I use oat flour + protein powder as a mass gainer, it's way healthier, cheaper and more natural.
1 cup rice drink, 1 cup juice, 1 cup oat flour, 1 tbsp protein powder!
Do you know the carb/protein ratio of this drink? How many calories usually? I use soy milk in my drinks for the additional calories.
1 cup of instant oats (120g) + 1 scoop of protein powder (30g) + 1 glass of rice milk (200ml) = 98g carbs, 40g protein, 10g fat and 650 - 700 kcal.
When you do it with soy milk, it's about 80g carbs and 45g protein.