adjusting for skipped sparge

Im planning to try an experimental imperial stout. Its going to be really small (1.5 gal) but Im shooting for 1.100 OG. I have a plan, but Im wondering if I have the details straight in my head.
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SO,
If I rock a really thin mash----> decoc (gallon or so) to bring mash temp to 168 (and reach my preboil volume minus grain absorb. loss), effectively combining mash and a mini batch sparge... what changes do I need to make to the recipe?

can I just drop my eff. a little, maybe to 55/60%?

suggestions?

thoughts?

Yeah, that sounds fine, though I'd be surprised if you went all the way down to 55%. Especially if you're not particular that it be _exactly_ 1.5 gallons, you can just let it rip and then adjust with water in your kettle.

For a big beer like that AND no sparge, you probably should drop your efficiency quite a bit. Although, doing a bit of a decoction should help your efficiency somewhat.

would 60% be a good number for planning grain weight?

HItransplant said:

would 60% be a good number for planning grain weight?

Click to expand...

Tough to say, but it sounds reasonable enough. I think your best bet, though, is to just run your mash assuming 60% and then add water or boil to hit your target gravity.