I was listening to someone talking about challenging what can be done with kettle souring and I found it fascinating. They mentioned a key lime desert sour that they'd made and it sounded like it would be great. So instead of trying to copy that relatively sensible idea I thought I'd like to try an apple crumble kettle sour. So what I'm going for is something relatively light ABV, around 4% (though a boozy version does also sound appealing). Flavours I'm trying to trigger are apple, vanilla, cinnamon, oats, brown sugar, cream (crumble down here is a general term, it'll mean any or all of crumble, crisp or cobbler). Kettle sour will probably aim for about 3.8 - 4 pH. Thinking I'll use an underattenuating yeast to retain some sweetness. From the flavours above the apple should be the first one, then the others should support the beer. And lactose will probably get at least a small appearance (for that cream feel with the oats). Thinking about the apple flavour I remembered another hare brained idea I heard that appealed, a graf (https://www.homebrewersassociation.org/how-to-brew/how-to-make-graf-a-cider-beer-hybrid/). So I'm thinking I may put in apple juice (or concentrate, but if I'm going to the weird side, why not 50% apple juice). I'm using apple juice here to mean either filtered or unfliltered juice, cider is the name we use for the alcholic stuff. So how would you use the recipe builder to add in a large amount of a liquid with fermentables? Add it as a weight with a certain PPG and just remember to substitue some of the water as apple juice which I'd plan to add to the fermenter at the end. Probably not that fussed about overshooting the ABV by screwing these calculations up, just more interested in not under or overestimating the flavour contributions. Or it may be better as a recipe for the non-apple juice half and just get a gravity reading on the apple juice to know how much it's going push the ABV up or down? Havent thought too much about the cinnamon/vanilla additions. Probably steep it after fermentation in a hop bag. Lactose will be added to taste at packaging. Also thinking I'll ignore the hops and rely on the lactobacillus to balance the malt flavours. Recipe is here - https://www.brewersfriend.com/homebrew/recipe/view/779681/apple-crumble I'd love any thoughts on things I may have not considered or holes in my thinking (and I'm sure there's a few).