2nd try BIAB

After a somewhat sloppy first attempt, I was able to make some changes for my second crack at BIAB. Many of the threads posted here really helped me out for my second try. I think that attempting an imperial IPA for my first brew was pretty foolish, so for my second attempt I brewed an American IPA with a 14.4lb grain bill in the hopes of getting 5.5G into my fermenter. Some the changes I made were to re-mill my grain with a ghetto pasta mill and use a wooden press to drain the bag. I may not be calculating my efficiencies correctly but I started with 8.75G of water, 90 min mashout recording sg of 1.052 (81F) preboil and then a 1.078 (65F) after a 90 min boil. If I calculated my efficiency correctly (using brewersfriend) I get 82% efficiency for the 5.5G of wort.

I think what really helped is the wooden bag press I built, which I was able to use to effectively squeeze out virtually every drop of wart. The other slick thing about the press is that it bears the entire weight of the bag just as soon as you hoist the bag above rim level of the kettle. So my pulley and eye hook only bear weight for a couple of seconds, and I can effectively drain the bag dry in five minutes. Having never posted an image I'm not sure if you can see the image of my press.
[IMG="https://imageshack.us/i/f02rjTAuj"]

Eamon said:

After a somewhat sloppy first attempt, I was able to make some changes for my second crack at BIAB. Many of the threads posted here really helped me out for my second try. I think that attempting an imperial IPA for my first brew was pretty foolish, so for my second attempt I brewed an American IPA with a 14.4lb grain bill in the hopes of getting 5.5G into my fermenter. Some the changes I made were to re-mill my grain with a ghetto pasta mill and use a wooden press to drain the bag. I may not be calculating my efficiencies correctly but I started with 8.75G of water, 90 min mashout recording sg of 1.052 (81F) preboil and then a 1.078 (65F) after a 90 min boil. If I calculated my efficiency correctly (using brewersfriend) I get 82% efficiency for the 5.5G of wort.

I think what really helped is the wooden bag press I built, which I was able to use to effectively squeeze out virtually every drop of wart. The other slick thing about the press is that it bears the entire weight of the bag just as soon as you hoist the bag above rim level of the kettle. So my pulley and eye hook only bear weight for a couple of seconds, and I can effectively drain the bag dry in five minutes. Having never posted an image I'm not sure if you can see the image of my press.
[IMG="https://imageshack.us/i/f02rjTAuj"]

Click to expand...

Nice bag press. Reminds me of a scaled up version of a device from the Spanish Inquisition.

Brew on

Love it when my hobbies come together - firing up the drill press tonight to make one of these for sure!

It is cool when you can use one hobby for another. It's suppose it's pretty obvious how it's put together, but it is simply two 2x10 boards cut to 19.5 inches (my pot diameter is 18") with 1"x17.5" dowels mounted into each of the two boards. I drilled 1" holes with a forstner bit 1" deep into each board at the same exact location to serve as rails to guide the two boards. The rails help make it a one hand operation to squeeze the bag as you hoist it through the press. You can pretty much squeeze as much wort as you wish, although I am a little concerned if you squeeze too much you could rip your bag. I now find the whole hoisting and squeezing of the bag to be pretty slick and efficient. Next time I use it I plan to weigh the bag before & after squeezing, and also measure the extra volume on my sight glass just to get a better idea what I'm accomplishing.

While I applaud your efforts, I think someone did a comparison of wort produced from a hard squeeze vs merely letting the bag hang and drain. If I recall, there is not much difference in volume, of course the squeeze is faster...

My apologies, don't like to be the Debbie downer buzzkiller.
Cheers...and whatever makes you happy works for me....

Cant see pic.

JONNYROTTEN said:

Cant see pic.

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Sorry you can't see the picture but I can't figure out how to properly post a picture. I must have an error in my syntax or perhaps I'm not allowed to post pictures. You can copy the http link to your browser window, but I know that is kind of a pain. I really should break down at some point and become a supporting member.

I'm trying another method to post the picture.

I know it has been suggested that squeezing the bag provides no additional volume compared to simply letting the bag drain. As a novice to BIAB I have little experience comparing squeezing to static drainage of the bag, other than it "seemed" like I had more volume on my second attempt when I used the press (and the squeezed bag seemed lighter). I do have some familiarity with flow processes in porous media. It's probably wrong of me to compare this process to an oil reservoir, but my experience there tells me that gravity drainage can be an especially inefficient process, since the surface area the porous media and the inter-facial tension of the fluid can conspire to lead to high fluid retention. A surprisingly high proportion of fluid can be retained in in fine grained material unless you add dynamic energy to the process (squeezing) or change the viscosity of the fluid (heating or dilution). It would not surprise me at all if the grain held back more than 50% of the wort volume, even if you left the bag to hang for hours; and time is not necessarily your friend here as the bag cools and fluids get more viscous. My perspective is to squeeze the bag while the wort inside it is hot and be done with the process in a few minutes. The cost of the material is less than $10. The other benefit that I see is that this process puts much less stress on my eyebolt/pulley since it only bears a fraction of the weight and only for a couple of seconds until I squeeze the press.

One thing I do plan to do on my next batch is to record the volume prior to hoisting the bag, weigh the bag upon exiting the wort, record the volume upon exiting the wort, squeeze the daylights out of the bag, then reweigh the bag and record the volume on the sightglass. In this way I can roughly calculate the wort volume gained both by volume and weight differences. This won't settle the argument regarding the efficiency of gravity drainage but I will at least know what's at stake.

Ok sounds good, when your done squeezing set the bag aside and you will likely find a small puddle of wort that has drained by gravity, just my experience.
Cheers and nice work.

This sounds like a great experiment for your system indeed - hang one and squeeze one and let us know your findings, either way I'm making one if for no other reason than stress relief... GIVE ME MY WORT DAMN GRAINS, I SQUEEZE YOU TO DEATH!

Ahem...

Time for bed!

wilserbrewer said:

While I applaud your efforts, I think someone did a comparison of wort produced from a hard squeeze vs merely letting the bag hang and drain. If I recall, there is not much difference in volume, of course the squeeze is faster...

My apologies, don't like to be the Debbie downer buzzkiller.
Cheers...and whatever makes you happy works for me....

Click to expand...

I, too, am the last person to want to be a wet blanket when it comes to making gadgets. After all, I've brewed 18 years and made a two tier three vessel direct fire recirculating system with a pump, sparge device and auto-sparge valve. When I started using BIAB, I squeezed the bag like it owed my money. Then Mike said he just let his drain with no squeezing, so I tried it. By the time my boil starts after lifting the bag and just letting out drain vs squeezing, I get no difference. So now I just let my hot bag hang and drip dry.