If I do a 30 minute vigorous boil instead, my batch sparge water drops low enough that I would probably just add it to mash-out. What efficiency drop would I expect from 'no sparge' and from short boil?
With a low gravity beer in the 1.036-1.038ish range I'm planning on 2.25-2.5 qts./lb. which is way thinner than the 1.25-1.5 qts./lb. I normally do. I've read that once a mash gets 'too thin' the required mash time goes up; is a 40minute mash possible at 2.5 qts./lb.?
There has been quite a few posts on shortening brewing steps lately that really has me desiring shortening what I can. Especially since moving to these hop-steeps long ago which have great results, but also add time. Especially when brewing in the evening and finding myself pitching at midnight or later sometimes.
No-sparge brewing will reduce your efficiency substantially. I would say it's down to about 55% for a regular strength beer, and maybe a bit better around 60-65% for a small beer around 1.038.
2.5 qts/lb is no big deal at all. You'll still get sufficient conversion, efficiency & attenuation, mashing at that ratio for just 40 minutes in my experience.
Glad to hear I'm not the only one anymore interested in saving time. Cheers!