Week Twenty-Two: Dairy free

I’ve already made plant based ice cream, so I decided to use dairy free week to do something slightly different which admittedly does not really meet the definition of ‘dairy free’. I’m going to be making lactose free ice cream. My dad is lactose intolerant, which means he’s never tried any of the ice creams I’ve made. I’ve inherited a lot of my dad’s ailments, including an allium intolerance (unless you have it, you have no idea how inconvenient this is!) along with general allergies and other things I won’t discuss on the internet with strangers. But fortunately for me, I don’t seem to have lactose intolerance - it’s recessive, as long as I inherited a good gene from my mum, I’m fine. That’s rare, on a worldwide scale; it’s estimated that around 65% of the worldwide population is lactose intolerant, although there are wide regional differences with a higher incidence rate than this amongst East Asian people - in some communities up to 100% - and around 10% of the UK population having it. 

Up until around 7000 years ago, babies tolerated lactose because they produced the lactase enzyme, and as they weaned off milk the body’s production of lactase dropped and then they no longer tolerated lactose. Then lactase persistence evolved, a mutation that allowed for the continued production of lactase beyond babyhood. Or mutations, because there seems to be multiple genes potentially responsible. I’m not a geneticist and lactase persistence is a complex topic, but suffice to say there’s a high level of lactase persistence in Western Europe which generally reduces the further east and south you go, with an anomalous increase again in the Middle East. Whether populations which already had high percentages of lactase persistence learned to incorporate dairy foods in their diets, or whether populations were already relying on dairy foods and then being lactase persistent became advantageous is a chicken or egg situation. (My answer to that riddle is egg, by the way; it never specifies a chicken egg, and eggs predated chickens by hundreds of millions of years.) Either way, once you can rely on a reliable and repeatable source of food - a cow can be slaughtered once but milked over and over - then you’re going to get through famines much better, and in the long run your genetic line has a distinct advantage.

There are a lot of options for lactose free alternatives to creams and milk. I used the one my dad actually uses, which claims to be an alternative to single cream but it has 36% fat which makes it much closer to whipping cream. And we know what happens when you make ice cream from whipping cream only… I had to make some formulation changes to end up with an ice cream that is basically identical in composition to my normal custard ice cream, but using the lactose free cream. My dad is fond of two ice flavours, vanilla and butterscotch. Vanilla is easy to make - it’s 1.61% of the total weight in vanilla pods cut up and mashed into the sugar, and I've done it before - so let’s focus on the butterscotch here. Butterscotch is butter and brown sugar caramelised together. I decided to see what happens when I use light brown sugar instead of my usual caster sugar, and change the order of things a little. This is also the first time you’ll see me temper my eggs! It’s a process I don’t think is needed in most circumstances, so you may have noticed I just don’t do it, I usually put everything in the pan and heat it all simultaneously. But this recipe needs it because the dairy and the sugar is being heated first. If you don’t want to make this lactose free, just follow the method using my usual custard base to turn it into butterscotch (you also don’t need to use the ostrich egg in that recipe!)

Lacto-free butterscotch ice cream

Ingredients

(Use the percentages to make the amount you want; I made 800g)

353.52g lactose-free cream at 36% fat (44.19%)

166.32g light brown sugar (20.79%)

171.28g water (21.41%)

108.88g egg yolk (13.61%)

Method

1. Put the cream and sugar into a pan, and heat it whilst whisking constantly.

2. There will come a point where the mixture rapidly expands; when this happens, take it off the heat before it boils over and let it reduce again before repeating. I had it repeat 6 times but you could do more.

3. In a separate bowl lightly mix the egg yolk.

4. Take a small amount of the cream/sugar mixture, I used a 1/3 cup scoop about half full. Pour it into the egg yolk whilst whisking the mixture in the egg bowl, and repeat until about half of the cream/sugar has been added. At this stage, slowly pour the remainder of the cream/sugar mixture in whilst continuing to whisk.

5. Add the water and whisk it in fully.

6. Chill the mixture for several hours, preferably overnight; for best food safety check mixture is 20C before refrigerating and if it isn’t cool in an ice bath first.

7. Rewhisk prior to churning and strain the mixture.

8. Churn according to your ice cream machine’s instructions, stopping at soft serve texture.

9. Put into a container and freeze for at least four hours, preferably overnight.

(Apologies, I forgot to photo it before tasting it - I was just that keen!) The texture of this is beautiful, slightly stickier than my usual ice creams but I strongly suspect that’s the sugar type and caramelisation rather than the lactose free cream. There’s a light butterscotch taste, I think I’d like to make this again using dark brown sugar and let it do more expand/reduce cycles, maybe 10 rather than the 6, and see if that brings more of the flavour out. I think it will, and then it’ll be even better. But it’s already good, and I’m pleased I’ve worked out how to make ice cream for my dad.