Biab Draining The Grain

[felten]

One question I have though, is how much should I be losing to trub? I stopped draining when the trub started going into the urn tap (I did whirlpool), but still ended up with 2.3 litres left.

Is this normal.

Thanks

Very normal, I think anything under 3L is doing pretty well. It's one of the cons of BIAB, but it makes up for it in other areas like less liquor lost to grains and no mashtun deadspace.

 

[kymba]

If you have a couple of spare shelves and a $8 Willow Washing Bowl then the BribiePressinator is an option as well:

:icon_cheers:

bribie can you just put the pressinator on top of the urn and do away with the bowl?

 

[Amber Fluid]

Thanks everyone for the replies. Some useful information I will take with me to the next brew day.

I found squeezing quite simple really. I have an electric hoist I put over the urn and that lifts and suspends the bag quite easy. I then slipped on some rubber kitchen gloves (new out of the packet) and squeezed until I could squeeze no more.

With regards to putting the wort into the cube for no chill, I see everyone able to squeeze the cube to expel the air in there. However, I filled the cube right to the very top so was not able to squeeze the cube to get the little bit of air out from the handle. Does this make any difference or should I have only filled the cube close to the top which would enable me to squeeze it without losing anything?

I managed to completely fill the cube to the top and filled a 1.5 liter V8 jar and I still had some left over. So I am now wondering how much volume is in a 20 liter cube? (It is a 20L FWK from Ross)

 

[Amber Fluid]

Hi Amber Fluid

Congrats on the first BIAB, wonder if you used the spreadsheet.

I squeeze the bag, had not thought of weighing it like Stux, but hit my volumes consistently.

I decide what I am going to brew, add the water to the urn, whilst it's heating to Strike Temperature, I weigh and add any water treatment, weigh and crush the grains, weigh the hops that way everything is ready.

I measure the water volume (using a steel rule) when filling the urn, start of boil, end of boil and only do an SG when transferring to the cube (refractometer), initially I also did an SG at start of boil but now no longer bother.

Yes mate, I used the spreadsheet. I had a rough idea of water volume etc to use as I had a good mentor (BribieG, thanks). But I still wanted to run it over the spreadsheet for figures etc. I also ran it through BrewMate which wasn't a great deal different. I admit though, I was a bit concerned of the hops and how bitter it was going to be so cut back a little from what the actual recipe suggested. I seem to like IBUs between 20-40 and I was looking at hitting 64.

 

[Spork]

Congrats Bill. It is easy isn't it. Sure, perfecting the method could take years, but close enough is what we can expect on the first few brews, and the results should be very tasty.
I don't think anyone answered your Q re: calculating efficiency yet, unless I missed it, so here goes:

I take it you are using BrewMate or similar? This defaults to 70% efficiency IIRC.
So, if you started with the amount of grain and water you told the software you would, and hit the SG (before boil) the software predicted, your efficiency = 70%. If you had a higher OG, your eff. is > %70. If lower, the eff. is < 70%. BrewMate also tells you post boil gravity and volume. If your results differ but pre boil were correct just change "evaporation rate" in the settings until you find the correct one.
It takes a few brews to "dial in" your numbers, and these can change to depending on other factors - crush being one, process another, and I believe making "bigger" beers - ie: more grain, less water, will reduce efficiency.

ps.
One of the best things I have done was to get a measuring jug and a marking pen and mark 2 and 10 litre graduations on the sight tube of my urn. Lets me keep tabs on volume after hoisting the bag, boiling, etc.

 

[stux]

I squeeze the bag, had not thought of weighing it like Stux, but hit my volumes consistently.

It's apparent absorption, which is basically the difference between strike volume and mashout volume (or start of boil) all corrected back to 65C

 

[Amber Fluid]

Congrats Bill. It is easy isn't it. Sure, perfecting the method could take years, but close enough is what we can expect on the first few brews, and the results should be very tasty.
I don't think anyone answered your Q re: calculating efficiency yet, unless I missed it, so here goes:

I take it you are using BrewMate or similar? This defaults to 70% efficiency IIRC.
So, if you started with the amount of grain and water you told the software you would, and hit the SG (before boil) the software predicted, your efficiency = 70%. If you had a higher OG, your eff. is > %70. If lower, the eff. is < 70%. BrewMate also tells you post boil gravity and volume. If your results differ but pre boil were correct just change "evaporation rate" in the settings until you find the correct one.
It takes a few brews to "dial in" your numbers, and these can change to depending on other factors - crush being one, process another, and I believe making "bigger" beers - ie: more grain, less water, will reduce efficiency.

ps.
One of the best things I have done was to get a measuring jug and a marking pen and mark 2 and 10 litre graduations on the sight tube of my urn. Lets me keep tabs on volume after hoisting the bag, boiling, etc.

Thanks Gard, the efficiency calcs is what I was trying to understand. To be honest I am still not 100% sure if I do now but I have a better understanding.

I have actually marked 1 liter increments down the sight tube for ease of seeing the water volume.

I was using Ian's spreadsheet and BrewMate

 

[stux]

Efficiency is how much of the potential grain sugar gets into your vessel

So 70% into fermenter/brewhouse means 70% of the sugars in the grain made it to your fermenter

Pretty good really

 

[Bribie G]

Very timely question, I just used my new urn for the first time this morning, worked a treat!

I used a bit of Bribie G's "Pressinator" method, and a bit of the squeeze method.

I put an old fridge shelf straight on top of the urn, as it was coming up to boil, then lowered the bag onto it.

Then, I used an old dinner plate on top, and pushed down, only took about 30 sec's, and no hot drips going down arms.

One question I have though, is how much should I be losing to trub? I stopped draining when the trub started going into the urn tap (I did whirlpool), but still ended up with 2.3 litres left.

Is this normal.

Thanks

With a bag you don't get a grain bed forming as such, so the first whoosh of wort out of the bag just comes mainly through the sides and you do end up with a lot more gunk in the kettle than with a "filtering" solution such as HERMS or Braumeister. This doesn't affect the quality of the beer so long as you use a good kettle floccer such as BrewBright. However that's why I've gone a step further and use a solid "bag" made from a 20L pail with a false bottom, that enables a true grain bed to form, and the wort gets "herded" through the bed as the solid "bag" is lifted.
Nothing wrong with standard BIAB so long as you are prepared for a bit more wastage. BIAB = simple and quick but no free lunches

Edit: in addition, the single biggest improvement you can make to wort recovery rates is not to put hops, including pellets, into the kettle commando style. I was doing that and found that, particularly with the low alpha hops, the bloody things breed in the kettle and turn into masses of mud. I now use a hop sock arrangement, one of these from Ross or another supplier makes a good hop swimming pool, just peg it round the top of the kettle, and allows the hops good circulation, as well as trapping nearly all the vegetable matter, even from pellets.

 

[bowie in space]

I hoist the bag after the mash and let it drain into the urn, then run about 6-8L of 78C water from the top of the bag down through all the grain, then squeeze the bag. I then take the gravity reading at pitching time. Using brewmate, I get around 75% efficiency.

Bowie

 

[technoicon]

I have done most things when it comes to BIAB, none of which I think make a huge difference.

I used to squeeze as soon as I hoisted the bag. now I just leave it while I start the boil. then just be for it's ramped up I squeeze what I can out of it.

I used to mash-out at 70 degree's for 10mins. Find this doesn't really do alot. so i have stopped doing this, still hitting the same gravity figures.

with larger beers to get efficiency I use another urn and move the grain into that pot after the mash, then join the two together. (kind of like a batch sparging)

I have used bags for hops, hated it. I emptied the grain and used the grain bag with a large spoon in it to hold the bag down. this worked ok.
Now I just throw the hops in. stir the wort after the boil is finished (whirlpool). leave for 10min. then pour into my cube. (I also cube hop)

I take a gravity pre boil, then take OG when pitching yeast (if I remember)

For me now it's more about keeping it simple.

I no-chill, basically what I have been told is that a little air is ok, I've never had the no chill do anything bad to my beer. because the wort is so hot, it should sterilize the cube. i'm sure the air does something to the wort over time, but i only keep them for a couple of weeks max anyway.

 

[insane_rosenberg]

For the record, I brewed inside using a Crown Urn with a concealed element and had no problem at all achieving and maintaining a rolling boil.

Niether did I... in the beginning!

Make sure that concealed element is nice and bright before each brew :icon_cheers:

 

[TroyNZ]

If you have a couple of spare shelves and a $8 Willow Washing Bowl then the BribiePressinator is an option as well:

:icon_cheers:

Cheers for that Bribie, used this method today and it worked a treat. I just did it straight into the pot (had to tie the top of the bag down as low as I could to stop it spreading out too much). I often looked at those trays next to the fridge and wondered if I could do anything with them.

 

[QldKev]

I found not to get too caught up on the efficiency numbers, unless you are getting really bad numbers like 50% etc. As long as you hit a consistent efficiency is all that matters, that way you can make a consistent beer and improve on it. If you are getting efficiency all other the place, your beer will follow. Depending on exact efficiencies the difference may only a dollar or two worth of grain.

On my brew rig I do have a separate sparge vessel (bowl / keg) with a rack in it, but the main reason is I push my kettle volumes to the max so I can't fit any more water in the initial water volume; so I might as well pour the water through the grain first. I tried squeezing the bag, and thought it was more hassle than it is worth. (I get 75% efficiency without doing it). Also I find in the 15 or so minutes the kettle takes to get up to the boil, a lot of the wort has drained by itself.

I think the main thing is do what you are comfortable doing, and what gets you consistent beer.

QldKev

 

[cam89brewer]

I hoist the bag after the mash and let it drain into the urn, then run about 6-8L of 78C water from the top of the bag down through all the grain, then squeeze the bag. I then take the gravity reading at pitching time. Using brewmate, I get around 75% efficiency.

Bowie

Sorry to be so dumb but how do you actually calculate the efficiency of a mash?

 

[stux]

Sorry to be so dumb but how do you actually calculate the efficiency of a mash?

This should get you there

Efficiency = GravityPoints * Volume_At_20C/(307 * Grain_Bill_in_KG)

307 is an average LDK for grain, which is a good estimate, ie 80% HWE

So,

5KG of grain, at Start of Boil you have 38.8L and 1.037

38.8L at 100C is about 38.8 / 1.04 at 20C = 37.3L (4% cooling shrinkage)

so,

37 * 37.3 / (307 * 5)

1391/1535 = 90.6% Into Kettle efficiency

Not bad

 

[QldKev]

Sorry to be so dumb but how do you actually calculate the efficiency of a mash?

We mash grains to extract the sugars
The Expected Gravity is based on a potential extraction in lab conditions. Known as 100% efficiency, this will give you a given Gravity potential for your recipe. (it's possible to exceed this number)
As home brewers we never gain the full potential extraction of the sugar

Brew house efficiency is basically your SG vs the labs SG

You can measure this with your hydrometer / refractometer / brixometer gravity reading and also the volume, and use the numbers against your recipe potential extraction in a brewing calculator / brewing software to work out the brew house efficiency.

We care about the efficiency as we are trying to brew to a given alcohol level, and also remember in simple terms hops = bitter & malt = sweet, it effects the balance of the beer. If you end up with a lower or higher gravity than expected you should adjust your hop schedule to suit. The problem is you end up with a higher / lower strength beer than expected. If you keep getting different gravities you then don't get a change to tweak the recipe to perfect it for your brewing system and get random quality beers. If you do undershoot the extraction a quick fix is adding a bit of dried malt extract.

Anyone can jag that pefect beer, but a good brewer & brewery will be able to consitently replicate it.

Hope this helps

QldKev

edit: Resource of some grain potentials
http://www.byo.com/resources/grains

 

[felten]

This is a great article to help as well. http://braukaiser.com/wiki/index.php/Under...ding_Efficiency

Might be a bit steep for a new brewer, took me a few reads before I got it.

 

[tavas]

I get 90% mash efficiency using a 2V BIAB setup. I heat all of my water in the urn and mash in an esky at about 2.5l/kg as per a normal mash. After an hour I drain the bag, then dunk sparge in the urn for about 15 mins. Hang the bag and drain while transferring the esky to the urn and start the boil. Bag can drain, then give it a squeeze to finish off. Consistently 90% on beers to about 1.050 SG, 80-85% on beers to 1.065. Haven't bothered going above that.

 

[cbet]

I get 90% mash efficiency using a 2V BIAB setup. I heat all of my water in the urn and mash in an esky at about 2.5l/kg as per a normal mash. After an hour I drain the bag, then dunk sparge in the urn for about 15 mins. Hang the bag and drain while transferring the esky to the urn and start the boil. Bag can drain, then give it a squeeze to finish off. Consistently 90% on beers to about 1.050 SG, 80-85% on beers to 1.065. Haven't bothered going above that.

I think I'll be giving this a go in my next brew. It sounds similar to the method described here but with esky + urn instead of two pots. Ralph claims to get 23L at 1.055 from 4.5kg of grain, which gives him just over 90% efficiency.

When you dunk sparge, do you open up the grain bag and give it a mix at all? Also, is it worth trying to keep a consistent temperature during the dunk sparge? I would have thought it would cool a lot in 15 mins if you do it Ralph's way without a lid.

I've done several BIABs now where I have poured a few litres of 75 degree water through the bag while it drains. I've been getting around 70% each time, which seems a little low compared to what others are reporting.