Why was there not enough foam in my garlic foam with soy lecithin?
Just an idea... I've had problems making foam because of hard/basic tap water (a lot of chalk in the water) - making frape though, not garlic foam:) Foam will more easily form in soft water as you can easily test with a piece of soap. If you have hard tap water you could try using boiled water (some of the chalk in the water will react and leave a residue on the bottom of the pot) or bottled water with pH 7 (neutral). Another idea would be to add just enough acid for neutralisation but I imagine that could be a bit tricky and you'd risk the milk curdling so I wouldn't recommend it.