Definitely make cider with the crabs. That’s great you have access to so much.
I make crab cider or wine most years - and have been meaning to write down the recipe but because I make it from memory ... and procrastinate ... I have not gotten around to writing down a concise recipe.
One thing I would suggest is to make sure for yeast you use 71B-1122. Crabs are unusually acidic and high in malic acid, and malic is very sharp in taste, 71B is a yeast that reduces malic acid levels during fermentation.
In general ...
I pick the apples as late as I can before the first hard freeze to allow as much starch as possible convert to sugars ... watching to make sure the apples do not start getting rot on the tree from being over-ripe.
I de-stem at least 80% of them ... but much larger amounts of apples I would suggest just picking out any leaves, twigs and rotten apples. Whether to de-stem has to do with the size of the apples ... mine are “ornamental” size, like a large cherry, so there is a high volume of stems per the volume of apple.
I’d wash the apples in a K-meta solution ... do not leave the apples in the solution for more than about 20-30 minutes (i.e. not overnight) or they’ll absorb the solution.
Drain and, I would suggest, freeze them (if you can) to make them easier to crush. Put the apples into 2-gallon size freezer bags and freeze them for about 3-4 days (this way you know they are frozen through). Take them out and thaw them.
Crush, grind or process them. Though it’s a bit time consuming a food processor will do for smaller batches ... just a few pulses will do ... I’ve also crushed with a sanitized 4x4 post (like you tamp down stone aggregate etc).
For much larger batches like you are considering you may try to find someone with a cider mill/crusher (such as a roller mill).
People have different creative ways to grind the apples ... some use a brand new garbage disposal like you use on a sink (you can google that conversion) ... but while that may work with larger apples, with all the little stems on small crabapples I think it might clog if the apples are not mostly de-stemmed.
There is quite a bit of info and vids on processing the apples if you google around and check youtube.
Although I have the capacity to press a huge amount of apples without problem (my largest fruit press is a ratcheted 59 liter/200lb capacity model) I do *not* press the crabapples.
I ferment the milled apples on the skins & flesh ... and the enzymes and yeast very substantially reduce the pulp to being mostly incorporated into the must. Much easier and I find gives better flavor & color. You have to use the pectinase however when fermenting like this.
I put the apple pulp & juice in the primary fermenters (32 gallon Rubbermaid Brutes) and add just enough “warm but not hot” water, to cover. Add the pectic enzyme ... I use approximately 2 tablespoons of pectinase per 5 gallons of pulp/water. Let sit overnight, stir occasionally. Then, continue as normal, chaptalize etc.
If I am picking them somewhat earlier in the harvest season I'll also use a dose of amylase as well ... an enzyme to convert the starch. Not always necessary, but I usually do it anyway.
A final suggestion when picking all those small apples ... I am not choosy as I grab them by handfulls and put them in the bucket (I use 5 gallon buckets) ... only the ones that are really horrible I avoid grabbing. Then, when I do the “picking-them-over” while seated I sort the undesirable ones and twigs, leaves etc from the one’s I’ll use.
Labor intensive but provides a great product.
