MIAB procedure questions

[Brockness Monster]

I will start by describing/listing my equipment and then get to the questions

8g BK w/ball valve
10g Igloo Cooler with ball valve and Bazooka screen
5g Igloo Cooler with ball valve (can't stop this thing from leaking, but its slow)
Wilser BIAB Bag brewhardware

On my last brew, which was my first in 7 years, I did a few things that are hold overs from my fly sparging days and a few new things that might be trivial or bad practice. So here are my questions:

1. How often should I stir the mash?
2. Do I need to Vorlauf to try to clarify wort?
3. Do I need to wait any length of time after adding my batch sparge water and stirring?

Now that the questions are out of the way, here is what i did on brew day regarding those questions

1. I stirred the mash every 15 minutes to ensure I was maximizing homogenization of the sugars.
2. For both the Mash and the batch sparge I poured 2 one-gallon pitchers full of wort and carefully added them back to the top of the mash before transferring to the BK. I also squeezed the mash bag after the sparge was transferred, completely negating the vorlauf. I am thinking there is no need for the vorlauf.
3. After adding the sparge water and stirring, I waited 5 minutes before vorlauf and transfer. I am thinking there is probably no need.

So far I am a fan of this MIAB process. If I can keep the mash efficiency above 80%, I don't see a point in going back to fly sparge.

 

[Agent]

1) I personally also like going with 15 minute intervals as well.

2) You are correct in that vorlauf is totally unnecessary if you are going to squeeze the bag.

3) Depends on how thorough you want to be at extracting everything you can. A quick stir and drain will simply rinse the grains, while extracting the extra sugars within the grain will take a little bit of time.

The brew bag is certainly wonderful.

IMO - Going to single vessel and no sparge has been the biggest benefit for speed, space, and time.

 

[Brockness Monster]

I will eventually go single vessel, got my eye on a spike kit on Bobby's site. Need to save some money and figure out the best upgrades first.

With regards to #3, do you have a recommended time?

 

[Willy]

1) i also use the ~ 15 min interval mash stir in the bag. My method is to "fluff" from the bottom and stir upwards. (Increase circ, keep O2 out).

2) vorlauf is optional I believe. (I would have to look it up. Bwahahaha)

3) I gave up squeezing with my hands. I now use a ratchet strap - wind it around the bag and crank it down. Like milking a cow but squeeze the whole thing, no utters to worry about.

All in one electric, BIAB and and no sparge makes a brew day quite easy and relaxing. Cleans up easier too.

 

[Brewer dad]

I usually stir at the 30 minute mark, and try to leave little to no liquid behind in my mash tun. That consistently nets me in the high 70’s for efficiency, which I am happy with. For whatever reason if I am a little short on volume I can do a dunk sparge(another bag benefit), but haven’t needed that for a while.

I am also in the process of upgrading to a system like Bobby’s. If you are budgeting I highly recommend checking the secondary market in your area. I’ve had some good look on things like Facebook marketplace.

 

[Broken Crow]

Everyone's answering the questions you asked and they likely know better than me, so I'll answer the question you didn't ask:

5g Igloo Cooler with ball valve (can't stop this thing from leaking, but its slow)

Statistically this is likely a bulkhead issue. Take a look here:
https://www.homebrewtalk.com/threads/do-i-need-food-grade-plumbers-tape.734414/#post-10417185
and maybe here: https://www.homebrewtalk.com/thread...system-for-cheap.680992/page-16#post-10364989
Getting bulkheads to seal properly is one of those things you can do a million times but until you see the problem with your own eyes, all our words are for naught.

 

[Brockness Monster]

Thanks for the links. I will look through them. I was also thinking about closing it off completely since I only use it to hold hot water for the sparge while I am draining the mash in the BK. Either way, something I need to fix so I appreciate it.

 

[doug293cz]

On my last brew, which was my first in 7 years, I did a few things that are hold overs from my fly sparging days and a few new things that might be trivial or bad practice. So here are my questions:

1. How often should I stir the mash?
2. Do I need to Vorlauf to try to clarify wort?
3. Do I need to wait any length of time after adding my batch sparge water and stirring?

Now that the questions are out of the way, here is what i did on brew day regarding those questions

1. Other than at dough-in and prior to lautering (wort draining) there is no real need to stir the mash during mashing. At dough-in, you need to make sure the grain and water are well mixed, and that there are no dough balls, as any dough balls will decrease your conversion efficiency. Prior to lautering, you want to stir (or vorlauf) in order to homogenize the wort, so that the wort retained by the grain is not higher SG than the drained wort. Stirring during the mash may help keep the temp more uniform throughout the mash, and may speed up conversion slightly by moving high SG wort away from the surface of the grits. Stirring will expose the wort to more oxygen, so if you are a LoDO brewer, you probably want to avoid excessive stirring.
2. Clear wort into the BK is mostly a personal preference item, but if you want clear wort to the BK, then vorlaufing, or recirculating during the mash, will promote that. If you want clear wort to the BK, do not squeeze the bag, as this will push flour thru the openings in the bag, and undo whatever vorlauf did for you.
3. What you want during a batch sparge is to homogenize the retained wort with the sparge water, so that what is retained after draining the sparge is no more concentrated than the drained wort. The time to homogenize depends on how long and aggressively you stir, or the dwell time (during which diffusion occurs) if you don't stir. With a reasonably aggressive stir for several minutes, there should be no need for a dwell time post stir.

But, however you approach these, you will get beer.

Brew on

 

[Brockness Monster]

Ok, after reading the threads that Broken Crow linked, I think I will be picking up a couple items from Bobby's site to fix the leak on my HLT, and reinforce the fittings on my MLT just in case. Just need to measure the size I need. As far as my questions are concerned, the following is what I will use on brew day.

1. I think I am going to continue to stir the mash every 15 minutes. I am not worried about LODO, and besides homogenizing the sugars throughout the system, keeping the temperatures uniform throughout the mash is an appealing idea.
2. No Vorlauf. I am not worried about wort clarity, and I have plans later on for a whirlpool system to keep hot break materials and hop matter out of my fermenters. Also, the idea of increasing efficiency, even a little bit, by squeezing is appealing to me.
3. I will continue to give the sparge 5 minutes of rest after mixing into the mash and then stir again before transfer. my brew kettle needs time to heat up anyways and this won't hurt anything.

Another idea I had was squeezing the initial mash to remove as much sugar as possible before the Sparge, and then squeezing again after the sparge. This should allow more of the leftover sugars in the grain to move into solution since the concentration will be lower. Might be able to eek out a couple more points of efficiency. I'll have to try it after I rig a pulley system for the Wilser bag.

 

[doug293cz]

Another idea I had was squeezing the initial mash to remove as much sugar as possible before the Sparge, and then squeezing again after the sparge. This should allow more of the leftover sugars in the grain to move into solution since the concentration will be lower. Might be able to eek out a couple more points of efficiency.

Yes, this is exactly what you want to do to maximize lauter efficiency when squeezing. If you only want to squeeze once, then squeezing prior to sparge is the best way to go.

Squeezing reduces the grain absorption rate, which increases lauter efficiency, as shown in the chart below (which assumes equal absorption rates for initial drain and sparge drain, so either no squeeze or a good hard squeeze for both.)

Brew on

 

[MaxStout]

In warmer months I do no-sparge BIAB over propane in the garage. I only stir at :20 and :40, the first stir mainly because I draw a sample for pH measurement then. Besides, in most cases conversion is complete after 20 or so minutes. I only lose a couple degrees in 60 minutes.

After the rest I hoist up the bag and squeeze while I start heating the kettle to a boil.

In cold months I brew 5 gallon batches indoors on the stove top with an 8 gal kettle. For all but the smallest beers I need to set aside some water to add post-mash. I used to pour that water over the grain bag but I was getting astringency issues, so I now just pour it straight in the kettle after I've removed the grain. No more astringency.

Squeeze the bag like it owes you money. You'll get another quart or so of wort and a little more efficiency. Every bit counts!

 

[Bobby_M]

1. How often should I stir the mash?

No need to. The enzymes will find the starch. The sugar will find equilibrium. Opening up the mash tun will lose heat and introduce oxygen every time. Both of those things are not improvements.

1. Do I need to Vorlauf to try to clarify wort?

If you're not going to squeeze the bag at all and you're looking for maximum wort clarity into the boil kettle, it certainly won't hurt to vorlauf about a gallon.

1. Do I need to wait any length of time after adding my batch sparge water and stirring?

No. Vorlauf, drain. Add sparge, stir, vorlauf, drain. I have enough evidence from some personal experimentation that a highly turbid preboil wort is slightly detrimental to beer flavor so I would recommend not squeezing. If you're falling short of your preboil volume requirement, work in a little more sparge water next time.

So far I am a fan of this MIAB process. If I can keep the mash efficiency above 80%, I don't see a point in going back to fly sparge.

I'm a fan of the BIAB process skipping over the dedicated mash tun. My saying is; I don't care what the efficiency is as long as I can hit the same one consistently. I will never go back to any kind of sparge, nevermind fly.

 

[Brockness Monster]

The lazy side of me definitely wants to take your advice on question 1, especially since Doug was hinting toward the same thing, so I will try it out on this brew.