Abstract: Ganache is delicious, but not everyone eats dairy. We examined whether coconut milk can be used for the creation of a non-dairy ganache. We ran a series of experiments. The answer is that, with some creative techniques, you can use it, but it does not come anywhere near to the real thing.
Introduction. Someone wrote a question on Seasoned advice about coconut based ganache and we got curious.
Background. We love ganache even more than pure chocolate, and make it often ourselves, so we think we have all the prerequisites needed to create and judge a coconut based ganache recipe. Our favorite ganache recipe 1 (which we used as a starting point) is: 100 g chocolate, 72% cocoa (only made from cocoa, sugar, and cocoa butter, no vegetable fat or emulsifiers); 100 g cream, at least 30% (non-UHT), 25 g butter.
Method. We prepared the base mix as follows: 25 g coconut milk were heated until boiling. They were removed from the heat. 25 g chocolate (72%) and 6g cocoa butter were added. Everything was left to dissolve. After 5 minutes, the mixture was whipped with a handheld mixer at the second-to-highest setting. This was Version 0. It was divided in two batches. Different versions were made from each batch by gradually adding guar (a knife-point-ful), egg yolk (1, in lieu of lecithine) and sugar (8g per batch). Each version was whipped for at least 3 minutes. The final versions (1c and 2b) where put for 30 min in the refrigerator, then taken out and whipped again. As there were no observable changes after the cold whipping, we do not treat them as a different version. We also made a small portion of dairy ganache for comparison purposes.
Results. These are listed in Table 1. The numbers in the ingredients columns of the table represent the order of adding the ingredients to the mixtures.
Table 1. Experiment results.
The final consistency of version 1c is documented in Figure 1. Note that the peaks do not drip and you can rotate the bowl at 180° without anything falling out. The piece of chocolate was added for color comparison.
Figure 2 shows a zoom of the blue bordered area in Figure 1.
Discussion. It is possible to make a profiterole filling with coconut milk based ganache, but it isn't quite like the real deal. Also, it resembles non-whipped ganache more closely than whipped ganache.
The basic ganache recipe can be done with coconut milk instead of cream and cocoa butter instead of butter. However, it tastes fattier than real ganache, and it is runnier. Unlike dairy ganache, whipping does not result in aeration.
We think that eliminating the cocoa butter altogether will somewhat alleviate the fatiness problem, but we did not test this proposal yet.
A thickening and or emulsifying agent can improve the ganache texture. Even though egg yolk improves aeration, is not a good choice, as it results in a slimy feel. Guar is a better solution.
The addition of sugar ruins the chocolateness of the taste. If bitterness is not desired, a sweeter chocolate (50%) should be used. Only dedicated sugar lovers or Americans should resort to adding sugar. In that case, it should be added before the guar (we would suggest dissolving it in the coconut milk before boiling it) as not to interfere with the texture of the final product.
Threats to validity. First, there was a single tester (the quasi-royal we). Second, this tester is already biased in favor of dairy products in general and specifically for dairy based ganache. Third, many interesting combinations (including xanthan gum and corn starch) could not be tested due to lack of resources.
Conclusion and outlook. We found the experiment very inspirating. It was also yummy. But we'd like to issue an warning: This experiment is dangerous. In the preparation phase, we discovered a penchant for guared coconut water deep fried in coconut fat we'd rather not have known about. Nevertheless, we are looking forward to offering the results for peer preview to a chocolate-loving lactose intolerant co worker.
References: 1 My own recipe book
In NZ normal pure cream is close enough to "double cream" in performance, it's around 35% to 40% fat. By general global definition it should be called "heavy cream"
NZ cream is pure skimmed cream from fresh milk, and does not need thickening or other processing to produce excellent results as a whipped product, or for a thick cream additive in sauces or fillings
Cream can get a little seasonal just after calving time (Aug), but in general it's just perfect
The export variety is often labelled "Culinary Cream" and is 38% fat or higher. This is what many people around the world would consider NZ cream (other than NZ butter or AMF)
If you want closer to 50% fat cream, ask your local farmers for some raw milk and skim out the lumps of fat from that. Let the milk settle overnight and skim the cream from that. Then gently heat the fat lumps to melt and carefully mix into the skimmed cream. Not for the faint of heart!
NZ "Thickened cream" or "Mascarpone cream" is standard pure cream with a thickener like E1442 added, you can make your own too
Best Answer
This will work just fine. Many people will get the math wrong, but your calculations appear correct. Give it a good stir and everything should come out as expected. Most recipes are sufficiently tolerant that substituting the double cream would likely be fine compared to just using the heavy (if not an improvement).