick)
50mg of lugols iodine

In one small saucepan add the water, and heat (as instructed by the packet) to dissolve the gelatin.
Add the sweetener as well.

In a large saucepan, melt the butter/fat, but do not get too hot.
Stir in the water with the dissolved gelatin/sweetener.
Stir in the honey at this point if you are using some, and make sure it's fully desolved.

Make sure the mixtures temperature is about 40oC maximum! This is important. If it's too hot allow it to cool.
With a manual hand whisk, stir in 2 heaped (4 level) tablespoons of sunflower lecithin powder.
Continue to stir until it is fully dissolved (~4-5 minutes).
Repeat the above steps until you have added 8 heaped (16 level) tablespoons of lecithin.
After some mixing it should now be a thick custard!

Cool as described in earlier recipes (add the saucepan to sink with cold water in).
Add the lugols if you so wish.

If you want to add some fruit at this point, you can do so. Use a hand blender being careful not to make a mess.
Pour into containers and store in the fridge (freezing will break down the gelatin). The lecithin will continue to thicken the mixture over the course of an hour or so.

One of the advantages of this version of the recipe is that it is much easier to make. As long as the temperature doesn't go over about 45oC the lecithin powder will continue to emulsify the mixture. It also works better if not dissolved in water first. The powder should work at temperatures as low as 25oC too, so I usually aim for 35oC - 40oC for the mixture when adding lecithin.

Here's the brand I'm using:

So why the optional honey/lugols?
I have noticed that sometimes goats butter upsets my stomach. It doesn't upset my stomach if it's cooked.
On the hunch it was probably bacteria or something similar in the butter (and because we are not heating the mixture enough to kill things) I added the honey and lugols. This seems to work for me, and I've had no issue with upset stomachs when using goats butter.


The Living Force
Interesting, I would have thought of using cultured butter to help with preservation. Perhaps that would be useful for people who aren't so sensitive.


The Living Force
FOTCM Member
Adding one minor update to this - I've just tried following my own recipe and it failed to emulsify! The first time this has happened since lowering temperatures.
A teaspoon of cold water didn't help. Wracking my brains I recalled vanilla essence tends to contain alcohol - so as a last resort I adding a dash of spirits. This acted as a catalyst and the mixture emulsified and became super thick within minutes of stirring.
So if anyone has tried this and is still unable to get it to thicken properly, this may be what is needed.


The Living Force
If you want go go down the rabbit hole you can look up HLB guides for emulsions. To emulsify two substances, you must add a 3rd substance with an HLB number matched to the HLB number of one of the substances. Which substance you match determines whether you get a water-in-oil emulsion or an oil-in-water emulsion. The former are much harder to achieve.

I'm not sure, but I think alcohol has a low HLB number, whereas the HLB of this emulsion is around the same as the emulsifier used - Lecithin. This is a high HLB number because it is an oil in water emulsion. Therefore alcohol will lower the HLB number of the lecithin. This suggests that the lecithin may have too high HLB. But I'm not sure about this since the role of alcohols in emulsions is not something that is talked about often.

This is an odd situation because normally alcohols increase the solubility of oil in water (or vice versa depending on which specific alcohol), which is counterproductive for emulsions because the incompatibility of the liquids is what allows the emulsion to form.

In any case, the idea would be to look for something with a low HLB number that you can substitute for alcohol.
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