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  • Brewhouse Efficiency....again

    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.
    Last edited by MatthiasS; 10-11-2017, 01:35 PM.

  • #2
    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

    Comment


    • #3
      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.
      dick

      Comment


      • #4
        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.

        Comment


        • #5
          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

          Comment


          • #6
            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.
            dick

            Comment


            • #7
              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

              Comment


              • #8
                Originally posted by MatthiasS View Post
                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.
                Todd G Hicks
                BeerDenizen Brewing Services

                Comment


                • #9
                  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.

                  Comment


                  • #10
                    Originally posted by MatthiasS View Post
                    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.
                    As always, your mileage may vary. Also to say, the proof is in the pudding. If oversparging versus top off water gets you a clean beer without tannin astringency, then that procedure is working for you. In the end, how does it taste? Are you getting astringent flavors, grainy bitterness, or added polyphenol characteristics? If possible, brew two batches with both procedures and compare them.
                    Todd G Hicks
                    BeerDenizen Brewing Services

                    Comment


                    • #11
                      Originally posted by Todd Hicks View Post
                      As always, your mileage may vary. Also to say, the proof is in the pudding. If oversparging versus top off water gets you a clean beer without tannin astringency, then that procedure is working for you. In the end, how does it taste? Are you getting astringent flavors, grainy bitterness, or added polyphenol characteristics? If possible, brew two batches with both procedures and compare them.
                      Of course a "first wort beer" (without any sparging) would be of highest equality but it also would be completely uneconomical for a commercial brewery. The more you sparge the more economical your brew gets and at the same time your quality suffers (up to an extent). My point is that if you try to increase your efficiency up to 4% to save £50k and more a year it does not make sense to stop the sparge at 2P. If I am not a commercial brewer I would not care about efficiency, but I am so my goal is to find the sweet spot between quality and efficiency. Every sophisticated german mcv, lt, kettle, wp system achieves 97-99% efficiency. I will not chase the last 2% efficiency points but from such a system I think 95% should be easily achievable even if it does not have the most recent engineering behind it like the German systems do.

                      I think my beers taste good but a triangle test would be probably worth carrying out

                      Comment


                      • #12
                        I am not sure where the conversation switched to "first wort beer" without sparging. That is another topic best saved for discussion about historic brewing techniques and old beer styles.

                        I consider "oversparging" to mean - running sparge water past the point of necessity. Depending on the volume of the mash, the brewer should be able to cut off the sparge water during the lauter at the final stage of wort collection. Wort collected below 2P does not contain much fermentable sugar and those 2P of solids are mostly made up of tannins and husk material that you do not need in your wort. It would be better to stop collecting when wort drops below 2P and just top off the brew kettle with sparge water to reach your pre-boil kettle volume. By the end of boil, if your grain bill formula is correct, you will have reached your expected 10P or whatever and a post boil kettle volume to achieve a fermenter full of wort that will eventually yield your expected batch size or slightly higher.

                        With that long run on sentence, I offer a few extra suggestions.

                        Forget about efficiency calculation. These really only make sense in the laboratory when calculating the potential yield of the grain itself. It is not much of an indicator of brewhouse and brewer performance. This leaves the brewer chasing a number that probably doesn't exist. Switch for a calculation that tells you % Utilization of Extract by weight. It is an easier number to work with. This is basically degrees plato of wort per volume by dry weight of grist. A good target to start with will be about 65% and an efficient brewhouse can yield up to maybe 70%. I will look up the formula that I use and post here sometime. Improving %U is the efficiency gains that you should be the goal.

                        For improving gravity yield, stop the sparge before all of the wort if collected but where there is enough sparge water saturated in the mash to still run off your intended kettle volume without drawing heavy grain particles. I find that this will yield a slightly higher final wort gravity, maybe 2.0P or slightly above.

                        Raising the mash temp at the end of sac rest to a mash out temp will help with lautering. Start the vorlauf slowly and run until clarity is acceptable. Start lauter slowly and only begin sparging when the liquid wort level on top of the mash has dropped till you see the grain bed. Maintain about an inch of sparge water on top of the grain bed, avoid fluctuations in sparge temp or volume. You can increase the rate of wort collection slightly when you are about 2/3 full in the kettle - adjust sparge rate as needed. Stop the sparge at the point where there is enough water in the mash to collect your full wort boil volume if possible. Discard wort that drops much below 2.0P and top off the kettle with sparge water if needed to reach kettle volume - if you will be short of your 10P original gravity at the fermenter, you probably need to adjust the grist.

                        Check your water chemistry. Make sure you are getting an acceptable mash ph. Check sparge water ph. Check temperature gauge calibration. Make sure your kettle volume marks are correct. Check the mill; maybe the roller gap is out of calibration or it is letting whole kernals through. Maybe grist is getting stuck in the hopper or auger somewhere and isn't making it into the mash. Maybe collection pipes in lauter tun have a clog.

                        Hope this helps. At the end of the day, you should be hitting your target OG and yielding to bright slightly above the rated volume of your brewing system.
                        Todd G Hicks
                        BeerDenizen Brewing Services

                        Comment


                        • #13
                          I used first wort beer as the extreme end of the "stop collecting below 2P" spectrum because in this case you would not sparge at all so you'd get the highest quality wort. Stopping collection at 2P is uneconomic and if you want to improve efficiency not reasonable. The grain potential determined in the lab (e.g. 79.8% extract as is) can not only be reached with a highly.modern lautertun but even exceeded with a mash filter, simply because they don't extract the maximum possible in the lab. The efficiency numbers you posted are very low and a brewhouse getting 70% efficiency is definitely not efficient. With a potential of79.8% this would only be 87% yield. Brewhouses with lauter tuns that are designed properly and have good mechanics and engineering behind it can easily get 78% but they definitely don't stop at 2P.

                          Comment


                          • #14
                            Originally posted by MatthiasS View Post
                            I used first wort beer as the extreme end of the "stop collecting below 2P" spectrum because in this case you would not sparge at all so you'd get the highest quality wort. Stopping collection at 2P is uneconomic and if you want to improve efficiency not reasonable. The grain potential determined in the lab (e.g. 79.8% extract as is) can not only be reached with a highly.modern lautertun but even exceeded with a mash filter, simply because they don't extract the maximum possible in the lab. The efficiency numbers you posted are very low and a brewhouse getting 70% efficiency is definitely not efficient. With a potential of79.8% this would only be 87% yield. Brewhouses with lauter tuns that are designed properly and have good mechanics and engineering behind it can easily get 78% but they definitely don't stop at 2P.
                            % Utilization is not the same scale as % Efficiency. It is a measurement of the equipment and practices of the brewer versus the measurement of the grist.

                            I'm out.

                            If you want that extra 2P of husk solids and tannin, just go out and buy a mash press and a centrifuge to spin out every drop of wort.
                            Todd G Hicks
                            BeerDenizen Brewing Services

                            Comment


                            • #15
                              Hi,

                              I do not want to let this thread fall asleep so I make some further comments.

                              Today we reached with an improved lautering process 94.7% with a coarse mash tun crush. This means that with our own mill and a finer optimised lautertun crush we should reach at least 96% if not more. Washable extract was 0.6brix and all without a mash press...just with a process that whole middle Europe uses and Krones advertises with. But they clearly don't know what they are talking about.

                              We get so good firswort to second runnings separation that we drop from first wort concentration to 2-3P in about 10 - 15min. This means we would have to top up with about 40% of our kettle full volume with water. I might waste these 18kg of undesirable extract in my next brewer life when my aim is to make really good beer and not focus on efficiency and money so much. Because this is not really craft and everything below 2.0P is not allowed in my tripple double spelt rye wheat chocolate vanilla milk stout cinnamon ipa.Or I just buy a mash filter and get even lower washable extract values.....so many options.

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