MLT with bag, finer crush for efficiency gain?

[grrickar]

So I have been reading a lot on BIAB lately, but I already have all my coolers setup for HLT/MLTs. My MLT is a 10 gallon Igloo sideline cooler with a false bottom and ball valve.

I have yet to use my setup yet (only extract brews prior to this), and I am curious to know if I could line the MLT with a bag and get away with a finer crush for a higher efficiency, with less risk of a stuck sparge (plus a bit easier cleanup I suppose).

I have watched a lot of vids and read a lot of articles about the methods I intend to use, and persons only getting 70-75% efficiency (batch sparging). I read more about some of the BIAB advocates getting much better than that. Is this due to grain crush size (finer for BIAB versus conventional manfold/false bottom)?

For those of you who have done both methods, do you find you efficiencies less, more or the same when doing BIAB?

So am I correct in that BIAB is favored for these reasons:

Finer crush = better efficiency + no stuck sparges

Less equipment needed

Easier cleanup = shorter brew day

 

[soccerdad]

So am I correct in that BIAB is favored for these reasons:

Finer crush = better efficiency + no stuck sparges

Less equipment needed

Easier cleanup = shorter brew day

I think there is data to support #'s 2 and 3 .. less equip for sure which means fewer items to clean. #1a will be debated for the next 100 years. There are biab advocates who say that their own data (experience) shows that a finer crush means either faster or fuller conversion .. and prob an equal number who say that their data (experience) shows that a finer crush is not necessary. I crush finer than most of my 3V brethren but not as fine as some folks who write about their experience. I am typically above 75% and below 85% with the mash, but I keep some of the fines out of the fermenter, so my efficiency into the fermenter may be less. #1b is always true .. no stuck sparge w biab

 

[doug293cz]

I don't think putting a bag in a traditional MLT will by itself prevent stuck sparges. BIAB doesn't experience stuck sparges because the bag is removed from the pot after mashing for draining wort, and the grain bed is never really "set." There is a lot more surface area for wort to escape from the sides of the bag, and not just the bottom, as with a traditional MLT. This reduces the average distance wort must travel to get out of the grain. Also, a hanging bag will provide some squeezing force to itself to help force wort out of the bag. And, you can manually squeeze the bag as much as you want/can to remove even more wort (although time and gravity may get almost as much.)

Brew on

 

[TexasWine]

As soccerdad mentioned, the crush debate will rage for centuries I'm sure. My personal experience is that I saw a significant jump in efficiency, between 5 and 10%, when I started crushing finer.

Also, I started shortening my mash times as well (30 minutes) at the same time I started crushing finer. Didn't think to try the shorter mash with the coarser grind, so I can't attest to if it works with it. But I can't help but think the finer crush is what allows me to do a 30 minute mash.

 

[soccerdad]

I apologize, grrickar, if I misconstrued your op. I had assumed that you were going to use a bag in your cooler to mash and them pull the bag. You would indeed have no stuck sparge doing that, and if was full volume (ala BIAB), your sparge would be passive anyway. But you *could* get stuck, as doug293cz noted, with your runnings coming through the bag and grain bed together. Am I making sense with that?

 

[Foosier]

I hit 85% today using a full volume BIAB and a good double crush.

In my opinion, a bag lined MLT should work fine. set the bag in the tun, fill with water and grain, stir and let sit. Then you can drain the first runnings and add your sparge water. Stir and let site again then drain. If it does not drain and becomes "stuck" just lift the bag a voila, everything will drain again. the bag is the best manifold ever.

That being said, unless you are dead set on using a MLT, you could just do BIAB. all you need is a 10gal pot and a bag to fit and you are ready to start. Then you can use the coolers to keep beers cold as the lord intended. ;-)

 

[Magnus314]

Yes, you can use a BIAB bag in your cooler. I do this often, and yes, it will help if you intend to grind finer in the pursuit of higher efficiency.

If you get a super slow run off, all you have to do is pull the bag up a little to break the vaccuum where the bag is stuck to the inside of the ball valve and it will flow faster again.

With a "coarse" LHBS grind, I get the same efficiency with mash tun or BIAB.

With a finer crush I get higher efficiency from both, with BIAB able to handle an even finer crush with no stuck mash, and getting higher efficiencies and faster conversion because of that.

To be clear though, fly spargers often mention very high efficiencies as well. They do it by very thoroughly rinsing the grain, and often run-off for an extra hour or more... and that longer grain-to-water contact time is - I think - a big part of why they get that high efficiency.

It seems like the higher BIAB efficiency is ultimately for the same reasons, but with a no-stuck-mash bag and a fine grind, we can get the same results in much less time. With a 30 minute mash my efficiency runs around 88% very consistently.

I've done overnight mashes with a course grind in my cooler mash tun and gotten nearly 100% efficiency. But the final beer had something like 94% attenuation and was very dry.

When I went for it with BIAB and ground the grain fine and did a 60 minute mash, the result was the same - high efficiency and very dry beer - but in 1 hour instead of 10-12 hours.

Since then I've gone with 25-30 minute mashes and has great efficiency AND proper attenuation with BIAB.

So if you BIAB, even in a cooler tun, and grind fine, you'll have to do a couple of tests to see how long you should mash, whether you want to sparge or not, etc.

I agree with the other benefits you listed, too.

 

[blizz81]

My own data, we've been doing a .028" crush for a while and been seeing right around 80% brewhouse efficiency. We recirc and have been using rice hulls, and have had some issues with the recirc sticking and struggling in a few brews.

Just did our first brew with a keggle BIAB added into the mix. It was a smaller brew than we normally do, but had 2lbs of wheat and the C40 I got was kind of end-of-the-bag shake-y...and no flow issues. We usually filter the runnings because even with the recirc, the very first bit to drain out is usually a bit grainey - no need to do that anymore. The false bottom was almost clean - not 100%, but definitely easier to clean that & easier to dump the grains.