BIAB vs Cooler Tun

Just finished up my first try at BIAB.I brewed an ale I have brewed before to compare. What I noticed is I used less water I calculated the absorption rate the same as my cooler setup.i was off by 1 gallon. No problem since I did a little pour over type sparge so was able to get what I wanted. I reached my same FG so that was good. I was able to hold the temp of the mash water in 30 deg weather another concern satisfied. It took a little less time because of the no re circulation or mash rest. One less thing to clean. For 5gal batches and under I would definitely do it again. In the warm weather when I do double batches and party gyles ill use the MT.

So you were trying to do a full volume mash BIAB but came up 1 gallon short? You have to let it sit for a while to drain and/or twist the bag tight and give it a squeeze. I always do a pour over sparge too.

No. I must have calculated my total water wrong . I ended up with a gallon of water left. I saved out 2.5 gallons to sparge and only used 1.5. I like doing the sparge so I can get the end volume I were right D I didn’t lose much heat at all.

Brew Cat, just out of curiosity, what was your efficiency? A friend and I were doing side-by-side batches the other day and he was doing BIAB and I was mashing in my MLT, he ended up with about 50% efficiency and I was up at 75%. Same grain bill, same water treatment/temps.

According to brewers friend I got 75%. 50% sounds low you sure that is correct?

I used a recipe I’ve brewed before for comparison and the efficiency of both were similar . That was one of my major concerns about BIAB.

Yeah, they checked multiple times with temp adjust and let a sample cool. I think their temps were way off throughout the mash with lots of fluctuation. At one point they realized they were low and fired up the stove and within a few minutes it was approaching mash-out temps so they cut it off. They were not psyched but had also done almost no research. How do you monitor temps for BIAB? floating thermometer?

I put a 1" piece of styrofoam for the lid and just poked a thermometer through it. I heated the water to about 170 then shut off the heat. Wrapped it in blankets and put on the styrofoam lid. And let everything warm up just like doing it in a cooler. Dough in at 165 and hit 152 my mark. Don’t open it up to peek. Only dropped off 2deg after the hour. Stayed at 152 most of the mash.

Most people on this forum that talk about BIAB are actually doing a modified BIAB (with an added rises step). Traditional BIAB has no rinse step and gives the same kind of efficiency as a no-sparge mash, so 50% sounds a bit low, but still in the ball park.

I did do a pour over mash which I heard would be like a fly sparge. Maybe that was the difference.

This^^^ I’ve only done a couple of BIABs and didn’t rinse/sparge them but I calculated my recipes at 60% efficiency and came within a couple points of that.