What are your units there? 24.4 brix to 17.5 brix is hardly any fermentation at all. If that's correct, I'd say you mashed at WAY too high a temp and got ZERO conversion and only pulled out what sugars were in the crystal malts you used. More info is definitely needed.
I can't be arsed to keep up this list of what's in the fermenters, but hey, check out the cool brewery I own!
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