Soy Lecithin In Chocolate: What It Does And Why It Is Declared

Soy lecithin in chocolate is an emulsifier, added in fractions of a percent to change how the molten chocolate flows. It is declared on an ingredients list as "emulsifier: lecithins" or "soya lecithin", it is typically used at around 0.5% by weight, and its job is rheological rather than anything to do with taste.

The interesting part is not whether it belongs in chocolate. It is that a half-percent ingredient does more to the handling of a batch than almost anything else in the recipe, and that the published measurements of what it does are less flattering than the category assumes.

What an emulsifier actually changes

Molten chocolate is sugar and cocoa particles suspended in fat. Its flow is described with two Casson numbers: plastic viscosity, how thick it runs once moving, and yield value, how much force it takes to get it moving at all. Both matter in production. A moulded button needs a low yield value so it fills the cavity.

Ashkezary and colleagues measured all of this for the Italian Journal of Food Science in 2018, testing emulsifiers in a reduced-fat dark compound chocolate at two refining times. They compared lecithin at 0.5% and 1%, citrem at 0.5% and 1%, and PGPR at 0.25% and 0.5%. The paper does not specify that its lecithin was soy-derived, which is worth noting before the numbers are read across.

Read the two columns against each other and the trade-off is visible. Lecithin at 1% pulled the viscosity down from 18.74 to 14.89 Pa·s, but pushed the yield value up from 16.92 to 29.37 Pa. At 90 minutes of refining, lecithin at 1% reached a yield value of 66.09 Pa, the highest in the study. Citrem at 0.5% and 60 minutes gave the lowest at 10.23 Pa.

The authors conclude that citrem was the most effective emulsifier for reducing the rheological parameters they measured. PGPR could not be fitted to the Casson model at all because of a negative intercept, so it was analysed under a power law instead. That is one study, in one compound chocolate formulation, at a reduced fat level, so it is a data point rather than a rule for the whole category.

Why soy, and why it has to be declared

Lecithin can be drawn from soya, from sunflower and from other oilseeds. For anyone avoiding soya, the labelling position in Great Britain is unusually clear.

Annex II of Regulation (EU) No 1169/2011, retained in GB law, lists the 14 allergen categories that must be emphasised in an ingredients list. Item 6 is "Soybeans and products thereof, except" four named carve-outs: fully refined soybean oil and fat; natural mixed tocopherols (E306) and the related natural D-alpha tocopherol forms from soybean sources; phytosterols and phytosterol esters derived from soybean vegetable oils; and plant stanol ester produced from vegetable oil sterols from soybean sources.

Soya lecithin is not on that list of exceptions. So it is declarable, and it must be emphasised in the ingredients list of a prepacked food sold in Great Britain. If a bar contains soya lecithin, the word soya appears, by law, in bold or an equivalent treatment.

The real problem with soy lecithin in chocolate

It is not toxicity and it is not the soya. It is what the word "emulsifier" conceals. An ingredients list that reads "emulsifier: lecithins" does not tell you the source, the inclusion rate, or whether a second emulsifier such as PGPR is doing the heavier lifting alongside it.

There is also the question of what the emulsifier is standing in for. The Ashkezary study ran on a reduced-fat formulation, which is the usual commercial reason to reach for one: an emulsifier buys flow that would otherwise have to come from fat. A chocolate made with enough cocoa butter to flow on its own does not need the help. Neither route is dishonest, but only one of them is visible on the front of the pack, which is the same gap we describe in how to read a food label properly.

Sunflower lecithin, PGPR and the alternatives

Swapping soya for sunflower removes an allergen declaration. It does not remove an emulsifier. That distinction gets blurred in a lot of clean-label marketing, and it is worth keeping straight when you are comparing two ingredients lists, as in our line-by-line look at a cacao ingredients list.

What's actually in a Chaski tube

Chaski is a 600 g tube of dark chocolate buttons at 77% cacao, made from single-origin Peruvian and Ecuadorian cacao with coconut sugar, Lion's Mane as a fruiting body extract and Cordyceps sinensis mycelium. There are no emulsifiers in it at all: no soya lecithin, no sunflower lecithin, no PGPR. There are also no seed oils, no palm oil and no added cane sugar, and the cacao is low-temperature ground.

That is a composition fact and we will leave it there. It is not an argument that emulsifiers are harmful, and we are not making one. Every batch is tested for lead, cadmium and pesticides, and the daily dose on the pack is four buttons. The full declaration is on the Chaski Cacao product page, with the rest of our label and process notes in the Chaski guides library and the whole-bean question covered in how whole cacao and de-fatted cocoa powder differ.

Sources

1. Ashkezary M R, Yeganehzad S, Vatankhah H, Todaro A and Maghsoudlou Y, Italian Journal of Food Science, 2018, 30, 26-36
2. Regulation (EU) No 1169/2011, Annex II, legislation.gov.uk, 2011