Beer Baron Posted January 9, 2019 Share Posted January 9, 2019 Hi everyone. I made a recipe last year and it came out at 6.4%. I entered the exact same recipe today for a batch that I am going to brew soon and the ABV is 5.9%. Does the grain value change annually?? Do I need to increase my grain at the same percentages to make the exact same beer?? Thoughts?? Link to comment Share on other sites More sharing options...
The Captain!! Posted January 9, 2019 Share Posted January 9, 2019 I recently had the same issue. With all agricultural materials, it will change harvest to harvest. Then the maltser will have a go and that could be slightly different from batch to batch too, then your mill size might be slightly different and therefore your efficiency is out. I adjusted my water amount slightly and got my efficiency back to where it should be. Could also be your mash temp, maybe higher? Accounting for less fermentable sugars. Link to comment Share on other sites More sharing options...
ben 10 Posted January 9, 2019 Share Posted January 9, 2019 different yeast, different volume? where did you enter said stuff? Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 9, 2019 Share Posted January 9, 2019 Sounds like a case of the brewing of the recipe not quite matching the software prediction? Happens all the time for me although usually not that much difference. Maybe comes out 0.1-0.2% different to the prediction. Link to comment Share on other sites More sharing options...
Greenyinthewestofsydney Posted January 9, 2019 Share Posted January 9, 2019 ABV variation depends on a lot of things. Even the big breweries have a 0.5% ABV margin i believe as it is inherantly variable. For example I have a belgian dark strong beer cold crashing at the moment where the OG was 1076. Was supposed to finish at 1010 ish like the last one but for some reason the yeast took it all the way to 1002. 9.1% ABV in the bottle it should have been but actual will be 10.2%. Same recipe. Same yeast. Same ferment schedule. The last one OG was 1078 to 1010 and this one 1076 to 1002. Wyeast also says 74 to 78 attenuation on this yeast as well. Its never been below mid 80s and this one was 97%. There attenuation numbers especially for belgian strains aint worth squat.. Link to comment Share on other sites More sharing options...
Beer Baron Posted January 9, 2019 Author Share Posted January 9, 2019 EXACTLY the same including batch, yeast and mash temps. I use the Grainfather app Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 9, 2019 Share Posted January 9, 2019 Are you saying the software predictions were different each time you plugged the recipe in, or that the 6.4% one was an actual measured figure from brewing and fermenting the batch? The latter would make sense, your OG may have been higher than the software prediction when you brewed it or the FG lower than the prediction. Was it bottled or kegged and does the app account for the ABV contributed by priming sugar? Software won't automatically change grain specs, you have to do it manually unless the grain father app is different like that. However, while the grains do vary slightly from season to season, I doubt they'd vary enough to change the ABV by that much. The first all grain lager I brewed turned out 1% higher in ABV than beersmith suggested when I constructed the recipe. The reason being the efficiency was still set to the default 70%, as I hadn't really measured my actual efficiency yet. Obviously the real life figure was higher. I changed it for the next batch and it came out on target. Link to comment Share on other sites More sharing options...
Beer Baron Posted January 9, 2019 Author Share Posted January 9, 2019 I made the recipe twice last year and it was predicted to be 6.4% and it came out at 6.4%. This time when I enter it’s predicted at 5.9% and I am 100% sure I have the exact same recipe. My efficiency is 75% and I’m always pretty much at that target. I only keg so no priming is required. Link to comment Share on other sites More sharing options...
Beerlust Posted January 9, 2019 Share Posted January 9, 2019 Do you log each of your brews for future reference? Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 9, 2019 Share Posted January 9, 2019 You must have done something different, left out a grain or added less base malt or something. It shouldn't change if it was entered the same. Every time I make a pale ale I put the same grist, mash temp and yeast in and get the same predicted OG, FG and ABV. Link to comment Share on other sites More sharing options...
Beer Baron Posted January 9, 2019 Author Share Posted January 9, 2019 I log each brew and I’m 100% sure it’s the same. There is a copy brew tab Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 10, 2019 Share Posted January 10, 2019 Do you have any screenshots of each one? Maybe one of us can spot a difference. Link to comment Share on other sites More sharing options...
Beer Baron Posted January 10, 2019 Author Share Posted January 10, 2019 This is the first batch and was originally predicted at 6.4% and came out at 6.4% Link to comment Share on other sites More sharing options...
Beer Baron Posted January 10, 2019 Author Share Posted January 10, 2019 The next batch which predicts 5.9% Link to comment Share on other sites More sharing options...
King Ruddager Posted January 10, 2019 Share Posted January 10, 2019 Are there any other variables that could have changed, such as losses or boil-off rate? Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 10, 2019 Share Posted January 10, 2019 I can't see any difference between the two in those pictures. Were you still bottling when you first brewed it? Or is there a bottle carbonation option on the app that may have been selected for the ones that it predicted higher ABV? Link to comment Share on other sites More sharing options...
King Ruddager Posted January 10, 2019 Share Posted January 10, 2019 Ooh, does it tell you the pre-boil gravity of each? Link to comment Share on other sites More sharing options...
Beer Baron Posted January 10, 2019 Author Share Posted January 10, 2019 No boil off rate or pre boil gravity listed and I have always kegged since going all grain Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 10, 2019 Share Posted January 10, 2019 Well buggered if I know then. Brew it as you always have and see if it comes out at 6.4% again. The only other thing I can think of is if there was an update to the app that may have changed the way it calculates ABV. What is the OG and FG of the recipe? Link to comment Share on other sites More sharing options...
Beer Baron Posted January 10, 2019 Author Share Posted January 10, 2019 I am absolutely lost too. I’ll just brew it soon and see what numbers I get. OG 1.054 FG 1.010 Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 10, 2019 Share Posted January 10, 2019 Using the formula I run with it comes out about 5.8% from those figures. Not sure where they're getting 6.4 from Link to comment Share on other sites More sharing options...
Beer Baron Posted January 10, 2019 Author Share Posted January 10, 2019 14 minutes ago, Otto Von Blotto said: Using the formula I run with it comes out about 5.8% from those figures. Not sure where they're getting 6.4 from Maybe it was wrong all along........but why did I get 6.4% when I brewed the other times Link to comment Share on other sites More sharing options...
Otto Von Blotto Posted January 10, 2019 Share Posted January 10, 2019 Maybe your real life OG and FG were different from what the app predicted. That would be the only way it could be different. There are a few different formulae for calculating ABV but they usually only differ by 0.1% or so. Link to comment Share on other sites More sharing options...
King Ruddager Posted January 10, 2019 Share Posted January 10, 2019 Could be a change in the fundamental laws of physics governing our universe? Link to comment Share on other sites More sharing options...
The Captain!! Posted January 10, 2019 Share Posted January 10, 2019 There’s the true answer right there Link to comment Share on other sites More sharing options...
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