Great stuff JD!
It sounds to me as though you're not quite doing a double regular MaxiBIAB here, but a thicker mash (in a tun?), over- gravity boil, then post- boil dilution?
I had a squiz through your adapted spreadsheet, there's the top up addition to the kettle (C20), that should be sparge and not a dilution water addition, right? I need to know more about your setup and process though, but it looks like you've adapted MaxiBAIB to stock BIAB for a double batch.
Some parameters (i.e. efficiencies) are less than predictable, so with MaxiBIAB I've used the full vessels (commonly available) at mashing and sparging, then any slack in efficiency gets taken into account with post- boil dilution to a pre- determined OG. Sometimes the final volume may come in under, sometimes slightly over, but the one fixed parameter is the OG, that's what I like about this method- shouldn't miss the OG target with MaxiBIAB. This comes at the expense of variable diluted volume in the fermenter, but OTOH it is attractive to novices by keeping volumes simple by using full vessels. Well, that's the theory, anyway!
Post #26 made 7 years ago
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