I love coffee, but I find that usually when I pour soy milk into my coffee, it separates or curdles in some way and becomes utterly vile.
Do any other non-dairy milks or specific soy brands produce better results? Or should I heat it in some way? Presumably Starbucks knows what to do, as the lattes they serve don't look like the ones I make.
To re-state: How can I make a vegan latte without the milk curdling unpleasantly?
You want a milk that doesn't curdle, and that produces foam. That's soy drink and pure rice drink (doesn't froth) off the list. Fortunately, there are a lot of alternatives.
Almond drink, hazelnut drink, cashew drink and other nut drinks are excellent and produce great foam, although some brands may curdle with some coffee. The best option is then a mixture of e.g. hazelnut and rice drink.
Many hazelnut drinks (Alpro) have already rice added, and sometimes Carragenan, which is then not such a good choice. But there are other brands (e.g. Provamel) that have pure nut drinks, and you can mix them with rice drink or oat drink to your liking. There are even brands like Natumi that have a perfect mixture of hazelnut with rice, or almond with spelt, that doesn't curdle and produces great foam.
Also: Don't use filter coffee! It tends to be more acidic than espresso, and the acid is what mainly causes the curdling.
I find that grain milks behave especially well for me for making milky drinks. I make latte (and masala chai) with buckwheat milk, millet milk or rice milk.
For latte I preheat the milk (in a saucepan) and I've never had any curdling or other weird issues doing it that way, even if I accidentally leave it until it boils.
My mum uses Koko coconut milk to make a milky coffee, and that never curdles even when added directly from the fridge.
Try to look for vegan milks for baristas. One such milk is the Oatly Barista with which I have had great results. For that matter, any oat milk would presumably do fine.
I tried foaming quite a few Alpro milks and the best results I had were with the Coconut, Rice and Almond.
It is quite possible that the soy milk you are using is simply not good for lattes. It also sounds like you're pouring your milk into coffee as opposed to steaming and foaming your milk and then pouring over espresso shots, which is a big difference!
There are special soy milks that many cafes use to help deliver the perfect latte.
For example, this barista series from Pacific is:
Specially formulated to withstand high temperatures and deliver consistently smooth, velvety microfoam. It performs as well as (or even better than) dairy – perfect for latte art.
Personally I have found that pouring my nut milk into my coffee cup before the coffee is made and letting it warm to room temperature helps prevent any separation.
