Cream of tartar helps stabilize and gives more volume to your mixture. If you are looking for replacement go for 1 teaspoon of lemon juice. Keep in cool and dry place. These should keep for a couple of weeks in an air-tight container.
Very surprised how good these were. Had made a recipe using chick peas and a great way of using the water drained off. I did not have any rose water but put some almond essence in. Yummy. - 20 Mar 2017
Have to confess I was sceptical about aquafaba, but it is truly amazing. 30 minutes and brilliant egg free vegan meringue - 1 can's worth of juice made about 48. Definitely took the 30 minutes, but so worth it. have fooled family and friends so an absolute must Ready to try lots of Aquafaba recipes now. - 30 Mar 2016
I'm a believer!! These are so easy and fun to make. I didn't have any cream of tartar, so I used 1/2 tsp (total) lemon juice. The outcome was the most subtle hint of rose and a bit of a lemon aftertaste. I think these are a perfect amount of sweetness. I baked for two hours, then left them in until cooled. They came out light and crispy. They crumble easily but you can bite into them without them disintegrating. What a great recipe. Next time, I'm adding chocolate or dipping them in white chocolate... Thank you for sharing. - 15 Jun 2016 (Review from Allrecipes US | Canada)