Im making Berry Gummies for my kids and most DIY recipes dont use a preservative. The assumption is they will be eaten within the week so the fridge should be fine. I want to make a larger quantity and possibly ship some. At looking at some basic gummy ingredients it looks like they may just be using Citric Acid? Is this a good enough preservative and at what % or measurement do I use? I saw a site that mentioned .05-.1% to 16oz of water? Does this sound right?