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A Litttle Guidance on Cream or Oatmeal Stouts, please?
slower sparge? pour the water slower? more or less temp or water? how do you figure efficiency?
ID
Rubberchrist wrote:
All right. It's in, it's pitched.
Came out to approx: 1.048-1.050 SG, which is about 8 points low for what I was hoping, but whatever. So long as I wind up with about 4%, I'll be a happy boy.
It does put my bag mashing at about 60% efficiency, though, which I'll need to refine.
Might not get much better. I had about the same using a bag to mash. How much water per pound of grain did you use to mash? Also how much did you sparge with?
I found that paint strainer bags are good for mashing as they have more room. if the bag is tight at all it will really hurt. you almost need a bag that you can fit the brew pot in and you'll likely have to make one that size.
when I sparge I put the bag of grains in the brew pot and pour the sparge water onto of the grains, bag and all, make sure the bag is real loose and stir it for a minute and let it sit for 5 minutes then remove bag into another pot and while heating up the wort to boil periodically pour anything that's drained from bag into the brew pot.
Best efficiency I got was not using any grain bag and did a 3 gallon all grain and got 70%. Only done 3 all grains so I need more practice.
Other things to consider:
1) temp of wort when taking hydrometer reading. don't forget to account for temp difference. every 10 degrees above 60 degrees add .002 to .003 to hydro reading.
2) wort might not have been mixed thourghly with the water so you might be getting an inaccurate gravity reading.
3) Next time if you're sure your reading is correct but low you can boil some DME and add it to correct gravity reading.
DC
Irondavy wrote:
slower sparge? pour the water slower? more or less temp or water? how do you figure efficiency?
ID
Your method would need to be explained a bit clearer- but I am assuming you are mashing in the bag, rinsing the bag, then yanking it to leave behind your sweet wort. If so, how long are you letting the mash sit for a saccharification rest? Are you sure you are getting full conversion? When sparging, what is the temp of your rinse water? Are you sure the water is pouring over all the grains to rinse and release the sugars?
To calculate efficiency you can either use a brewing chart to determine your volume's potential extract, then you divide this into the actual extract to get a ratio of efficiency percentage.
So you need to calculate each ingredient then add them all up. A simplified example would be 2 row ale provides 38 gravity points per # per gallon. So 6 #s in a 5 gallon batch would produce 6 x 38 / 5, or 45.6.So 45.6 gravity units equals a potential extract OG of 1.046 (rounded) If your system was perfect it would produce this. It is impossible for a system to be perfect, so we strive for a happy medium of proper sparge water temp (170 at grain contact) and system loss, to try and get 75-85% efficiency. To calculate this, take your actual OG you got from the postboiled, cooled wort, and divide that by its potential.
So in our example, say you did this mash and got a postboil cooled reading of 1.035. You would divide 35 / 46 and get .76, or 76% efficient. This is called mash efficiency. There is also brewhouse efficiency which is always slightly to largely lower, this factors in equpt loss as well.
If your system is not largely efficient and you are only extracting 50-65% potential, it is no big deal, you just need to use more grains to make up for the lost sugar. This is all much much easier if using brewing software, I recommend messing around here: http://www.tastybrew.com/calculators/recipe.html
You can change that efficiency % field to whatever you think your system is providing, then build your recipes grain volumes based off of that. Print it when you are done, then when you brew that batch, match up the figures and see if you are higher or lower than your target OG, replicate the same recipe, but change the efficiency % until the real OG is met, this will tell you exact.
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