Recirculating eBIABers -- to insulate or not

[ebstauffer]

I'm about four batches into dialing in my small BIAB system. First one I got (both from ColoBrewSys) was 160 quarts -- a bit large for 5 gallon batches. Bought a smaller 80 quart kettle with 5500 watt element. I just did my fourth batch of EdWortsHausPale -- not necessarily because I like it so much (although I do) but that it's relatively inexpensive and I know what it's supposed to taste like. But I digress.

My kettle is insulated with a double layer of reflectix. Cleaning it is a bit of a PITA as I have to unsecure it, roll it out, spray, rinse, repeat.

As it is my element rarely comes on during the mash. Do I care if it comes on a bit more frequently? Does the insulation help with mash temp homogeneity? What do recirc-ebiabers do?

 

[trav77]

I have a 15 gallon kettle although I typically do 5 gal batches. 5500 W ripple element in below a false bottom and a bag. I recirculate back through a fitting in the lid and a locline sparge ring that sits just below the surface of the mash.

No insulation... the element fires fairly regularly but the temp never fluctuates more than 1 degree F.

 

[doug293cz]

I'm about four batches into dialing in my small BIAB system. First one I got (both from ColoBrewSys) was 160 quarts -- a bit large for 5 gallon batches. Bought a smaller 80 quart kettle with 5500 watt element. I just did my fourth batch of EdWortsHausPale -- not necessarily because I like it so much (although I do) but that it's relatively inexpensive and I know what it's supposed to taste like. But I digress.

My kettle is insulated with a double layer of reflectix. Cleaning it is a bit of a PITA as I have to unsecure it, roll it out, spray, rinse, repeat.

As it is my element rarely comes on during the mash. Do I care if it comes on a bit more frequently? Does the insulation help with mash temp homogeneity? What do recirc-ebiabers do?

Yes it does. The faster you lose heat from the vessel, the higher the thermal gradients in the liquid, unless you have sufficient mixing from the recirculation to eliminate the gradients. If you have a long probe thermometer (like this one), you can take temperatures at different locations in the mash to get an idea of how big your temp deltas are with and without insulation. Temps should be lower near the walls of the vessel, and higher near the center. You may see top to bottom differences as well.

Brew on

 

[TexasWine]

I don't insulate and I measure temps in various spots almost every batch. I never see more than one degree of difference between the temp of the fluid being recirculated and the probe thermometer I use to poke around.

But, what Doug mentioned is 100% accurate. Maybe it's the sweltering Texas heat that gives me a lower gradient

 

[doug293cz]

I don't insulate and I measure temps in various spots almost every batch. I never see more than one degree of difference between the temp of the fluid being recirculated and the probe thermometer I use to poke around.

But, what Doug mentioned is 100% accurate. Maybe it's the sweltering Texas heat that gives me a lower gradient

Good data point. With some level of recirc during mash, gradients are insignificant. What is your recirc flow rate, what MLT construction, and what batch size? This info will make the earlier info you provided even more useful.

Edit: My post was just based on general thermodynamics. Actually having data from a real system that tells you where you actually are within the realm of possibility is priceless.

Brew on

 

[wilserbrewer]

Not a recirculator, but with sufficient insulation I don't feel the need.

Point being, the less insulation the more refined and well working your recirculating needs to be.....without insulation your recirculating game needs to be at the top.

While TW does not need to insulate, I believe he has invested in his recirculating process.

Nothing free lol

 

[TexasWine]

Good data point. With some level of recirc during mash, gradients are insignificant. What is your recirc flow rate, what MLT construction, and what batch size? This info will make the earlier info you provided even more useful.

Edit: My post was just based on general thermodynamics. Actually having data from a real system that tells you where you actually are within the realm of possibility is priceless.

Brew on

Ah yes, good call as everyone's system will behave differently.

Unfortunately for this thread, I've never measured my flow during recirculation. I simply flow as much as I can without sucking the level down below the false bottom, keeping an eye on the sight glass and ramping up the flow over the course of about 10 minutes or so. The throttling valve is never opened more than about 50%, but with a ball valve being equal percentage I'd say the % cv is maybe around 30%. If it helps, I have a MK-II pump, about 5 feet of silicon hose, an elbow for a dip tube, a branch tee at the return.

MLT is a 60 quart Bayou Classic. Sits on an old converted baker's rack type of shelving unit

Batch size is 6 gallons to the fermenter. When mashing, my total volume is usually between 9 and 11 gallons, depending on the grain bill.

BTW, heat transfer was one of my favorite courses. I'm always happy when someone applies the theoretical to this hobby.

 

[TexasWine]

While TW does not need to insulate, I believe he has invested in his recirculating process.

Nothing free lol

That would be 100% accurate. Took me some trials, and several errors, to nail down some best practices.

 

[ebstauffer]

Suppose I'll need to suck it up and clean my reflectix. I have a double wrap of it and a double thick "pad" my kettle sits on. The CBS kettle is a bit janky in that you can't put a lid on during the mash. As for recirc "rate", I keep mine quite low. What's the impetus for more flow? FWIW, using a Chugger pump. Hmm, how would I go about making a miniature mash-rake system...

 

[TexasWine]

The CBS kettle is a bit janky in that you can't put a lid on during the mash. As for recirc "rate", I keep mine quite low. What's the impetus for more flow?

I use a stainless steel cake pan as a mash cap. Floats on top. Bulkhead with a LOCLine manifold underneath evenly distributes the circulating wort. No need for a lid with this set up.

Higher flow ensures more homogeneity in the temp. But you have to balance this with the potential for grain bed collapse. That's one of the reasons I keep an eye on the sight glass.

 

[OdeCloner]

No way! Recirculation (roughly 50% on the ball valve) holds me dead steady on my 5500W eBIAB even in an unheated garage through a MN winter. I've measured the mash with a Thermapen in lots of different spots and found it all to be dead on. 50% recirculation on a Chugger/March is a huge amount of mixing, which works to keep the temps stable. Don't take my word for it -- try it.

Simplify, simplify. Drop that insulation and enjoy the cleaning time back. Let your eBIAB do its job.

 

[Homercidal]

I had not planned on using insulation with my BIAB Electric Recirculation setup (When I get to that point.)

I think with the temperature drop I've seen the heater would only come on a couple of times during the mash. NBD IMO.

 

[Horseflesh]

In my system (20 gal Colorado) the problem is that I can't circulate fast enough. The mash is just too thick. I measure a 5F swing between max/min temps in the grain bed.

To get the mash turning over as I'd like, I'd need to add a lot of extra water and increase my boil time.

 

[doug293cz]

In my system (20 gal Colorado) the problem is that I can't circulate fast enough. The mash is just too thick. I measure a 5F swing between max/min temps in the grain bed.

To get the mash turning over as I'd like, I'd need to add a lot of extra water and increase my boil time.

How about some information on internal configuration, batch and grain bill sizes? Maybe we can offer some help, but at a minimum it would be a heads up for others on what combinations they should watch out for.

Brew on

 

[ebstauffer]

I use a stainless steel cake pan as a mash cap. Floats on top.

Fantastic idea. Off to amazon...

 

[ebstauffer]

No way! Recirculation (roughly 50% on the ball valve) holds me dead steady on my 5500W eBIAB even in an unheated garage through a MN winter. its job.

What's your return look like? Mine is a length of silicone tubing held in (relative) place with a length of 10 gauge copper wire wrapped around. Respect the ghetto!

 

[ebstauffer]

In my system (20 gal Colorado) the problem is that I can't circulate fast enough. The mash is just too thick. I measure a 5F swing between max/min temps in the grain bed.

To get the mash turning over as I'd like, I'd need to add a lot of extra water and increase my boil time.

That's the exact system I have. Mine came with a solid-side basket. My boil-off rate with the insulation is just shy of 2 gallons / minute. This is with a 5500 watt element running at 80% . My "dial in" brew has an OG of 1050 which is manageable. Much more grain and I could be in trouble.

 

[Horseflesh]

I should have said, in my CBS 20 gal system I am only making 5 gal batches for now, which is probably a factor. I'll post some numbers later.

 

[OdeCloner]

What's your return look like? Mine is a length of silicone tubing held in (relative) place with a length of 10 gauge copper wire wrapped around. Respect the ghetto!

Yep, same idea here too. I've got a piece of silicone tubing that just goes back into the bag. I cut it long enough so that it curls around the kettle and creates a bit of a whirlpool effect. Same exact return setup that the Electric Brewery guys are using in their HERMS. Sabco too, actually.

With a full volume mash and my "The Brew Bag" bag, I can run my pump wide open without issue. (I don't, but it can be done.)

 

[Horseflesh]

Here are a few numbers for my E-BIAB system. It is the Nano Home 20 gal, but I am doing 5 gal batches. My system has the solid-sided basket. In Beersmith, I am using Full Volume Mash, and in the advanced prefs the "BIAB Grain Absorb" is set to 0.496 fl oz/oz. (The default is .586).

I changed the value to match what I saw after my first couple of batches. The default value gave me too much volume. The value may need tweaking. It may also be sensitive to the grain bill. For example, I recently did an oatmeal stout and forgot to do a beta-glucan rest as the manufacturer advises when you use oats -- the grain held on to a LOT more water and I had to top up after the mash.

I used to boil at 65% but reduced to 55% on advice from the manufacturer. (5 gallon batches, remember). My boil-off rate is ~1.33/hr and I target ~7.3 gal pre-boil, 6.25 post-boil, and 5.75 gal into the fermenter. Brewhouse efficiency is 65-70% with a couple of batches being a few points over 70%.

Anyway, some batch numbers are below. I'm still screwing around almost every batch so I don't know how helpful this is. My next batch will also use a wort return manifold.

Oatmeal stout (with beta-glucan rest and double-milled grain)
12.2 lb grain, 8.11 gal water, 79% mash efficiency. This mash was pretty loose and I got good efficiency. I still could not open the pump up more than half-way.

Hefeweizen (single-milled I think, and somehow I messed up a BeerSmith setting and used too much mash water!)
9.88 lb grain, 8.48 gal water, 93.8% mash efficiency. Because I used too much water the mash was very fluid and I was able to open the pump way up. This made a HUGE difference in efficiency, but I had to boil off the extra water.

Spotted Cow clone (single-milled I think)
13 lb grain, 8.16 gal water, 76% mash efficiency. I still could not open the pump up more than half-way.

My next batch, to be brewed Sunday:

Brown ale (single-milled and including the latest BeerSmith tweaks to batch size, kettle loss, boil-off rate)
11.01 lb grain, 8.28 gal water

 

[lawrenjl]

Here are a few numbers for my E-BIAB system. It is the Nano Home 20 gal, but I am doing 5 gal batches. My system has the solid-sided basket. In Beersmith, I am using Full Volume Mash, and in the advanced prefs the "BIAB Grain Absorb" is set to 0.496 fl oz/oz. (The default is .586).

I changed the value to match what I saw after my first couple of batches. The default value gave me too much volume. The value may need tweaking. It may also be sensitive to the grain bill. For example, I recently did an oatmeal stout and forgot to do a beta-glucan rest as the manufacturer advises when you use oats -- the grain held on to a LOT more water and I had to top up after the mash.

I used to boil at 65% but reduced to 55% on advice from the manufacturer. (5 gallon batches, remember). My boil-off rate is ~1.33/hr and I target ~7.3 gal pre-boil, 6.25 post-boil, and 5.75 gal into the fermenter. Brewhouse efficiency is 65-70% with a couple of batches being a few points over 70%.

Anyway, some batch numbers are below. I'm still screwing around almost every batch so I don't know how helpful this is. My next batch will also use a wort return manifold.

Oatmeal stout (with beta-glucan rest and double-milled grain)
12.2 lb grain, 8.11 gal water, 79% mash efficiency. This mash was pretty loose and I got good efficiency. I still could not open the pump up more than half-way.

Hefeweizen (single-milled I think, and somehow I messed up a BeerSmith setting and used too much mash water!)
9.88 lb grain, 8.48 gal water, 93.8% mash efficiency. Because I used too much water the mash was very fluid and I was able to open the pump way up. This made a HUGE difference in efficiency, but I had to boil off the extra water.

Spotted Cow clone (single-milled I think)
13 lb grain, 8.16 gal water, 76% mash efficiency. I still could not open the pump up more than half-way.

My next batch, to be brewed Sunday:

Brown ale (single-milled and including the latest BeerSmith tweaks to batch size, kettle loss, boil-off rate)
11.01 lb grain, 8.28 gal water

Sorry for the late response, but I have almost the exact system as you. I found that opening the grain mill to .045 allowed for full speed recirculation from the chugger pump and eliminated most the trub issues also. The pump running at full speed eliminated the temperature issues and increased my efficiency to around 85% into the fermenter. This is brewing 5 gallon batched and using the solid wall basket.

-Joe

 

[Horseflesh]

You mean you had been crushing finer than .045, but things improved when you went back to .045? I think .045 is CBS's recommendation, and my LHBS says their mill is set to .045... but I have no way to verify it.

How much water do you use? My mash is always thick enough that I can run my pump at half speed, at best.

 

[lawrenjl]

I do a full volume....for beer Smith, I use the biab profile, but changed the grain absorbation to the standard amount. I have been hitting all my numbers and average almost no trub