BeerBorg

Craft Beer and Brewing has a short, concise description of BIAB brewing. I agree with what is written except that I think it can be every bit as efficient as traditional brewing except once you need to go over say, 1.075, a little more work is needed.
For those interested in trying it, this article explains it as simply as possible.

There are other ways around the drawbacks they've outlined, also. I use a homemade MLT for my five-gallon batches, but for my 2.5 gallon batches, I prefer BIAB.

I already have three kettles that I use in my brewing; a 3-gallon, a 5-gallon, and an 8 gallon. For BIAB, because I'm using a smaller volume of grain (usually about 5 pounds or so), I can mash in the 3-gallon kettle, calculating 1.25 gallons of water per pound of grain. Yes, this isn't a full-volume mash, and here's where my technique departs from traditional BIAB. I mash for an hour in the 3-gallon kettle, drain, squeeze the bejabbers out of the grains, and then sparge in the 5-gallon kettle, making up the pre-boil volume.

This helps my efficiency, I believe. It's always seemed to me that not sparging leaves more fermentable sugars behind than I care to, and I want all that I can get out of my grains. When I use my MLT, I do two sparges, and while the runnings get lighter and lighter in color, there's still something rinsing out, so I feel I'm not wasting my time. Same with the single-sparge BIAB. Any discrepancies between projected OG and actual OG are, I feel, a matter of my volume, rather than the actual efficiency of the process.

Good article, though. Makes it very simple and straightforward for someone who wants to investigate the technique.

I'm fine stirring every 15 minutes but with a pump I now reticulate. I find stirring and squeezing really help but if you want to go over 1.080, you may likely need to just sparge.

I do stir halfway through the mash, which is something I don't do with my MLT. But then, I do two sparges with the MLT, and stir each of those. And most of my beers don't go above 1.060, whatever technique I use.

I had been stirring every 15 minutes. Last two batches, I've just let it ride. As long as I mash out, I've gotten the same, or better, conversion. Then again, could be my new bag too.

MrBandGuy wrote:I had been stirring every 15 minutes. Last two batches, I've just let it ride. As long as I mash out, I've gotten the same, or better, conversion. Then again, could be my new bag too.

You seem to be getting good results, and when that happens to me, I don't necessarily try to figure things out. I just accept it, thank Ninkasi, and keep on brewin' beer.

Well, that's a little flippant; the more we understand about our process and the results we get from them, the more consistent will be our results. I just try not to over-analyze, and I certainly don't lose any sleep over it.

I'm satisfied with my BIAB efficiency now. I double crush my grains, do a 90 minute mash, mash out and then sparge to hit my pre-boil volumes. I've had no trouble getting 10 gallon 6% ABV batches doing it this way.