I know the subject of efficiency comes up a lot, but I have a few questions. I enjoy 70% efficiency on most brews. I would like to increase that some. During the next few months, I plan on brewing 3 beers around the same gravity to work on my efficiency.
I here there are three things I can easily do to increase efficiency: crush my grains a little smaller, eliminate dead space in the mashtun, and mash out and/or sparge (I batch sparge) with hotter water. Getting a finer crush is easy. But what do they mean when they say eliminate dead space? Are they referring to the space between the grain bed and the cooler lid? Or are they talking more about reducing wort losses in your system (I loose about a quart to a quart1/2)?
Lastly, I’ve always been confused about sparge water temps. Some people just say they sparge with a certain temperature of water. So is it OK to use one single temperature sparge water for all brews? Shouldn’t I be worried about raising the grain bed to a certain temperature? And using one standard sparge water temp may not work every time?
The dead space is the areas where the grain bed doesn’t get rinsed well. If your sparge water flows down a track , say along the side of the cooler and misses flowing past all of the grain, the sugary wart from those areas will be missed and you will be throwing it out with the grains. You may have to experiment with your setup to get it right. You have to make sure that all of the grains get properly rinsed. That way you maximize the efficiency and get all of that sweet goodness into the brewkettle.
IME, it’s just not that big a deal to hit an exact temp. I almost never hit what would be called a “mashout” temp. I simply use sparge water in the 185-190 range (every time, no changes) to increase the temp of my grain to whatever before I run off the sparge. This encourages conversion to complete.
Want to say that pH is one thing to look into. I have seen graphs that show the efficiency dropping off very quickly if the pH is above 5.7. The optimum was at 5.2. The graph did not extend below 5.2, so I don’t have a clue what happens if you go below 5.2.
My two cents: If you are getting a consistent efficiency and a good product, consider leaving your system alone. My opinion is that is more important. For awhile, I got obsessed with my efficiency and started crushing pretty fine. Sure I got close to 80%, but I also created some PIA lauters! I’ve got my system dialed in to a consistent 76% every time and no lautering troubles unless I have a lot of adjuncts or something (oh that CAP suuuccckedd! >:( ) So, I have decided to leave well enough alone. My plant isn’t doing too bad. I do need to work on water chemistry a little, though. Like I said, just my two cents, if it’s worth that! 8)
Thanks everyone for the suggestions. I also noticed with my last batch that with anything less than a 1.3 quart/pound ratio with my cooler that it is nearly impossible to get consistent temps in the grain bed.
I think I’ll up my water to grist ratio a little and sparge with a little hotter water.
Another question would be batch sparging. How fast should I be draining the mashtun? I’ve heard everything from really slow to wide open. Also, when I add sparge water, how long to I let it sit in there. Some suggest 15 minutes, but other say simply stir… let settle for 5 minutes… and drain?
Since you are batch sparging, tilt that tun to drain ALL the liquid. Leaving it behind in batch sparging is like having $8-9 and putting a buck or two in the paper shredder.
I go as fast as it will go, I use a manifold so no fears, obviously a little more caution is warranted for a false bottom.
I go with 15 minutes to ensure maximum gain of malty goodness. Less is probably fine, but a couple more minutes doesn’t hurt anything. I throw my first mash water right on the burner while I’m sparging and it typically isn’t boiling by the time I am ready to add my sparge water.
Something similar that popped into my head last week when brewing the Old Jubilation which had a grain bill that required every drop I could eek out of the HLT, and I was real close to undershooting my mash temp. How far into a mash can you go and still be able to raise the temp enough not to have a wort too high in fermentables?
Example: Target mash temp is 152 . . you mash in and find out you’re @ 148 but have no hot water left in the HLT. How long do you have to get some more water ready to raise the temp before you’ve passed the window of opportunity to raise the mash temp for the desire conversion?
I’ve done that a couple of times… I just throw about 1/2gal of water in a smaller pan and boil it, I can usually boil it in less than 15min… then pour a bit at a time in the MT stir and take a temp until I get it where I want it… I’m not sure about the time threshold, but I’d have to guess anything less than a 1/2hr isn’t going to harm anything…
+1 I typically hit about 80% and was trying to lower it in effort to ensure no issues with over-sparging. Then I figured, hey, as long as I am consistent, I’ll leave it alone. I batch sparge and take lots of notes. I’d say if you hit 70% all the time…you are good to go. Brewing Classic Styles basis all their recipes on 70%.
Be careful with your water temperatures during sparging. You do want a higher water temp because it helps the wort flow better (lowers viscosity making the fluid flow easier). However, when you exceed 170 F you will begin to draw the tannin’s (comes from grain husk) out of the grain and this leads to an off taste. Several accredited sources recommend not exceeding 168 F to prevent the removal of tannin flavors from the grain.
During your mash, the ideal final temp is typically between 150-160 (depending on your grains). These temps are what promote “conversion to complete” as they are what promote certain enzymatic activity that breaks the larger starch chains into smaller chain sugars for the yeast to process. Going above these temps just promotes a lower viscosity for flow and washing.
I recommend “Brew Chem 101: The Basics of Homebrewing Chemistry” for some good information on basic chemistry that will provide guidance on pH (as another post mentioned) as well as the importance of temperature among other tidbits.
[quote]Be careful with your water temperatures during sparging. You do want a higher water temp because it helps the wort flow better (lowers viscosity making the fluid flow easier). However, when you exceed 170 F you will begin to draw the tannin’s (comes from grain husk) out of the grain and this leads to an off taste. Several accredited sources recommend not exceeding 168 F to prevent the removal of tannin flavors from the grain.
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You need temps above 170F AND pH above 6 to extract tannins from grain. And those are the conditions that have to exist in contact with the grain, not measured someplace else. If you don’t monitor your pH, then keeping your sparge water capped at 168F is a good idea. If you treat your sparge water so that it’s less than 6, it doesn’t matter what temperature you use (as far as tannins are concerned).
You boil (212F) decoctions without getting tannins. Why? Because your mash pH is probably around 5.3.
When considering increasing efficiency there are several things to consider. Assuming the use of a fully modified malt one must take into consideration the crush and by that I mean exposing all of the starch within the grain while not destroying the integrity of the husk. That can be done by milling your grain with a millgap setting between .035 and .040.
As others have already indicated keeping the mash pH (5.2 is ideal) in check is vital. I use pH strips for checking the pH. The type of grain and water chemistry will have an impact on pH. There are some great books available that discuss this in great detail.
Mash tun and grain bed geometry will effect the run off. I use a rectangular cooler and typically acheive between 75 and 80% efficiency. Round coolers also work well.
Lautering. Get the sugar out…all of it. I use a Coleman Ultimate Extreme which has a recessed pocket below the tun floor which allows for all of the wort to drain from the tun. Some say the color is also important…red vs. blue but the jury’s still out on that one. ;D