The gentleman who offered his advice reports 80% efficiencies using the same grain mill and municipal tap water that I am using.
Clearly I am doing something wrong.....It could be my technique, could be my math, or it could be how I am using the recipe builder. Any thoughts or insights would be greatly appreciated.
G-Dubs
This is going to be long, because there are too many variables for it to be short (plus I talk too much)...
I too consistently get in the 80% vicinity. I have friends that do full-volume brewing, some with or without a bag (all-in-one electric 'basket' systems) and they hit in the 68–75% range regularly. (each one is consistent, but their systems vary compared to each other) The difference? They are all on electric with a basket, only one uses a bag too, and he squeezes the snot out of it. (he's the 75% guy) I'm on propane with a stand-off bottom and I also squeeze the hell out of my bag. The resulting grain is damp, but quite pasty. If I let the bag continue to drip in a bucket, I end up with less than an ounce after 20-30 minutes. (I did it as a test once to see what gravity would still extract)
But let's take a step back. Did you read the Brewer's Friend explanation on Efficiency? Do you understand what it is you are calculating?
There are steps in the process that serve as 'filters' which hold back or prevent sugars that are in the malt from making it into the fermenter. (what 'efficiency' means - what % of sugars made it how far)
Your first filter is the malt itself. It varies. BF Recipe Builder uses pre-defined numbers based on general 'average' specs that the maltsters provide. I don't know how often BF updates this, but it can be different from crop to crop, and lot to lot. (each kilning batch can be different) The variance isn't huge usually, but at our scales, small changes early reflect as larger numbers as that efficiency equation extends through the process. Personally, I find BF's estimates are a bit low. I routinely get *over 100% conversion efficiency. (the Mash Complete log) While it isn't critical, you could determine your own real expected PPG yourself by doing a Congress Mash for each sack/batch, but that's lots of work. I did this once for a malt that wasn't in the system, but there are easier first steps...
Crush: I've experimented down to 0.024˝. (with Wheat!) That works, but absolutely requires stirring if you are recirculating. Your bag *will* clog and you can end up with more wort filling the bag and leaving dry space or a vacuum underneath. We got in the high 80% range on that one. I now regularly crush to 0.030˝ in 2 passes: first at 0.035˝, then at my target. (a necessity since it is nearly impossible to get the mill rolling at that low gap from whole grain) Some folks double-crush at the same gap. I use it as an opportunity to hit a lower gap. I use a feeler gauge for gapping—≈$5 at Harbor Freight or Northern Tools. A finer crush and more water assist with extraction, but you can get reasonable results at larger crushes with thinner mashes. (see:
https://braukaiser.com/wiki/index.php?title=CrushEval)
Making sure you hit close to 100% at the Mash Complete step is your first control. (ensuring your mash really is complete) As noted by others, do an Iodine test. My personal experience is I usually have to mash for 90 minutes. I recirculate and I stir every 10 minutes. (I can heat the mash to maintain temp, so heat loss isn't a big deal for me) I mash until I'm done, never by time. I also started rinsing my grains *after* raising the bag, not with more water - but with wort via my recirculation. I consistently buy another 0.005sg by doing so. This is during my Mash Out step at 168℉ which doubles as a weak Vorlauf, something I want to improve on. The higher temps help you rinse more sugars off the surface of the grain. I'll also add that pH control is critical to conversion. If you aren't measuring it and adjusting as needed, make that your next upgrade. Your brews will improve considerably. My best tasting beers and most on-target numbers are for brews where I hit 5.2, (at room temp measurement) yes, even for dark beers. If you don't have one, get a refractometer and regularly (each time you stir is good) check your gravity progress, and verify you are holding temp - write it down! That record will help guide you to decide when to start doing iodine tests then proceed to mash-out, rinse & squeeze.
The second filter/bottleneck is Lautering. For us, that's the bag. My bag (The Brew Bag) has handles and I suspend it overhead from an eyebolt with a ladder. I twist it till very tight then squeeze what little is left. (a pipe or mash paddle wedged in the ladder is very helpful here if you brew alone to keep the pulley rope from spinning against you) The drier you get the grain, the more wort (and sugars) stay in the kettle. Loss here varies by grain bill but I seem to average about 0.075gal/# or 0.3qt/#. (≈10oz/#)
Now you hit the first really large and harder to control variable - boil off. Advice on this one is all over the map. Mine would be to maintain a 'level 4' Vigorous boil (not violent level 5 or volcanic level 6) and calculate the loss for your system over several batches. (see:
) Put the average in your BF equipment profile and work to get a consistent feel to boil strength. I average 1.7gal/hr and I boil for 90 minutes. (yes, yes, I know even 60 isn't strictly necessary, but my beers are night-and-day between 60 & 90 minute boils - regardless of style.) Of course, you can go with short boils or even just pasteurization to reduce loss here. You can 'simmer' the beer for 60 minutes if you like. This is all up to you. (see:
https://brulosophy.com/?s=boil+length)
The last variable is knockout. If you dump the entire kettle, then loss is zero. If you use fining agents, whirlpool and stand in order to pile trub and rack off only the cleanest wort, your losses will be higher. This is a personal preference, but be aware if you are not consistent in how much kettle loss you have each batch, your efficiency numbers will be all over the map. (see:
https://brulosophy.com/?s=kettle+trub)
And that brings me to my conclusion: measuring volumes at our scales requires precision if you are concerned about small percentage changes in efficiency. (as is accuracy in measuring SG and being meticulous about temp corrections) Variations in volume less than a quart can greatly influence your final numbers. If you have a sightglass, verify it is calibrated, add markings for quarts at least if you don't have them. Learn if the volume value is at, above, or below the line. When you verify the calibration and you are using an electric all-in-one system, take note of what equipment is installed. We found the Brew Easy Compact for example was calibrated entirely empty, but with probe, element, pickup tube et cetera, the difference was nearly a quart! If you don't have a sight glass, use a tape measure to get the depth of the wort, then the diameter of the kettle. Calculate the volume as: (πr^2*depth)÷231=gallons. The more precise the tape measure reading, the more accurate the volume measurement. Measure *actual* kettle loss after racking to fermenter. If you have plumbing losses, measure those too. (½˝ID silicone hose holds ≈ 1.31 ounces/linear foot) Don't guesstimate - measure. For *every* volume measurement - take the temp of the lost wort. BF log entries can auto-calibrate the volume to room temp.
My last advice: all of this is fun. Relax, don't worry, and have a home brew!
