Having problems with BIAB eff

I just finished up my second BIAB AG today, an Amber Ale, hopefully to be similar to Fat Tire. I am having a little bit of trouble getting my efficiancy up. I am currently getting about 65%, I know this is not horrible, but I would like to be up in the 70's. I'm pretty sure how I messed up the first AG, but I've got a few clues about this one.

The batch today was:
10# American 2-Row (ries)
.5# Belgium Special B
.5# Caramel 120
.5# Munich 10

Before I started, I requested my grains double crushed at the store, but I don't know for sure if they actually did it, so I took the bag and crushed it farther with a rolling pin. I mashed for an hour shooting for 152. After Mash In, I lost a few degrees over the hour. I ended up at about 148 at the end of the hour (keep in mind that I don't have the best thermometer to guage the temp, my "high" dollar temp gauge was way off). After draining and squeezing the hell out of the bag I took the tube's worth for the reading and cooled it down to take the reading, all while bringing to a boil and continuing with the brew.

My preboil gravity was 1.043 which came out to 65.4%. AFter boil my gravity came out to 1.048, recipe only called for 1.046, so I was over, but I also added 1# more 2-row to make up for no sparge.


So my question is do you guys think I was more likely to loose the efficiancy do to the temp loss and probably not the right temp in the first place, or is it because of my grain crush. I had quite a bit of power in the bottom of the bag, but I am not 100% sure what fully crushed grain should be.

 

65% for your second BIAB isn't bad. Did you stir the grain during the mash? Did you do a mashout at the end of your mash? Both of these will help efficiency and so will a very fine crush.

Post picture of your grain crush if possible.

 

I would try a mashout of 170 for ten minutes

 

These three things could help I think.

1. Your own grain mill to control the crush
2. Mash for 90min instead of 60
3. I mash with 4gal and sparge in a separate pot with an additional 11 quarts(don't know how much that helps but I can't fit enough water in single pot so I let the grain bag sit in the sparge water for an additional 20-30min before I wring it out)

My efficiency went from mid 60's to the low/mid 80's(from doing #'s 1 and 2)

I also had my LHBS double mill before I got my own mill set-up and it helped a few points, but not much. They set their crush with traditional AG set-ups in mind to avoid stuck sparges and will never be a good crush for a BIAB set-up IMO.

 

How will mashout help efficiency? Doesn't that STOP conversion?

 

i find that the deathbrewer ...... ( http://www.homebrewtalk.com/f39/easy-stovetop-all-grain-brewing-pics-90132/ ) ... method on here is better than buying more grain and going no sparge ..

I have the grain double crusched and I mash thin for an hour ... then into another pot of about 185 degree water for ten minutes .. and bam !! ... I'm getting 78% to 88% efficiency eveytime now ... the thin mash is really important I have found .. last brew I used 3.75 galllons of water for 7.5 lbs of grain .. or 1.5 qts. per pound .. got 86% on that one.

 

no .. it helps the already converted sugars get off the grain .. i think ... I'm new, but I know I read that somewhere ... but like I said in my other post ... a little sparge goes a long way too ..

I personally am afraid of adding heat to my pot as I usually have it so full that the bag sits on the bottom ... so I don't mash out ... if I had more room, on a smaller beer maybe, I'd add som boiling water to get to mash out temps tho, I guess .. but I think I'd still sparge .. either way it's 10 more minutes tops .. good luck.

 

Squeeze the bag!

 

Don't have a picture of it, didn't take it before I started, but I did stir the heck out of the mash right when I mashed in. Stirred it until the temp dropped to 152 then covered and didn't stir again until heating for Mash out at 170.

I have thought about number 1, but I was unaware 90 minute mash was better than 60, I was just following the recipe, although I did change it around by adding the extra # of 2-row.

 

Actually the mashout temps just get the grainbed and wort more fluid for easier sparging(avoiding a stuck sparge) and is stops the enzymes from converting more starches to sugar...

I just don't see the BIAB process as needing a mashout intended for a traditional brew process...except for preserving your sugar profile by stopping conversion.

 

If you were able to "further" crush the grain with a rolling pin, I strongly suggest your grain was not all that well crushed.

http://www.homebrewtalk.com/wiki/index.php/Image:Crush_dry_tight.jpg

 

Well, the mash is all about converting starches to sugars...leaving it go a little longer will allow more of those starches to be converted.

I did a mash out on my first BIAB attempt and haven't done one since...but I'm not too concerned with "preserving my sugar profile."

 

first.. you ended up above your target OG.. that's a good thing. second. how are you measuring your volumes? if you want to calculate efficiency either pre-boil or post boil you HAVE to know the exact volume. being off by .25 gallons is enough to make you think you got horrible efficiency...

 

Mashout helps BIAB brewers because it allows the wort to drain from the grains much easier once the bag is lifted from the kettle. As you mentioned, it makes the grain bed more fluid.

The purpose of a mashout when BIAB brewing is to get as much wort from the grains as possible. It's not intended to stop the conversion or preserve any sugar profile.

 

Right now I just have a wooden rod that I have gallon markets on. The bad part with this is that my pot is so wide the gallon marks aren't that far apart so I am rough guessing when making the volume count.

I did go over the recipe target og, but like I said I attributed that to the extra 2-row I added. That brings a question to mind, which is more important, eff or the og? You can still get a higher og even if your eff wasn't that good, but aren't you missing fermentable sugars if your eff isn't that good?

 

I guess my process for BIAB is what wouldn't benefit much from a mashout not BIAB in general...I mash in 1.68 quarts/lb of grain and it drains plenty well...following that up with an 11 qt sparge in a separate kettle helps to further rinse the grainbed for me. If a person wasn't doing a sparge and was only mashing with 1.25-1.5qts/lb then I suppose I could see the worth in a mashout. Personally though, I can't imagine doing BIAB without a sparge of some kind...the amount of sugars I'm getting out of that 11qts of sparge water is way too much to leave behind. Since I don't mashout I still have some coversion happening in the sparge as well as a final rinse of the grain.

It works for me...but everyone will eventually tweak their process to one that works for them. That's what makes this hobby so interesting...there really isn't a right or wrong answer to many of these procedural questions. So, to the OP...I suppose just as most of us have, you'll have to try some new procedures until you settle into a comfortable process that can produce somewhat repeatable and predictable results.

 

+1 :rockin:

 

Tried a 90 minute BIAB mash, absolutely zero difference. I did it just because I was curious. Highly modified malts convert rapidly and if they are not converted in 60 minutes then something is wrong with your water chemistry, temperature or you didn't stir enough to prevent dough balls and of course the oft mentioned poor crush.

 

Now that's interesting...I'll have to shorten my mash time on the next brew and compare. Saving a half hour on brew day is a good thing if it isn't needed.

 

Well there is efficiency pre-boil and efficiency post boil... However for both you need to know exact volumes. If you get close to the OG then why worry.

 

I guess ultimately I eventually want to stop having to add an extra # of base malt for having no sparge. So im trying to get my % of preboil up so I know that my process is working and start to run with just the recipe.

If I didn't add the extra base malt do you think my OG would have suffered because of it?

What im trying to get at is seeing recipes on here that I would like to make and seeing their eff as 75%, but if I were to do it, if I don't have my procedures down good enough I would be looking at getting say 65% instead of the 75% that they are getting.

Personally what I think it is is a combination of a crappy thermometer and a sort of correct volume gauge, just what I am thinking.