Probably the ratio of sweet cream and vanilla to cold brew. The standard pumps of vanilla are 1-2-3-4 for tall, grande, venti, trenta, so you get one pump of vanilla for every 12, 8, 13, and 7.5 ounces in your cup, respectively. However, the grande and venti cups have the same mouth size and you add a similar amount of VSC to both, so it’s going to be sweeter and have more VSC in a grande than a venti by standard. While a trenta should have a higher vanilla ratio, and more sweet cream. A trenta is almost twice the size of a grande and has a similar ratio of drink size to vanilla- but I’m almost certain it doesn’t get twice the sweet cream. I know the standard but not the exact amount it ends up being, but I really don’t think it’s twice as much- meaning the trenta would have a lower amount of sweet cream per cold brew, making it less creamy and not as sweet.

I feel like it's all about ratio, venti iced gets 2 more pumps than a grande so why does a venti cold brew only get one more. 1-2-3-4 doesn't make sense it should be 1-2-4-5