MitchBastard Posted August 23, 2019 Share Posted August 23, 2019 Today I did an all grain Pilsner. 97% Pilsner 3% carapils 19L mash 17L sparge 90min boil i had a pre boil grav of 1.052 i had a post boil grav of 1.040 i had the desired 23L of wort left over after the boil. Beer smith predicted an OG of 1.050 whered me 10 point bugger off too.... could the temps of my measured samples played a part in this if they’re were too hot or cold? TIA Link to comment Share on other sites More sharing options...
Worthog Posted August 23, 2019 Share Posted August 23, 2019 For me, Beersmith3 predictions of OG etc are wrong because I do not have the correct process inputs, which are a mystery to my BIABing self. I just know my mashing process and what I'm going to get based on that process, and grain type and weight. I'll leave it to the Beersmith boffins to attempt to solve your problem, which would be innacurate input and process selections. Cheers 1 Link to comment Share on other sites More sharing options...
The Captain!! Posted August 23, 2019 Share Posted August 23, 2019 46 minutes ago, MitchBastard said: could the temps of my measured samples played a part in this if they’re were too hot or cold? Yep. Sure does. Clearly if your preboil og was 1.052, after boiling off water, the gravity will be more. 2 1 Link to comment Share on other sites More sharing options...
MitchBastard Posted August 23, 2019 Author Share Posted August 23, 2019 (edited) @The Captain!! I’ve just realised my brew house efficiency in my equipment profile is set to the default of 72%..... considering I haven’t worked out the bugs yet this would be too high?... changing to 60% puts me on the est OG of 1.040..... however it throws my pre boil grav way out at 1.036 Edited August 23, 2019 by MitchBastard Link to comment Share on other sites More sharing options...
Beerlust Posted August 23, 2019 Share Posted August 23, 2019 Hi Mitch. You only list grain percentages, what was your total grain weight(s)? Also, I was under the impression (as a general rule) BIAB'ers aim to full volume mash, so then don't require a sparge? It's early days for you in this area Mitch, & there is a learning curve where you begin to dial in & fine tune your methods in with the equipment & volumes you personally use. Everyone is slightly different. They are commonly referred to by the names "mash efficiency" & overall "brewhouse efficiency". Once you learn to understand these two areas of your brewery a little better, predicting OG's & FG's etc. using certain grain weights will become easier. Just make sure you document everything you can on each brew, as this will help you moving forward. Cheers & good luck with the brew, Lusty. 1 Link to comment Share on other sites More sharing options...
MitchBastard Posted August 23, 2019 Author Share Posted August 23, 2019 @Beerlust thanks Lusty, greatly appreciated. total grain weight was 5kg Pilsner malt and 150g of the carapils. Im using a Guten so no BIABing for me! Link to comment Share on other sites More sharing options...
Beerlust Posted August 23, 2019 Share Posted August 23, 2019 Gotcha. It would be interesting hear from AG'ers on their efficiencies with this grain mix on a similar setup & process. Cheers, Lusty. Link to comment Share on other sites More sharing options...
Beer Baron Posted August 23, 2019 Share Posted August 23, 2019 Were you drinking when you took the readings 2 Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted August 23, 2019 Share Posted August 23, 2019 Yeah, just no. You can't reduce the SG by boiling. It's literally impossible; sugar doesn't boil off so you have the same amount of sugar in less water, therefore a higher SG. You need to accurately measure the pre boil and post boil SG and volumes. The pre boil volume is important as well as the fermenter volume. If the pre boil volume is too low, you can top it up with a bit more sparging, if it's too high you can extend the boil, or keep the boil the same and get a bit extra volume into the fermenter at a bit lower SG. Take the temperature of the SG samples when you read them, and correct the readings if necessary. That will prevent crazy readings like you have here. I downloaded an app called convert everything which I use for this temperature correction, among other random things. It's a pretty handy app actually. For it to be reading that low post boil you must have taken the reading at bloody 70 degrees or something I don't know what the boil off rate is with those units but I'd guess the OG would actually be more around 1.060-62, maybe a little higher. 1 Link to comment Share on other sites More sharing options...
MitchBastard Posted August 23, 2019 Author Share Posted August 23, 2019 8 hours ago, Beer Baron said: Were you drinking when you took the readings No but may as well have haha Link to comment Share on other sites More sharing options...
MitchBastard Posted August 23, 2019 Author Share Posted August 23, 2019 @Otto Von Blotto cheers mate. Haha sample definitely wasn’t 70 degrees.... I believe that both samples were a touch over 20. The post boil probably a little higher of the two but Not too far apart. A combination of dodgy temps, a dodgy hydrometer and a dodgy brewer makes for an interesting brew day. Link to comment Share on other sites More sharing options...
MitchBastard Posted August 23, 2019 Author Share Posted August 23, 2019 Seems as though my OG is 1.040 guess I took a wrong reading pre boil? Link to comment Share on other sites More sharing options...
Popo the Reprobate Posted August 23, 2019 Share Posted August 23, 2019 If I don't give it a good stir after my mash and sparge I get some strange readings - both above and below predictions. 1 Link to comment Share on other sites More sharing options...
The Captain!! Posted August 24, 2019 Share Posted August 24, 2019 What was your volume @MitchBastard? 1.040 is quite low for 5.15kg of grain Link to comment Share on other sites More sharing options...
MitchBastard Posted August 24, 2019 Author Share Posted August 24, 2019 43 minutes ago, The Captain!! said: What was your volume @MitchBastard? 1.040 is quite low for 5.15kg of grain I’ve got 23 in the fermentor. When I made this post I thought I had 22 in the cube and a litre left in the guten making it a 23L batch. Turns out I’ve got 23 in the cube and a litre left over making it 24 after the boil which is a litre more than desired. Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted August 24, 2019 Share Posted August 24, 2019 Fermenter volume is the batch size, not what's in the cube or the post boil volume in the kettle. My next batch will be 21 litres in the fermenter. There's probably 22 in the cube, and there was about 25.5 in the urn post boil prior to transfer. You need to allow for kettle trub loss, all that cloudy, sludgy shit at the bottom gets left behind in the kettle. 2 Link to comment Share on other sites More sharing options...
MitchBastard Posted August 24, 2019 Author Share Posted August 24, 2019 @Otto Von Blotto yep got the batch size fermentor/vol bit. Been basing my input into beer Smith as a 23ltr batch size. This morning when I dumped the wort into my fermentor it came up to the 23ltr mark. Ive got 2.5L under my tap in the kettle so with that and the additional 1L I drained out before it started sucking, once the cube was full....that makes it 3.5L ontop of the 23L that went into the cube... 26.5 in total. I thought beer smith took into account that dead space of 2.5L ? Sorry fellas rookie here. Probably not explaining myself the best. Link to comment Share on other sites More sharing options...
MitchBastard Posted August 24, 2019 Author Share Posted August 24, 2019 2 hours ago, Popo said: If I don't give it a good stir after my mash and sparge I get some strange readings - both above and below predictions. I didn’t do this Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted August 24, 2019 Share Posted August 24, 2019 There should be a setting in Beersmith where you can input the losses in your system. I think mine is set at 3.5 litres for trub loss. I don't really count the bit of trub that gets left behind in the cube though. My cubes are different depending on the size too. With the 20 litre ones I usually have around 5-6 litres extra in the urn before transferring and that pretty much fills it to the brim, but with the 25 litre ones I need at least 6 litres extra in the urn, otherwise it falls short in the cube. Link to comment Share on other sites More sharing options...
PaulW31 Posted August 29, 2019 Share Posted August 29, 2019 (edited) On 8/23/2019 at 6:38 PM, MitchBastard said: @The Captain!! I’ve just realised my brew house efficiency in my equipment profile is set to the default of 72%..... considering I haven’t worked out the bugs yet this would be too high?... changing to 60% puts me on the est OG of 1.040..... however it throws my pre boil grav way out at 1.036 You really should be able to get 75% without trying, and 80% isn't really difficult. Stir your grain well for several minutes before the mash and take your time sparging. Edited August 29, 2019 by PaulW31 3 Link to comment Share on other sites More sharing options...
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