Buttermilk.

hohee, Aug 24, 6:39am
Does any klind person know how to make your own and can you use plain sugar instead of castor! Thank you.

aly5, Aug 24, 7:47am
I read somewhere that you can use 1 T white vinegar or lemon juice with 1 C milk, let it sit for 10 minutesas a substitute. Re. granulated sugar vs castor- yes you can. Castor is finer therefore will dissolve while beating it more quickly than granulated sugar.Then again it would depend on what recipe you're making which is preferable.

m41, Aug 24, 7:51am
just the ammount of buttermilk needed for recipe like 3/4 c then squeeze lemon juice in mixing as it curdles then stop :) is what we do in the trade cheaper .