First Traditional Mash for BIAB Brewer - A saga with questions

[Brewitt]

Yesterday I did my first traditional mash after several years of BIAB brewing. After brewing several hundred gallons using BIAB in a keggle, I got a great deal on a Blichmann Top Tier with three burners and three 26 gallon kettles with thermowells sight tubes and spigots. I brewed with a friend who wanted to do a Pliny the Elder clone so I cobbled together a recipe from several around the net intending to produce 13 gallons of wort at 1.070 from about 35 lbs of grain at 70% efficiency. I put together the recipe in BeerAlchemy which, after considering dead space in kettles and grain absorption and a 90 min boil suggested 17.25 gallons of pre boil wort at 1.052 prior to addition of 3.75 lb dextrose. After reading several articles I decided to go with 10.75 gallons of mash water and two sparges of 5.3 gallons each. Subsequent reading has made me question this decision but so be it.
So, the mash went relatively smoothly except for my missed strike temperature (148 instead of 151). However, with heat I corrected that and despite having to provide some heat here and there all was well. It does prompt me to develop a method to insulate my mash tun as the sleeping bag I used for my keggle didn't fit on my pot.
My first surprise came when, after mashing out, my runoff yielded only 4.25 gallons wort (I expected about 7). I then went ahead and sparged twice with 4.3 gallons (forgot 5.3 was the amount needed) of 171 water (I think I needed a higher temp since it cooled upon hitting the cooler mash but I'm not sure how to determine the proper temp). After those two sparges I collected a total 13 gallons of wort rather than my target of 17.25. Of course, I missed two of the gallons but that left more than two gallons in the grain (was my initial expectation incorrect?). In my haste to correct that, I added two more gallons of sparge water to bring my total runoff to 17 gallons (was a third sparge a problem?). The good news is, aside from the volume issue, my first lautering process went very smoothly.
Now came the biggest surprise. I checked the wort with my refractometer, which has been quite reliable, and came up with 17.8% brix or 1.070 SG. This was my anticipated post boil gravity after adding 3.75 lb sugar. I was very confused, expecting to miss my numbers in the other direction. Not only that, but this represented an efficiency approaching 100%, clearly not possible. So at this point we decided to get closer to the target gravity and create more wort (since my boiling pot allowed it) and I diluted the wort to 20 gallons prior to starting the boil. What had happened here? My only rational conclusion is that when my friend bought and ground the grain at our LHBS, the fellow that helped her inadvertently, or by an error of my friends, gave us way too much grain. It didn't look that far off based on how full the bag was but, who knows. Any other guesses?
From here on out, the process went smoothly. We ended up with 17 gallons of 1.074 wort which we split between carboys after chilling with my new (and I mean delivered by FEDEX while were were boiling) Counter Flow Chiller and pitched with WLP001 or Safale 05 (too much wort for my WLP001 Starter). It is happily bubbling away.
I am thrilled with the new setup, far more than I imagined having but I couldn't pass it up. I loved BIAB and I think I'm going to love this once I get used to the process and refine my technique and setup. I appreciate any input or solution to my mystery. Until then I think I'll RDWHAHB.

 

[acidrain]

Grain absorption is .12 gal. per lb., so you can figure on 4.2 gal. absorbed into the grain.
Also, mashing at a little under 1.5 qrt/lb means you should have started with 13 gallons of strike water. Less the absorbed water in the grains will yield 8.8 gal.

 

[J187]

Post your recipe.

 

[Brewitt]

Post your recipe.

Here is what we used with the volumes and SGs mentioned above. (by the way, I confirmed the SG derived from the refractometer by hydrometer and they were within a couple points):

US 2-Row Malt 32lb 8oz 84.3 % In Mash/Steeped
Belgian CaraPilsner Malt 1lb 4oz 3.2 % In Mash/Steeped
US Caramel 40L Malt 10.00 oz 1.6 % In Mash/Steeped
German Sauer(Acid) Malt 7.00 oz 1.1 % In Mash/Steeped
Sugar - Corn Sugar/Dextrose (Dry) 3lb 12oz 9.7 % End Of Boil


Hops
Variety Alpha Amount IBU Form When
US Columbus(Tomahawk) 15.5 % 4.00 oz 90 Min From End
US Warrior 15.5 % 1.00 oz 90 Min From End
US Simcoe 13.0 % 2.00 oz 15 Min From End
US Columbus(Tomahawk) 15.5 % 1.00 oz 15 Min From End
US Centennial 8.5 % 3.75 oz At Shut Off
US Simcoe 13.0 % 2.00 oz At Shut Off
US Centennial 8.5 % 3.25 oz Dry-Hopped
US Simcoe 13.0 % 3.25 oz Dry-Hopped


Other Ingredients
Ingredient Amount When
Yeast Nutrient In Boil
Irish Moss In Boil
Clarity-Ferm In Fermenter

 

[J187]

For one... plugging into beersmith I get 1.070 as an OG BEFORE your sugar addition. As for the volumes... Also, I calculate that 3.75lbs of dextrose would only give you an additional 12 points.. so If you thought you were supposed to be 1.070 after adding the sugar, I would think you'd expect to be at 1.058 before hand.

How are you measuring the volumes? Unless you had a LOT more grain absorption, you are still missing some gallons...

10.75 - 4.2 = 6.55 - dead space .25 = 6.3 first runnings. Since you seem to have hit the 1.070 that I calculated your expected gravity to be, could you have simply miscalculated the vol collected after the mash/lauter?

 

[Brewitt]

For one... plugging into beersmith I get 1.070 as an OG BEFORE your sugar addition. As for the volumes... Also, I calculate that 3.75lbs of dextrose would only give you an additional 12 points.. so If you thought you were supposed to be 1.070 after adding the sugar, I would think you'd expect to be at 1.058 before hand.

Was the 1.070 you calculated for my grain amount in the intended pre boil volume of 17.25 gallons or was it for the 13 gallons of runoff I actually ended up with ? I came up with an additional 10 points from the sugar but are you forgetting the boil off from a 90 min boil? I think 18 points is reasonable if not a little under. I did the same recipe through an online calculator and came up with comparable numbers (1.052 for pre boil and 1.070 for OG).

How are you measuring the volumes? Unless you had a LOT more grain absorption, you are still missing some gallons... 10.75 - 4.2 = 6.55 - dead space .25 = 6.3 first runnings.

Correct, by my calculation I am still missing over two gallons of wort. I originally expected around 8 gallons of first runnings but I forgot that I wouldn't be squeezing the grain. Although with BIAB I squeeze the bag a bit after sparking, my understanding is that is not traditionally done with this type of mashing. The grain was quite wet at the end and there was a little pooling at the bottom when I scooped out the grain but probably a couple liters, not a couple gallons.

Since you seem to have hit the 1.070 that I calculated your expected gravity to be, could you have simply miscalculated the vol collected after the mash/lauter?

It is true that my calibrations on the sight tubes was from the prior owner and has not been verified. It is also true that I don't really know all the volumes of the dead spaces in the system. However, based upon the amount I got out post boil and the amount that was left in the pot after transfer, I think my post volume was off by, at most, a gallon. So even if I had 16 gallons post boil, rather than 17, my gravity is unexpectedly high and my calculated efficiency unrealistic (around 85%) or maybe that is not as unrealistic as I think it is. What do you think?

 

[acidrain]

I am still missing the boil off rate... you can't end up with 17 gal from a 17.25 gal pre-boil.
Also, did you stir the wort prior to taking measurements? Mash and sparge collections will stratify and give false readings.
You started with 17 gal. How much made it into the fermenter?

 

[Brewitt]

I am still missing the boil off rate... you can't end up with 17 gal from a 17.25 gal pre-boil.

Sorry, its a confusing saga. Intended pre boil was 17.25 gal. Added extra water due to the high SG and ended up with about a 20 gal pre boil. Calculated boil off at about 2.7 gallons in 90 minutes. I may have lost 3 gallons since I boiled pretty vigorously.

Also, did you stir the wort prior to taking measurements? Mash and sparge collections will stratify and give false readings.

That is a good question. I can't be certain. My final gravities were definitely correct but I could have had some variability in the early ones. They are not completely consistent with the final but not too far off.

You started with 17 gal. How much made it into the fermenter?

As I said above, I started with 20 and ended with 17.

Hope that helps clarify things.

 

[J187]

Stupid question... Did you mash in the kettle with the sightglass and read the volume on the sightglass with the grain in there and forget to account for displacement of the grain?

 

[J187]

Calibrate the sightglass. It would take 10 min and is worth knowing. Your preboil should have been around 1.055. For what it's worth... Beersmith days you should have had 1.082 for an OG when I plugged in all grain plus the sugar at a 13 gallon batch vol with a 17gall preboil at 70% ef

 

[Brewitt]

Stupid question... Did you mash in the kettle with the sightglass and read the volume on the sightglass with the grain in there and forget to account for displacement of the grain?

Since it was my first time mashing in a mash tun, no question is stupid. But, no, my MLT does not have a sight glass. Just the HLT and BK.

 

[Brewitt]

Calibrate the sightglass. It would take 10 min and is worth knowing. Your preboil should have been around 1.055. For what it's worth... Beersmith days you should have had 1.082 for an OG when I plugged in all grain plus the sugar at a 13 gallon batch vol with a 17gall preboil at 70% ef

I will definitely check all the volumes on my sight glasses before my next brew day. 1.055 is close to my calculation of 1.052 (without sugar) but it was 1.070 instead. Since I diluted further, to 20 gal, and boiled back to 17 gal, I didn't do the other calculations or measurements.

 

[J187]

Its one of those things where it almost has to be some kind of fairly large volume error... I mean, as you already mentioned, you didn't get 98% efficiency - something has to be wrong. Did you measure and crush the grain? Given the high amount of grain in the batch could someone have miscalculated the grain quite a bit?

 

[Brewitt]

Did you measure and crush the grain? Given the high amount of grain in the batch could someone have miscalculated the grain quite a bit?

Your coming to the same conclusion I did. My friend picked up the grain. Unexpectedly the guy from the LHBS helped her weigh and grind the grain. Perhaps he made a 10 lb error in the 2-row. That might explain it. I actually mention that possibility at the end of the "saga". I didn't think it was that off but could it have been? Sure.


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[J187]

Don't forget... you could have gotten like 80% efficiency... so it wouldn't really have to be a huge mistake in grain... especially since if you did get a much higher, but reasonable, efficiency than you planned. If you got higher efficiency, it's a compound effect because the higher efficiency is on the larger amount of grain... I have had an experience where the LHBS undercut my grain bill and I had to add DME at the boil. Happens.

 

[Brewitt]

You make a good point. What is ironic to me is that I always weigh out my own grain and, this one time, someone else went and the LHBS guy did the weighing. This is especially coincidental because I was particularly focused on figuring out the characteristics of a new brewing system and a new mashing technique.


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[Brewitt]

Thanks every one for their comments. I'll keep my eyes open on this one.

I still have several questions:

Could I have gotten 85% efficiency?

What is the optimal water to grain ratio for mash?

Is it ok to batch sparge 2 or more times?

Obviously there is a range of opinion but is like to get a general consensus.



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[J187]

Thanks every one for their comments. I'll keep my eyes open on this one.

I still have several questions:

Could I have gotten 85% efficiency?

What is the optimal water to grain ratio for mash?

Is it ok to batch sparge 2 or more times?

Obviously there is a range of opinion but is like to get a general consensus.



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Yes, you could have. You'll hear people saying they got 95% or even 100%... they measured their volume wrong . But 85... that's doable. 80% is definitely something you'd see and that could have been what you hit with a little more grain.

Optimal range? Between 1.0 and 4.9 qts/lb. I say that in jest because it is not all that inaccurate and points out the fact that it's almost all personal preference. Now... there are obviously many things to consider at the extremes, but if you are in the 1.25-2.25 range, you are right where most are and within that range, it depends on your equipment and your desired effect and what you are comfortable with. I mash most beers with 1.5 qt/lb. It's easy to calculator, easy to remember, and it gives me a nice balance where I have enough water to hold temps - too thick of a mash might not hold temps really well as water does a much better job holding temp than grain. That also allows me enough water to sparge, whereas if I mashed with 3 qts/lb, I wouldn't have much room for sparge water. The reality is, you'll get a thousand answers, but I'm of the mind that it doesn't make a huge difference in terms of fermentability or anything else truly impactful to your brewing. Some folks - I think Mike McDole, stick with one set mash volume and allow their ratio to change appropriately. It's all preference.

Multiple sparges... so this is another area of debate and preference. It's very possible to get more extraction from a second or third batch sparge, but at what cost? The runnings there are thought to not be of the same high quality - there is a cascading effect where first runnings are the highest quality, and subsequent runnings are of lesser and lesser quality. Personally? I batch sparge once. I don't want much to do with the third runnings of the wort. How, if you have a small MLT or something, it's fine to do in my opinion. Some people like to do it for ease of use - smaller volumes to lift and pour, and others really want extra efficiency. To me, if I am getting my 72% efficiency with one batch sparge, I'm happy with that and the quality of wort I'm getting. What's more important in my opinion, is to find the process that gets you the SAME efficiency each time. Then you can dial in your recipes and repeat your process with ease, knowing what to expect!

 

[Brewitt]

I appreciate the thorough rundown on mash ratios. I have been, until now, a brew-in-a-bag guy. There the mash volumes are large and you get good beer. I usually did a couple small sparges of my grain bag. Now I have a 26 gallon 3 tier system so room is not an issue. I guess I will play with it.

I was with a bunch of experienced brewers last night and they imagined I just may have gotten 85% efficiency. If that is reproducible, I'll take it. ;-)


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[J187]

I appreciate the thorough rundown on mash ratios. I have been, until now, a brew-in-a-bag guy. There the mash volumes are large and you get good beer. I usually did a couple small sparges of my grain bag. Now I have a 26 gallon 3 tier system so room is not an issue. I guess I will play with it.

I was with a bunch of experienced brewers last night and they imagined I just may have gotten 85% efficiency. If that is reproducible, I'll take it. ;-)


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I did a BIAB batch for the experience. I liked it. I like traditional mashing much better though personally.

85% wouldn't get you there though... there would have had to be something else wrong too. You weren't kidding when you said it would have to be something approaching a congress mash. I bet you'll settle in around the 70s like most. I like that range, I know I get quality wort and I'm comfortable that I can reproduce it over and over.

 

[Brewitt]

I just got the valve and all the connectors for my pump setup from Brewer's Hardware. This allows me to adjust the height of the pots on my Blichmann Top Tier to make the geometry much more manageable. That required some replumbing of the gas lines, which is also done. My pump is supposed to come next week so I will just have to make the two connections and figure our the mounting (no brackets on the valve or the pump as far as I can tell).

I do have a question. My three way valve is actually four way (I can also have all three directions open). That means I can't use it to regulate flow rate. My pots have spigots but I understand that I can't restrict flow upstream, only downstream. Is that correct and, if so, is my only option to put another spigot downstream? Can I use a rheostat on the pump as an alternative?

 

[Brewitt]

Here's the configuration with the lowered MLT and HLT and my 3-way valve setup ready for the pump in place of the piece of pipe to the right. Bottom will feed CFC, left will be tube for MLT recirculating and for transfer to BK. Only connection I will have to change during brew is to swap the tri lover connector from MLT to BK outlet. I am still contemplating the mounting of the CFC and pump to the Top Tier system but I do know the valve will be above the pump. Comments welcome.


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[Brewitt]

Sorry, those were meant for another thread about pumps.


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