Brewhouse Efficiency....again

[MatthiasS]

Hi,

For a 10P beer I would have to stop the sparge 400-500l before kettle full if I'd stop at 2.0 plato which would be quite uneconomic. I know kunze says 2-3 but this is for Vollbier which is usually 5.2abv. Narziss has a different opinion and tbh I rate him higher than kunze. For industrial lauter process numbers for soluble extract are about 0.5% and soluble extract 0.8% I think and this is also for Vollbier. So I dont share your opinion here.

[Todd Hicks]

Hello everyone,

Quick update. I just wanted to correct the efficiency number from above which was actually lower because the pitential was 79.5%
((1.0382*9.55*3100*0.96)/400)/79.5 = 92.8% and not 95%

We did a lot of messing around with the tun and yesterday after a very controlled lauter tun run off procedure and a finer grist we got 94.5% (2760l at 10.45P) but our last runnings were still 2.0brix which means we are losing some extract at the end. Unfortunately we have to stop sparging because our evaporation is too low. If we could have put 150l more last runnings into the kettle the efficiency would have even increased more. At the moment we are seeing 2.5%....5% would be nice though. An efficiency of 96% would be brilliant.

Matthias

You really don't want to pull any runoff that drops below 2.0 P. It is undesirable grain particles, not sugar extract. When runoff is below 2.0 and you need to top off the brew kettle, it is better to just add hot liquor rather than final wort that is oversparged. Adjust the malt bill upwards in the next batch if needed to reach your target kettle gravity and volume.

[MatthiasS]

Hello everyone,

Quick update. I just wanted to correct the efficiency number from above which was actually lower because the pitential was 79.5%
((1.0382*9.55*3100*0.96)/400)/79.5 = 92.8% and not 95%

We did a lot of messing around with the tun and yesterday after a very controlled lauter tun run off procedure and a finer grist we got 94.5% (2760l at 10.45P) but our last runnings were still 2.0brix which means we are losing some extract at the end. Unfortunately we have to stop sparging because our evaporation is too low. If we could have put 150l more last runnings into the kettle the efficiency would have even increased more. At the moment we are seeing 2.5%....5% would be nice though. An efficiency of 96% would be brilliant.

We pulled really hard on the bed and compacted it quite a lot. The wort itself was quite clear but a lot of very fine particles still made it into the kettle. We have some gaps in the false floor. 4cm long and 2mm wide (about 6 of those). Do you think those fines come through these gaps? Like I said, the filter bed is quite compact so I cannot imagine that the fines losen within the bed, work its way through and then pass through the actual false floor but maybe through the gaps.... If we could get 96% and get rid of these fines I would be happy.

Matthias

[dick murton]

I know it shouldn't be, but it is not uncommon to get a few small particles of unconverted starch remaining in the grist, particularly from those particles at the top which are not fully immersed in water when using a mash tun as the mash rises a little (which I know is not the case when using a mash mixer and separate lauter - but just in case pure MT users note this).

95% is not bad at all from a small brewery system such as this. If you checked the runoff gravities every few minutes during vorlauf and after starting runoff to kettle, it is not at all uncommon to notice a small rise in gravity, and then a stable gravity before it drops off steeply. This is largely dependent upon the length of the vorlauf, but if your wort clarity is acceptable and you are getting decent runoffs, then I wouldn't panic about extending the vorlauf time as all you are likely to be doing is extending the whole cycle. Finer grist from a different supplier may help as you point out. With a 30 brl setup, consider buying a decent mill, which should allow you to get more consistent grist ratios (loads of complaints about variability from some suppliers) and perhaps improve efficiencies further.

[MatthiasS]

Hello,

Yesterday I brewed our IPA (1.060) and collected for 150min (vorlauf 10min). I pump the volume below the false bottom plus 50l back on top and the wort was more or less bright. I got 85% efficiency (expected 81%) and was quite surprised. Today with our pale ale I did the same but the runoff was even slower (180min). Efficiency was 95% in kettle full. (400kg malt, Extract potential 78.5%; 3100l hot wort with 1.0383) In the FV I ended up with 92.5% (2900l cold wort). The slow runoff worked. I also played around with the rakes and cut to 5cm above the false floor, which probably helped too to prevent channelling and bring the grains more in contact with the water. Last runnings were 0.8brix and pH 5.54. I took 1kg spent grain and mixed it with 1l of water....0brix. What I noticed was that the conversion efficiency was low. Potential was 18.2P in the first wort, I only got 17.4 though. I think the slow runoff did the trick but with a finer grind I probably can convert even more. Like I said, it is a mash tun grind and even after 30min 62c, 15min 72c and 5min 78c there were still starch lumps in the spent grains that have not been converted. In about 1 1/2 weeks I will brew the same beer but with the finer weyermann malt. Lets see if the conversion goes up.

Matthias

[MatthiasS]

Hi,

I see where you are coming from. I am not raking to loosen the bed because it is compacted too much (I could rrun off a 100% pilsner malt beer without any raking), I rake to prevent channelling and get a better spargewater grain contact. But even this does not increase my efficiency significantly.
Anyway, I will slow the runoff time down and see if that does the trick.
My LT occupation time is at the moment 2 1/2 hours
- 15min filling
- about 15min vorlauf
- about 75 - 90min runoff
- about 15min grainout

We mash in at about 7:30 and are done CIPing at 13:30, so 30min longer runoff would not matter. I would be more than willing to pay the price of a 30min longer brew day for 3-4% more efficiency.

[dick murton]

Slow the runoff down. 75 minutes is fast by any standards. Try 120 minutes. If this results in excessive working hours, then speed it up and accept the bulk of those losses. The problem with making the grist finer is that you may then have to slow the runoff down because otherwise you pull the bed down too fast and end up raking even more. I know loads of people on this site vorlauf for long periods, but major breweries vorlauf for 5 or 6 minutes only - basically enough to get the water wort from below the plates, and obviously some of the fines, transferred on top. Anything extra uses up time better spent running off to kettle, and helps to blind the bed unnecessarily.

[ERoss]

Sounds to me like the crush could be the issue. Can you specify to your supplier a range of crush? Where I order from we can specify fine, medium or coarse. Do you have a way of testing the crush of your grain on site?

Cheers,
Eric

[MatthiasS]

Hello everyone,

I am brewing on a three vessel 30hl brewhouse (mcv, lt, kettle/wp) and I am experiencing low efficiencies. The highest one I got was an all pilsener malt beer (1.036) with 90%. With such a system I would expect at least an efficiency in the mid 90s.

I mash in at 1:3.5 run a step infusion program with a mashout at 77C (mash ph 5.45 at the last brew), transfer into the Lt, start vorlaufing for 15min and once the wort is clear I start collecting. Once I start sparging I cut in 2cm steps from 22cm up to 12cm into the bed. My run off takes about 75min. Last runnings are below 2.0 brix....for a 1.040 beer about 1.8...for a 1.036 I've seen as low as 1.3. We buy our grain pre crushed and it is definitely not a Lt crush. It is very coarse. Do you think a finer grind would help? I am getting quite frustrated because I laid out the Lt for 95% and now we are only getting 90% which results in more grain that is needed and therefore a deeper bed which lowers the efficiency....vicious circle. We are getting quite clear worts with some bits....sometimes more sometimes less. In the wp we lose about 50l.

I think the culprit is the coarse crush. I am thinking about getting some Weyermann malt pre crushed which should be finer due to them crushing for german breweries and therefore Lts whereas the english maltings crush all for mash tuns.

The brewery I worked before got 99% with a wet mill and Lt but this was a Krones kit ;-)

Looking forward to your answers.