BIAB Excessive Trub

[MHB]

Pratty, Pro brewers use the term Brewhouse Efficiency differently to the way most home brewers (mis)use it, I prefer the slight less confusing term Brewhouse Yield, same thing.
Brewhouse efficiency is the same a mash efficiency
Brewery Efficiency is the overall efficiency of the hot side.
Mark

 

[Dan Pratt]

MHB, much thanks.

I knew it would be soon enough you entered the topic.

Im brewing on overall efficiency which is why 90% seemed unlikely.

 

[Lyrebird_Cycles]

Hi, that's 24.2kg of wort. How many litres is that?

You can calculate the litres by dividing the mass given by the SG which in turn can be derived from the oP given.

In this case 13.3 oP ~= 1.054 so 24.2 kg ~= 23 l.

To save you the trouble, Brewer's friend gives that as 84.5% efficiency and these figures are for clear wort into the fermenter(s). That was the first brew on the new system and included a small loss from spillage. I was very disappointed with that result and when the next two also came in below 90% I decided to rebuild the system (again), the new lauter plate is evidently not working*.

The re - rebuild is not going well BTW, I've built two new plates and trashed them both. Third time lucky.


* That's not the only symptom, it's also not clarifying the forerunnings properly which is why I think it's the lauter plate that's at fault.

 

[Lyrebird_Cycles]

I really feel LC you are getting yield of extraction from the malt mixed up with brewhouse eff.

I agree that the term "brewhouse efficiency" is capable of misinterperetation.

As MHB says above, in my previous work I have used it to mean what might more properly be termed "brewhouse efficiency minus trub losses", eg if I say that this is 96% I mean

(final wort mass post boil x wort oP) / Σ (malt mass * extract FGDB * (1 - moisture)) = 0.96.

I have tried to make it clear when I mean "brewhouse efficiency with losses" if I say this is 90% I mean

(final wort mass in fermenter x wort oP) / Σ (malt mass * extract FGDB * (1 - moisture)) = 0.90.

The figures were chosen to be representative of what I consider achievable efficiencies at small scale. At commercial scale they'd need to be 2-3% above that.

 

[Lyrebird_Cycles]

Brewhouse efficiency is the same a mash efficiency

Not sure I agree with this.

Mash efficiency is derived from comparison with the FGDB formulae in EBC Analytica 4.5.1 so it's basically

(Mash oP * (mash liquor mass + malt moisture mash)) / Σ (malt mass * extract FGDB * (1 - moisture)).

The difference between this and brewhouse efficiency as defined above comes down to the effectiveness of the lauter tun.

 

[MHB]

Well the same as what most home brewers mean by mash efficiency
Or how much extract you get over how much there is there to be got (yield from test) as a percentage

 

[Stieger82]

What % of trub are other people getting in the final boil volume? Just wondering.

After draining the cooled usable wort (Little trub) from my kettle into the fermenter, I then get 3.5-4L of wort/trub left. If i let this settle, the trub would be about 1.5L.

So for me:
Total water needed = 32.8L
Grain Absorption = 1.4L
Starting Boil = 31.3L
Boil off = 5L (60 min)
Wort loss due to excess trub = 4L
Hop Absorption = 0.3L
Fermentor Amount = 22L

 

[nosco]

^That seems like a lot. I had 4.5lt of trub uncooled out of the kettle with a 48lt batch, BIAB into no chill, last week. Thats with 70g of hops thrown in and with stirring in between for a step mash. A slow lift with no mash out. A bit more will settle in the cubes i think but it was very clear wort.

Hefeweizen. Just a normal crush as always.

Edit: 11.017kg of grain and 75lt of total water.

 

[Stieger82]

^That seems like a lot. I had 4.5lt of trub uncooled out of the kettle with a 48lt batch, BIAB into no chill, last week. Thats with 70g of hops thrown in and with stirring in between for a step mash. A slow lift with no mash out. A bit more will settle in the cubes i think but it was very clear wort.

Hefeweizen. Just a normal crush as always.

Edit: 11.017kg of grain and 75lt of total water.

Its not exactly 4.5L of trub but rather a mix of wort and trub i'd rather not go into the fermentor. I could reduce it to about 2L if i passes it through a strainer

 

[nosco]

Makes sense. I did actually get an extra 2lt to use in the starter. I think the larger diameter of bigger kettles helps flatten the trub out. It makes it easier to get more wort.

 

[Stieger82]

My kettle unfortunately is now my old mash tun which i designed to be completely drained. I have an elbow welded into the lowest point and a tap for draining. This was great for mashing the traditional way but a slight downside for BIAB brewing. I am going to further modify my system by getting rid of the grain bag and replacing it with a stainless basket that is used in the robobrew system and also install a pump to recirc the wort during the mash (hopefully a more gentle way to maintain temp). I can also use this to recirc the cooled trub/wort through the hop spider to further filter out.

 

[fdsaasdf]

I can also use this to recirc the cooled trub/wort through the hop spider to further filter out.

I hadn't thought of this as a way to filter and aerate wort at the same time - could work quite well. Pretty much all my keg king hop spider is used for these days is to filter sediment between mash and boil, then filter trub during my recirculating hop stand. The mesh size is too fine for decent hop utilisation (after 20+ brews).

 

[Stieger82]

I hadn't thought of this as a way to filter and aerate wort at the same time - could work quite well. Pretty much all my keg king hop spider is used for these days is to filter sediment between mash and boil, then filter trub during my recirculating hop stand. The mesh size is too fine for decent hop utilisation (after 20+ brews).

I am also questioning the use of the hop spider due to this. I have not taken a temp within the hop spider but it can be hard to get a nice boil within it. I think a hop sock would work better. I am also going to ditch the hop bag during dry hopping and dry hop loose, anyone made any comparisons between either?

 

[Matplat]

I would definitely recommend dry hopping loose.... just cold crash to sink the hops before packaging.

 

[hotmelt]

A $5 trub ring worked for me till I moved my temp probe in the way of it.
http://aussiehomebrewer.com/topic/90101-biab-tipping-boil-dreggs-into-the-fermenter/page-2#entry1357694

Although according to LC's link I'm getting 82-86% efficiency without it.


So I ended up with 24.675kg @1.046.I think the fact I mashed in at 8pm and left it recirculating till 6am might have helped. I don't lift the bag either I drain it into pails.

After draining.

 

[Lyrebird_Cycles]

On those figures I get about 79%. Did you by any chance enter the mass as the volume? If so that will overstate efficiency by 4.6%

 

[hotmelt]

On those figures I get about 79%. Did you by any chance enter the mass as the volume? If so that will overstate efficiency by 4.6%

Guilty.
If I add a litre from the jug it works.

 

[Bribie G]

Ok gents, back on track.
The OP was complaining about excessive loss to trub, then the thread turned into a chalk and blackboard debate about efficiency.

So returning here to the coal face, here's a brew that I did yesterday afternoon. Fair grain bill of 5.8kg in a 25L batch - the 25L would include trub.

No stirring or paddling after the mash, just let it rest. Gentle lift while ramping up to boil. Five minute hoists on a timer.



At the end of the lift, squeezing results in clear wort (ed running out of the bag, as a grain bed has been formed in the bag. I'm a squeezer.

Then when it reaches the boil - first there is a cap of foam and in the case of BIAB compared to maybe HERMS or BrauMeister there is a bit more foam, and that's not break it's just "fines" and other muck. When the boil has broken through the cap of foam it distributes it around the sides of the urn where it sticks there pretty well, thus removing that source of trub.



Now I reach for the Craftbrewer grain bag - not a BIAB bag, a grain bag - and peg it round the lip of the urn and add hop pellets. The bag goes deep into the wort and as it billows during the boil, the hop material gets a good "massage" and extraction. Bag is hoisted on the pulley and left to drain.

See later for a photo of the hop residue.



At the end of the boil, BrewBright then rest with lid on for 25 minutes and fill cubes, keeping an eye on the stream to avoid any transfer of trub.
This is what was left in the urn this morning.



Onto next post, reached attachment limit.

 

[Bribie G]

I poured all this into a jug half an hour ago, leaving the following in the urn. Note the ring of trub that sticks above the wort and actually gets marooned there during the boil as the wort level drops. In addition I do a final "foam up" of the wort and much of the break ends up attached to the lid of the urn and the sides, thus removing a further amount of trub.



Contents of jug after 30 mins settling.



Total loss to trub around 700ml - but on further settling I'm quite confident that I'll only lose 600. The clear wort will be reboiled, diluted and used for my starter for this brew - will crack out the stir plate later.

And here's the contents of the hop "swimming pool". Pretty well leached out.



So, 500 - 700 ml trub loss, not two or three litres.

As posted in an earlier thread, anyone doing BIAB and experiencing unacceptable loss to trub doesn't need to invest in extra time, work and equipment. It's all in the process.

 

[ScottyDoesntKnow]

This is all I do... bit of left over Swiss voile in a pasta strainer sat on top of the fermenter and pour the kettle through it. I don't bother with a hop spider or anything anymore, seems to give me pretty clear wort, might have to stop once or twice to empty the strainer but it's easy.