Iueelyen said:
Sorry, I don't completely understand the efficiency differences.
Brewhouse efficiency is the percentage of total possible sugars that make it into the fermenter.
Mash efficiency has two parts: Conversion and Sparge.
Conversion is simply how much starch is changed into sugar. You can measure this by the gravity rise during the mash. Once the gravity stops rising for 15 minutes, you're done. You can then compare the gravity to a chart and see if you have 100% conversion. Less than that and you may have crush or pH issues.
Sparge efficiency is how well you rinse the grain of the converted sugar. This is measured after the sparge by adding a measured amount of water to the drained, spent grain bed, waiting a few minutes and measuring the gravity. This is compared to another chart. Simply, the lower the gravity, the more sugar ended up in the kettle.
We simplify sparge efficiency by looking for full conversion, then measuring the preboil kettle volume and gravity. This is a sum of both efficiencies simply termed Mash Efficiency.
I have a pump circulating during the mash and I fly sparge to rinse (168ish). I also stir 2/3 times during the mash to try and prevent cold/hot spots in the mash. I'm nailing the temperature (have several probes in different spots) . About 8/10 minutes per gal to draw off to boil kettle.
When you recirculate with a pump, you have to go even slower than you'd sparge. The enzyme activity creates CO2 gas and this helps fluff up the mash bed, allowing more water through the grain particles. When you recirculate, you're stripping that gas bed out, plus you're placing all of the dust and glucans on top of the grain bed. This has the effect of creating a blanket over the grain and making the pump compact the mash. The net effect is little space to let water sparge through.
I recommend that you try a mash with just one temperature, no recirculate until vourloff. Sparge at a rate that fills your kettle in about 75 minutes (up to 90); which would be at least 10 minutes per gallon. My bet is you see a 15 point jump in mash efficiency.
Yeah there's 2 gallons of water under the false bottom plus the 1.25q per lb of grain on top. I think my false bottom plays a big part in here and i'm just not exactly sure to what degree.
Indeed it does. As soon as you start the pump and recirculate, you are diluting the mash beyond the 1.25:1. Simply, all of the water is the mash ratio. This is reinforced by the fact that you recover most of this wort during sparge. So, a 15 lb mash at 1.25:1 would need 18.75 quarts water, but then you add another 8 quarts and the ratio climbs to 1.78:1. This isn't automatically bad, but it isn't helping conversion to be that dilute. When you do that math with a 10 lb grist, you get over 2:1 and that can impact conversion. I think you'll see more efficiency if you pull the ratio back to 1:1 for 10lb grists and up to 1.1:1 for >13 lb.
I pull everything out of the pot when boil is done (my dip tube is centered). I may leave 4 cups of wort in the chiller/hoses but that's mostly trube.
I'm not sure if this means what I'm reading.... Are you saying that you pull all of the hops and trub into your fermenter? That certainly improves your brewhouse efficiency, but at the expense of your beer. Hot break in the fermenter isn't a good idea.
