I guess I might have asked what everyone has on hand if they aren’t buying for recipes?
Personally - I got my grain inventory down to a part-open sack of Maris Otter, and that suits me just fine. As long as I have a couple of kg's of Otter in the sack then my "spontaneous" brewing needs are covered, as I always have some packs of new hops to try and yeast to test (and more yeast in the bank, and backup packets of dry yeast) and an Otter SMASH is a good way to test them. Plus my default beer in the pub is generally a 4-4.5% golden ale, so it works as a house beer even if sometimes it might be less hoppy with a European hop, and other times it will be super-hoppy.
Otherwise - it's good to plan. It doesn't have to be in super-detail, and obviously there's scope for the odd spontaneous brew, but I've got a pretty good idea what my next 4-5 brews are going to be and that makes it much easier to organise purchasing without tying up cash in grain that is just sitting there getting stale. Also this :
it may be a good idea to start with certain style and master it by brewing a couple of batches before moving on to the next style. A good principle with malts could be the KISS principle because too many factors in a recipe mean too many ways to go wrong.
KISS is definitely a good idea - I think it's a common mistake for homebrewers to overcomplicate things by having three different crystals etc in a beer. And +1 to actually trying to master a single style before moving on, or at least, having 2-3 styles that you're trying to master whilst giving yourself a bit of variety to drink. It's easy to get distracted by "stuff" when it's process you need to worry about.
I completely understand the kid-in-a-candy-store aspect to all this, but at the same time - how many gallons are you
actually going to drink of that fenugreek-and-strawberry quadrupel? For now I'd let the bottle shop provide your "minor" beers whilst you focus your brewing on really
nailing a house beer or two. Not only will it leave you with lots of "usable" beer, but the experience will improve all your other brewing.
I brew IPAs, NEIPAs, and Cream Ales. I will be getting 10# of flaked corn for sure. Should I be getting Munich, Vienna, some crystal, biscuit, honey, white wheat, carafoam...ahhh so many choices I don’t know where to start.
I am newish to All Grain and am still learning what malts I like. Maybe I should buy 5# of a handful of different malts and just brew.
I'd start with what beers you like - and of the ones you mention, I'd start with the "ordinary" IPA, then the cream ale, then the NEIPA. Find a recipe for each of those that is roughly like something you know you like, and buy what you need for those. Trialling grains is a bit of a pain compared to hops and yeast, where you can brew up a single big batch and then split it into different fermenters with different hop teas/dry hops/yeasts. Pretty much all my brewing these days divides a big batch into gallon buckets with different treatments.
You can test grain just by chewing a few, or making them into biscuits. But I guess you could set up a waterbath (ie only one temperature to control) with several ideally chemistry beakers but bowls or flower vases or something with pale malt and the test grain, mash them, probably wouldn't even need to boil them since you're not keeping them long - have a taste, then decant into soda bottles or something, perhaps with 30IBU of alpha extract or bittering hop tea just to be a bit closer to what your tastebuds are used to, then a splash of starter and ferment. Tighten up the lids before OG, and you've got yourself a reasonably fair test without too much work.
But really, I wouldn't go too mad with buying lots of speciality grains at this stage.
