All great advice so far, the only add I have is to ensure your hydrometer or refractometer are properly calibrated as well
On the batches that I mill at home I get an O G 15% higher than when my LHBS mills the grains.
I usually only have them do it for really big beers, I figure the cost of a little more grain is worth not having to mill a really large batch.
Motorize that mill. 
When I first put a motor on mine the idea was to start the grinding process and to go get a cup of coffee. Turns out mine grinds at about 10 lbs per minute. I dumped in the grain and it was gone. Now I have a 25lb hopper on that puppy.
The #1 cause of poor efficiency is poor crush. It’s not due to the batch sparging…I average about 83% batch sparging.
Don’t bother…unnecessary.
I never have, Dave. MAYBE 2%, but mostly nothing.
Hmm… it’s worked for me. The higher efficiency I’ve seen might be more due to collecting extra wort and boiling longer, though (like 105-120 minutes). You and I may both be right when you include that additional variable.
Yep, that will make a difference. When I’ve experimented with multiple sparge additions (quite a few times) I still end up with the same amount of wort as with one addition.
What is the purpose of higher temp sparge water? I also do around 170-172F.
I think of it this way. If you were to squirt some honey on a plate, what would rinse it off better? 155º water, or 170º? Its been said that hotter water may extract astringent tannins from the malt husks though. But its also been said that if your pH is in the proper range, that is not an issue. After all decoction (boiling the malt) doesn’t produce a astringent tannin problem. So, I tend to sparge quite hot, like about 190F sparge water, and have found no astringency issues. I can’t say that it hugely increases my efficiency, but it does get my preboil wort closer to a boil. So I do it because I can, with no negative effect, and a little saving of time waiting for a boil.
Regarding the original post, assuming the grain was crushed and had sufficient diastatic power, (all we know is it was 15 pounds of grain, 3 of it was flaked oats. We assume the other 12 was base malt, but we’ve seen folks use nothing but crystal…) assuming all else is well, I would wonder what the pH of the mash was.
Has anyone addressed “efficiency” yet? I assume the OP is talking brew house efficiency, since most people only measure OG of the final wort going into the fermenter. I get right around 72% brew house, or gravity of wort in the fermenter. But my mash efficiency is always right there with Kai Troester’s chart. If I mash 1.5 qts per pound I am always right around 1.080. According to my math thats about 85% in the mash tun. I assume I lose a little efficiency in my sparge/lautering, and the rest is equipment hop and trub loss, because im basing my brew house efficiency on the 6 gallons in the fermenter, not the wort in my pump, tubing, grain absorption, hop absorption, and the remaining couple quarts in the bottom of my boil kettel. I’ll bet my 75% is more like 82-84% if I measured the full deal.
So, something tells me his low efficiency is probably a combo of math issues and/or unknown pH which is probably too high or possibly too low.
Welcome to batch sparging! I’ll give you my stock advice because it hasn’t quite been stated in this thread yet:
Rather than chase down any particular efficiency number by tweaking this, that, and the other thing (often all at the same time) chase down consistent efficiency regardless of how high or low it is. If you do that, then you can predict what you’ll get for your OG. If you don’t then you’ll always be tweaking this or that and always need to adjust either your final volume or bump up your OG with extract additions. I would brew several batches within a close range of lower gravities (say 1040 to 1065) and keep everything constant to see if get similar results each time. Then you can tweak a parameter at a time to change things if you want, and know that your process is predictable.
Makes perfect sense to me. Thank you!
Hot liquor-to-grist ratio was not the problem. I routinely mash at 1.25:1, and I obtain between 29 and 31 points per pound per gallon based on the grist composition (between 81% and 86% treating the entire grist as base malt for the calculation). My usual total mash and sparge volume is around 3 quarts of hot liquor per pound, which means that bigger beers have longer boil times. I also do not crush my malt super fine (my mill is gapped at 1mm), nor do I perform a super slow sparge.
The OP’s low efficiency was due to lack of experience coupled with a huge grain bill. It will get better with experience. My extraction rate for my first all-grain batch was 24 points per pound per gallon, and it was not a big beer.
Well, Jim, that seems to make sense…except that reality says it doesn’t! Keep in mind that the sugar is already in solution. Unless you’re already at the limit of sugar solubility in the water, hotter water won’t matter. And in a mash, you’re nowhere near that limit. There is no solid sugar to be dissolved during the sparge, since the sugar is all in solution when it is created. The solubility of maltose in water at mash temps is about 66.7 % by weight (2 lb of maltose will dissolve in 1 lb of water, (ref:http://chestofbooks.com/food/science...er-gillis.html), and this is equivalent to an SG in excess of 1.300.
But like you, I sparge with hot water…like 185-195 hot. Because the pH is fine, there is no tannin extraction. And the extra heat gets me the last little bit of conversiuon I might otherwise miss.
I totally agree with this. To put it another way, the viscosity of wort is nowhere near that of honey. The consistency of wort in the mash has more similarity to water than it does to honey, or to molasses, or liquid malt extract, etc. It’s already very well dissolved in a lot of water. So, if you heat it up, it’s not really helping make it more fluid or “more dissolved” (really no such thing); it’s already plenty fluid and 100% dissolved.
The only real reason, then, for anyone to heat up the sparge water is to save some time later in how much time it takes to bring all the wort to a boil. By adding 190 F water, or even boiling water at 212 F(!), you’re basically preheating the wort, with no detrimental effects. Hell… I think I’ll start using boiling water from now on. And why not! There’s no drawbacks at all, as long as mash pH is reasonable in the low 5’s, which mine is.
Yep, we talked me into it. From now on, I shall use boiling water for all my sparges. I’m dead serious.
Yeah, I read that in several places too (probably older brewing texts) and I never understood how viscosity came into play. I understand that from a physics perspective there is a measurable difference in the viscosity of water at different temperatures. However, in the ream of what we’re doing in the mash it seems mostly irrelevant unless I’m missing something. Maybe this is more relevant in large scale mash tuns where gravity and short distances aren’t helping as much?
After reading about pH being far more relevant to tannin extraction I started adding more acid with certain grain bills and eliminated a harshness I was getting in some of my beers. Since then, I’ve increased my sparge water temp to ~200F and none of the harshness came back. I didn’t really see much change in efficiency (maybe minor, but within the margin of error). Just like others said, I do it because it gets me that much closer to boiling by the time it hits the kettle.
I’ve never done a side by side comparison between sparging with 150 of sparging with 190 to see if one rinses more sugar than the other, so I’ll take your word for it. Like I said, I’ve not seen much change in efficiency by sparging hotter. Since I’m not draining every drop from the grain bed, or tubing, or pump, or the bottom of my boil kettel, I clearly dont care about squeezing out another 2 or 3% efficiency. But I know my pH is fine and that means I wont extract tannins, so why not get closer to boil temp? That is more my point than the honey analogy. If the analogy came off like the whole point of my post, I apologize.
I sparge hot partly because (as others said) it speeds up the process of getting the wort to a boil. No pH issues, so no issues there. Even though I don’t do a true mashout I still like the idea of raising the grain bed temp to have some semblance of locking in the mash profile. Not resting @ mashout for the prescribed time probably does nothing to lock it in, but at least it speeds up the time to boil worst case.
Well, I spent a few minutes reading Kai’s wiki, and all I can say is that the KISS principle is nowhere to be found. Part of the problem is that Kai works with the metric system, which is not as straight forward as working with English measurements when brewing.
For those who are open to new ideas, a quick and dirty way to determine extraction efficiency is to take the gravity of the cast-out wort, convert it to points, multiply that value by the total volume of the cast-out wort in gallons, divide by the weight of the grist in pounds, and then divide by 36.
sg_to_points = (gravity - 1.0) * 1,000
The above conversion can be accomplished in one’s head by making the number to the right of the decimal point in an S.G. reading an integer (i.e., whole number)
Example
1.065 = 65 gravity points
extraction_rate_in_points_per_pound_per_gallon = gravity_points * cast_out_wort_volume_in_gallons / grist_weight_in_pounds
quick_and_dirty_extraction_efficiency = extraction_rate_in_points_per_pound_per_gallon / 36
The value 36 is derived by multiplying the gravity points in a pound of pure sugar (45) by 0.8 (a dry basis, fine grind value of 80%). Kai states that the 80% value is more like 77% in practice due to moisture pickup; therefore, we could adjust the value 36 down to 34.65 (35). However, the value 36 is good enough in practice. The reason why we can treat the mash as being 100% base malt is because the base malt dominates the total gravity points to an extent where it swamps out the lower yielding malts.
Remember, all efficiency percentages are merely approximations due the fact that we do not know the actual maximum yield for any given malt, which it why I stop at points per pound per gallon. I do not care what my efficiency numbers look like. I want to know how much extract I can yield from a given amount of malt. Points per pound per gallon (PPG) gives me a number that I can scale up or down.
My average extraction rate in PPG is 30, that is, the extract from one pound of grain in a one gallon solution has an S.G. of 1.030. All I need to do to determine the amount of grain that I need for a batch is to divide the target gravity in points by 30 and then multiply that value by the batch volume in gallons.
target_gravity = 1.056
batch_volume = 6 gallons
grist_weight_in_pounds = 56 / 30 * 6 = 11.2 pounds of grist
This system makes formulating a recipe brain dead simple.
For example, SNPA has an S.G. of approximately 1.053. Using the PPG value above, I need to use 53 / 30 * 6 = 10.6 pounds of malt.
Let’s assume that SNPA is 97% base malt, 3% British C60.
base_malt = 10.6 * 0.97 = 10.282
c60 = 10.6 * 0.03 = 0.318
In practice, I would round 10.282 down to 10.25 and 0.318 up to 0.375 to make weighing out the malt easier.
55% is too low for mash efficiency. What was the volume of wort you collected at 1.060 SG? The first three areas of focus are:
- measurement precision and accuracy when taking volumes and SG readings.
- grain crush. The kernels should be broken ideally with limited/minimal hull shredding.
- mash ph. Did you test your mash ph? Did you do an iodine test for conversion?