Can someone try to explain why all of my recent brewing results are 6-10 points higher the declared O.G ? The declared O.G. is taken from a all-grain kit from the same source: 9/10/12 - English Brown Ale declared 1.050 resulted 1.058 - mash 154F / 60 min 9/15/12 - English Mild Ale declared 1.043 resulted 1.052 - mash 154F / 60 min 9/22/12 - California Common declared 1.054 resulted 1.064 - mash 152F/ 60 min In general its all-grain, using mash tun in the acceptable temp rang, one step infusion mash.
Are you hitting the same volume as declared in the kit? Perhaps you're just boiling off more than they did. Did you take a pre-boil gravity reading?
Check the recipe closely and attempt your own calculations. Often, the estimated OG for a recipe presumes a certain brew house efficiency. I have often seen 70% or 75% for this number. If your actual efficiency extracting the sugars from the malt is consistently higher, you can predict your OG more accurately either with your own calculations, or by adjusting that one factor in the prepared recipe. Also, double check your hydrometer to ensure that it is accurate and readings are corrected for temperature.
Take note of your preboil volume, preboil gravity, post boil volume, post boil gravity, and volume into the fermenter. Accurately recording these will help you to determine your mash extraction efficiency and brew house efficiency for each brew day. Knowing these percentages will help you map out your losses plus dial in your recipe formulation / targeting goals.
If your volumes are correct and your OG is higher than the kit is stating then your extraction efficiency is higher than the kit is assuming. For example, maybe the kit assumes 65% efficency but your system is getting 75%.
Thank you, its an eye opener for me, first I tested my hydrometer on tap water => 1.000. I keep the target volume declared in the kit (5 gal pre boil) I have never measure or log pre-boil gravity just because I am not holding 100% wort before the boil. first 2th and 3th running is already on the stove, the rest of the wort will join latter using the sparging result. only then i will have 100% wort, but at this point I have started heating the wort.
My guess is that HB42 has it ( I know, shocking huh?). It's just likely that the OG estimate for the kits is based on a number lower than what you get at home. For example, many of the big homebrew stores use 70% for their base. I typically get 82-83%. Obviously, those expected OG numbers will vary, sometimes significantly. Over time you'll get used to what your home brewery provides and will be able to adjust accordingly. This is where having your own spreadsheet or using a computer program really comes in handy. Set either to your usual efficiency, plug in the grains in the kit, and see what you can expect from your setup.
Recommended reading... http://hbd.org/uchima/tech/efficiency.html http://www.howtobrew.com/section2/chapter12-5.html http://beersmith.com/blog/2008/10/26/brewhouse-efficiency-for-all-grain-beer-brewing/
