Thickening agents in gelato custard

Eggs or gels in Gelato?

Is one method of thickening gelato custard more sustainable than the other?

My gelato has no eggs. Many ice cream recipes call for egg yolks, which function as emulsifiers in ice cream, keeping water in a gel (making the ice cream smooth and not icy) and increasing the ice cream’s ability to hold air when it is churned. Butterfat in cream also holds air once ice cream is churned.  Air translates on the tongue to the sensation of creaminess that we all love in ice cream.

In order to make ice cream, you need to add a gelling agent like egg yolks and some cream.  At Chanterelle, the restaurant where I was the pastry chef for ten years, I spun three flavors, a gallon each, every day.  I went through a case of eggs (360 to be exact) in around four days.   For each quart of dairy (usually at a 1:1 milk to cream ratio), I would use 8 egg yolks and often would have nothing to do with most of the egg whites.  They would end up in the garbage.

Have you ever taken care of chickens?  It takes a lot of feed, tending and cleaning to get them to lay 8 eggs, especially if you are going to raise them sustainably and permit them to roam outside. Then you have to collect, clean, store and refrigerate the eggs.  You have to package them so they don’t break.  And, then, you still have to transport them in refrigerated trucks and trains in a timely manner because they have a limited shelf life.  That’s a lot of work and a lot of energy, often involving extensive fossil fuel use.

At this point in my career as a chef, after so many years of working with countless raw ingredients, I have had time to reflect on how much energy goes into producing them.  When I started scaling ice cream recipes for my pedal powered bike, I decided I wanted to make ice cream without egg yolks and instead, use ingredients that have the same effect but require less energy to produce, store and transport.  

I began experimenting with gelling agents, which appeared to me to have less of a negative environmental impact to grow, store and transport.  After endless tests and reading extensive literature about the numerous gelling and thickening agents on the market – guar gum, kappa carrageenan, locust bean gum, xanthan gum, agar, chia seeds, cornstarch, tapioca starch, arrowroot starch, rice flour (to name a few) – I settled on a mixture of rice flour, locust bean gum and xanthan gum to make my ice cream creamy.   Where in the past (at all the jobs I pastry “chefed”) I would have used 24 eggs (approximately 28 tablespoons of egg yolk) in a small batch of ice cream base, I now use ¼ teaspoon of xanthan gum (a byproduct of the bacteria, xanthomonas campestris, when it consumes starch), ¾ teaspoon of locust bean gum (powder of ground seeds from a carob pod on a carob tree), and 3 tablespoons of rice flour (finely milled rice), all ingredients that are shelf stable (they keep for at least a year and don’t need to be refrigerated) and are used in such small quantities comparatively to eggs.