High gravity at end of sparge and always too-low OG

Yakima 728
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funnycreature

funnycreature

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I know that "missing my OG" threads are abundant here but please help me figure out what I can do in my particular situation. I will list everything that I think needs improvement but I'm not exactly sure how I can do that.

I'm doing all-grain and mill the grain myself (I'm sure the grain crush can be improved but there must be more to my problem). I'm using a converted cooler mash tun and do batch sparging, all volumes and temps calculated with BeerSmith 2.0.

First off, I have NEVER hit my mash temperatures using the strike temps suggested by BS. This frequently results in a thinner mash because I have to add additional water (mostly boiling). My thermometer is accurate so that's not the reason. Guess I have to adjust my equipment profile for that.

Conversion is usually good after one hour as indicated by the iodine test. I do a Vorlauf until the wort is mostly clear and add it back to the mash. I then drain the wort into my brew kettle (but don't start the boil). I do batch sparging so I heat the water, dump it into the grain bed and stir it for a few minutes. I then let it sit for about 10 min so the grain bed can settle again. I repeat the Vorlauf and drain into the kettle once more.
And here's where my real problem lies: My OG is usually between 6 and 12 points low even with an efficiency adjusted to 68%. My pH at the end of the sparge is around 5.5 and the SG of the run-off is >5 Plato. My last brew started at 18.0 P pre-boil (should have been 19.9) but the larger volume (7 gal instead of 6.4) made up for this. However, the run-off, after 3.3 gal of sparging, was still 16 P! What can I do to recover the sugars in a smaller volume? Is it advisable to "recirculate" the sparge over the grains again? I have a pump and could do it but it would be more a "batch recirc" since I don't have any fly-sparging manifold.

Thanks for reading all this. :rockin: :mug:
 
I don't brew beers that are nearly as strong as you (if I'm reading this right, you were brewing a beer that was to have a preboil gravity of 1.083). You will always get lower efficiency with the higher gravity beers. There simply is not enough water to rinse all the sugars out. If I were you, I would simply adjust your efficiency settings down on BS to match what you are actually getting.

As for mash temps, are you preheating your mash tun? Fill the cooler with hot tap water and let it sit while you are bringing strike water to temp. This should help (or you could simply adjust the settings and raise the temp on your strike water).

I'm not sure what you mean by a "fly-sparging manifold". I fly sparge by simply by using my tubing (I try to wrap it into a loop so that the end is sitting about 1 inch above the water level). I regularly get better than 80% efficiency (although I am brewing beers with OGs around 1.050).
 
Thanks for the suggestions. This high-gravity beer was based on the Imperial Vanilla Porter from Denny C.

rklinck said:
I don't brew beers that are nearly as strong as you (if I'm reading this right, you were brewing a beer that was to have a preboil gravity of 1.083). You will always get lower efficiency with the higher gravity beers. There simply is not enough water to rinse all the sugars out. If I were you, I would simply adjust your efficiency settings down on BS to match what you are actually getting.
Click to expand...

According to BS my mash efficiency is 74.0% as to the predicted 74.8% so I'm almost spot on. I bet that if I took the time to confirm the boil-off rate and maybe another few equipment profile values I could nail my numbers better. Need to invest that time and propane I suppose :cross:


rklinck said:
As for mash temps, are you preheating your mash tun? Fill the cooler with hot tap water and let it sit while you are bringing strike water to temp. This should help (or you could simply adjust the settings and raise the temp on your strike water).
Click to expand...
I tried both, pre-heating the mash tun or not and adjusting the temp in BS but it's always off by 4-5 °F. I also played around with the specific heat. I guess it's time for some more empirical data collection.

rklinck said:
I'm not sure what you mean by a "fly-sparging manifold". I fly sparge by simply by using my tubing (I try to wrap it into a loop so that the end is sitting about 1 inch above the water level). I regularly get better than 80% efficiency (although I am brewing beers with OGs around 1.050).
Click to expand...
How does that work? I thought you'd have to be careful with channeling or is that more an effect of the lauter manifold (I use an SS hose)?
 
Regarding Mash temps: I suggest you read jfowler's dough in process for hitting mash temperatures (posts 3 and 4). This is how I started and it really helped me get familiar with my system, and gave me the flexibility to ensure I hit my temperature every time. I've since been able to remove some of built-in insurance(s) but, for the most part, this is how I proceed on brewday. Water:grist ratios are not that important as long as it will fit in your MLT.
https://www.homebrewtalk.com/f36/do-not-fear-all-grain-brewing-primer-247631/#post2952574

Regarding missing sugars: If you know your crush needs to be adjusted then you need to adjust your crush - aside from your missing sugars. With a proper crush, you'll get better efficiency, and the sugars that you miss will mean a little bit less. HOWEVER, this doesn't mean that crush is your problem - just that you want your crush to be appropriate for your system and process.

You mash, you vorlauf, you drain your MLT. You fill your MLT, you stir, you vorlauf again?, you drain your MLT again. You're done. At the end of this you're efficiency in not good (sounds like 60% or less).

Stirring the primary runnings/mash. You didn't mention it so I will. Stir your initial mash, prior to draining, very well. Just like you do for your second runnings (1st batch sparge). Stir, stir, stir. Stir really well for a few minutes. Drain.

After stirring, I don't wait to drain - I start draining immediately; I'm not in a rush or anything, I just don't wait. I also don't drain my runnings at breakneck speed either - I drain at a moderate/moderate-slow pace. IMHO, this allows the runnings to filter down through your grainbed at about the same speed you're collecting the running in your BK which keeps the siphon from breaking. If you drain as fast as you can but the wort can't filter through the grainbed quick enough then air will find it's way through and break your siphon. Once you break your siphon, and you don't have enough wort left in your MLT you've basically lost some portion of your highest gravity wort. You'll attempt to get it back on your batch sparge but you'll only be getting a percentage of it, the remaining portion will be left for the compost/garbage. I have found this to be very system dependent. I find that wider-than-deeper MLT (15 gallon cube coolers) are more prone to this problem than deeper-than-wider MLT (igloo-like beverage coolers).

Given a certain amount of grain; a certain amount of strike water; a certain amount of grain absorption; a certain amount of dead space; you should know approximately how much your initial runnings should be by volume. On brew day, you should ensure that you're getting the running volumes you'd expect to get. I suspect that this is where you're running into problems - not getting out the expected amount of wort for each running, which just dilutes the gravity for the next running.
 
Whoa, thanks for taking the time to write this reply!

stpug said:
Regarding Mash temps: I suggest you read jfowler's dough in process for hitting mash temperatures (posts 3 and 4). This is how I started and it really helped me get familiar with my system, and gave me the flexibility to ensure I hit my temperature every time. I've since been able to remove some of built-in insurance(s) but, for the most part, this is how I proceed on brewday. Water:grist ratios are not that important as long as it will fit in your MLT.
https://www.homebrewtalk.com/f36/do-not-fear-all-grain-brewing-primer-247631/#post2952574
Click to expand...
Thanks for the link; I actually did something similar last time but there's lots of room for improving my technique! I have a 70 qt cooler so space is not an issue.

stpug said:
Regarding missing sugars: If you know your crush needs to be adjusted then you need to adjust your crush - aside from your missing sugars. With a proper crush, you'll get better efficiency, and the sugars that you miss will mean a little bit less. HOWEVER, this doesn't mean that crush is your problem - just that you want your crush to be appropriate for your system and process.
Click to expand...

Well, I think my crush is not too bad since mash efficiency is almost perfect. I just hate the way I have to do the milling with my drill so I should say the process of crushing the grain is not the best but the results are decent.

stpug said:
You mash, you vorlauf, you drain your MLT. You fill your MLT, you stir, you vorlauf again?, you drain your MLT again. You're done. At the end of this you're efficiency in not good (sounds like 60% or less).
Click to expand...

Actually, my efficiency is usually around 65% but that's far from where I'd like to be (mainly because of all the money I put into my equipment :fro:).

stpug said:
Stirring the primary runnings/mash. You didn't mention it so I will. Stir your initial mash, prior to draining, very well. Just like you do for your second runnings (1st batch sparge). Stir, stir, stir. Stir really well for a few minutes. Drain.
Click to expand...
Now that seems counter-intuitive. I thought I need to let the grains set so they form the bed for filtering. Wouldn't the stirring and then draining cause a lot of the small sediment to potentially clog the braid?

stpug said:
After stirring, I don't wait to drain - I start draining immediately; I'm not in a rush or anything, I just don't wait. I also don't drain my runnings at breakneck speed either - I drain at a moderate/moderate-slow pace. IMHO, this allows the runnings to filter down through your grainbed at about the same speed you're collecting the running in your BK which keeps the siphon from breaking. If you drain as fast as you can but the wort can't filter through the grainbed quick enough then air will find it's way through and break your siphon. Once you break your siphon, and you don't have enough wort left in your MLT you've basically lost some portion of your highest gravity wort. You'll attempt to get it back on your batch sparge but you'll only be getting a percentage of it, the remaining portion will be left for the compost/garbage. I have found this to be very system dependent. I find that wider-than-deeper MLT (15 gallon cube coolers) are more prone to this problem than deeper-than-wider MLT (igloo-like beverage coolers).
Click to expand...

Although I do start my drain very slowly to, as you said, set the bed correctly, I increase the flow after that. I think that's what Denny Conn states on his website:
fter conversion, the sweet wort is recirculated as normal and the mashtun is completely drained as quickly as possible (NOTE:quick draining is a benefit, not a requirement, of batch sparging. I recommend you start the recirculation with the valve just cracked open, to set the grain bed correctly. After you return the vorlaufed portion to the mash tun, you can open the valve whatever amount works for your system), and an addition of sparge water is added. This is stirred into the mash, and after recirculation is once more drained as quickly as the system will allow.
Click to expand...
However, I experienced a very slow drain with this wort so maybe what you described was part of my issue. I'll investigate that for sure :mug:

stpug said:
Given a certain amount of grain; a certain amount of strike water; a certain amount of grain absorption; a certain amount of dead space; you should know approximately how much your initial runnings should be by volume. On brew day, you should ensure that you're getting the running volumes you'd expect to get. I suspect that this is where you're running into problems - not getting out the expected amount of wort for each running, which just dilutes the gravity for the next running.
Click to expand...
Another great yet simple advice! I really have to convince the wife to allow me to brew a "NIST" beer - one that's solely intended to work out the specifics of my system. Something lighter like a blonde ale that she would even like if turns out good.
Again, many thanks for your very good argumentation St. Pug! :mug:
 
funnycreature said:
How does that work? I thought you'd have to be careful with channeling or is that more an effect of the lauter manifold (I use an SS hose)?
Click to expand...

Well, you should have an inch or two of water above the grain bed. In my experience, this protects the grain bed and prevents channeling as long as you have the sparge tube close enough to the liquid.
 
funnycreature said:
According to BS my mash efficiency is 74.0% as to the predicted 74.8% so I'm almost spot on. I bet that if I took the time to confirm the boil-off rate and maybe another few equipment profile values I could nail my numbers better. Need to invest that time and propane I suppose :cross:
Click to expand...

I am a bit confused. Are you hitting your OG but missing on preboil? Or are you having to boil for a very long time to hit your OG because your preboil is low? Unfortunately, I am not in front of my computer that has BS loaded on it. But, I think that you would not be hitting this mash efficiency if you were not draining too much liquid and then boiling off more.
 
rklinck said:
I am a bit confused. Are you hitting your OG but missing on preboil? Or are you having to boil for a very long time to hit your OG because your preboil is low? Unfortunately, I am not in front of my computer that has BS loaded on it. But, I think that you would not be hitting this mash efficiency if you were not draining too much liquid and then boiling off more.
Click to expand...

I'm confused too! I just gave you the numbers that BS shows me after all the data I put in. No, I missed my gravity at both, pre-boil (but made up for most of it by an additional 0.7 gal) and before putting it in the fermenter. My volume measurements are probably not accurate at that point so maybe I still hit my 68%; all that would take is 0.4 gal more wort.
I guess this thread is supposed to help me boost my overall efficiency by finding out what steps can be improved. I apologize for the confusion and back-and-forth.
 
in my mash tun ( a cooler box) I put 6 gallons of water at 80 deg C onto 10 lb of grain, mash starts at 70 and cools to 68 over an hour. I then start straining via a copper manifold, adding another 3 gals of water at 95 deg C. I boill for 20 minutes before adding the first of the hops and boil for a further hour. I don't really know my ABV because of uncertainty of converting Brix to Sg and ABV - my last brew OG was 10 BRIX and FG was 5.1 BRIX. Beer drinks like a commercial 4% ABV.
 
funnycreature said:
Whoa, thanks for taking the time to write this reply!
Click to expand...

No problem. I just hope it's helpful in the end :eek:


funnycreature said:
Thanks for the link; I actually did something similar last time but there's lots of room for improving my technique! I have a 70 qt cooler so space is not an issue.
Click to expand...

I think this would be one of those wider-then-deeper scenarios where the draining has the potential to be much more finicky than, say, a water cooler. My buddy uses a 70qt cube cooler where the drain is a couple inches above the floor of the cooler. He has found that if draining too quickly he'll break the siphon about 2-3 inches above the floor and because of the large footprint, it equates to a gallon or more of high-sugar wort remaining. This just gets diluted on the next sparge but you'll only get a portion of those high-sugar wort back out without a lot of oversparging and HOURS of boiling to reach target batch volume.

Think if it this way. You fill your cooler half way with water and add red food coloring to make a deep red colored water (red is your sugars). Next you drain that halfway and add enough water to get back to your original water level. Now, the color of the water is still fairly red - deep pink maybe (i.e. a fair amount of sugars left). Suppose, instead of draining only halfway, you drained to only a quart or so, and refilled to the original water level. NOW, the color is now barely pink. The pink/red color are the sugars remaining from just your initial runnings, and you'll be attempting to dilute the remaining sugars into the new water on your next runnings which will be harder since sugars will already be saturating your rinse water. This is not a perfect picture but it's a way of thinking about it to get the general idea.

funnycreature said:
Well, I think my crush is not too bad since mash efficiency is almost perfect. I just hate the way I have to do the milling with my drill so I should say the process of crushing the grain is not the best but the results are decent.
Click to expand...

Beersmith has two mash efficiencies: Estimated Mash Efficiency and Measured Mash Efficiency. You'll need to look on the 'Mash' tab in the lower-right corner to see your actual measured mash efficiency.

If you're happy with your crush; everything looks broken up nicely with maybe a little flour; and it works for your system then keep it the way it is. I also use a drill and variable squeezing pressure to crush my grain. While it's far from fun or convenient, it works.

funnycreature said:
Actually, my efficiency is usually around 65% but that's far from where I'd like to be (mainly because of all the money I put into my equipment :fro:).
Click to expand...

Efficiencies are finicky numbers. Measurements must be fairly precise to get an accurate number. One-half to 1/4 gallon less into the fermenter can drop an efficiency by several percentage points on a 5 gallon batch. They're also not the holy grail of beer brewing - the beer is :D. If the beer is good and the process meets your expectations then don't stress over 5%.

funnycreature said:
Now that seems counter-intuitive. I thought I need to let the grains set so they form the bed for filtering. Wouldn't the stirring and then draining cause a lot of the small sediment to potentially clog the braid?
Click to expand...

If you're not stirring after your mash time is up then this may be where you're not being as efficient as possible PARTICULARLY with batch sparging. The point of stirring is to get the sugars that are within the grain (or stuck to / adhering to) into the liquid portion so they can drain out. There's no more harm in stirring your initial mash before draining than there is stirring your first batch sparge. If you get a stuck mash during draining, simply stir it up, vorlauf a little, and drain again. You need to be stirring your mash prior to draining. This will increase the amount of sugars you get out of your mash for sure!

The grain will set as you drain, which is why, after stirring, I don't bother to let my grains set. Having a non-compacted, "set" grainbed is much more important when fly sparging, but even then the grainbed will set itself during the drain (this is what vorlaufing is partly doing).

funnycreature said:
Although I do start my drain very slowly to, as you said, set the bed correctly, I increase the flow after that. I think that's what Denny Conn states on his website:

However, I experienced a very slow drain with this wort so maybe what you described was part of my issue. I'll investigate that for sure :mug:
Click to expand...

Again, everyone's system is different and you just need to figure out what works for your system. Play with your variables, one, two at a time, and determine the results. My problem with the "let 'er rip" method of draining is that my 1/2" drain setup will drain so quickly that the grainbed immediately compacts and I get a stuck sparge, or VERY slow sparge. If it completely gets stuck then I have to stir it up, vorlauf, and start again. If it comes to a crawl then I'll usually let it go. I would say a typical running for me is about 2.25-2.75 gallons and it takes maybe 5 minutes to get.

Denny know's his system and has been doing this a long time. He's familiar with how his equipment works and accepts whatever losses he accepts. I don't doubt for one minute that his system works the way he wants it to and the way he's described so many times. I suspect that your equipment is different though and that's where learning your system, your equipment, comes into play.

Some folks are fine with 67% efficiency while others won't be happy unless it above 80%. You just need to decide what you want out of your system and then determine how your process needs to work in order to achieve that. You can't forget to include consistency into the equation either. If you're constantly bouncing between 72-82% efficiency then it's hard to balance your hops additions not knowing what gravity your wort is going to turn out.

funnycreature said:
Another great yet simple advice! I really have to convince the wife to allow me to brew a "NIST" beer - one that's solely intended to work out the specifics of my system. Something lighter like a blonde ale that she would even like if turns out good.
Again, many thanks for your very good argumentation St. Pug! :mug:
Click to expand...

Yes. This is a good way to see if you're getting the appropriate amount of wort out of your runnings. Plus, it let's you know how much more water to add to your next sparge so you don't overdo it.

To get about 6.75 Gallons of preboil wort into my BK, I use ~8.15 gallons of water TOTAL (strike, mashout, sparge, etc) just to give you an idea.

Hope this helps.
 
stpug said:
No problem. I just hope it's helpful in the end :eek:

I think this would be one of those wider-then-deeper scenarios where the draining has the potential to be much more finicky than, say, a water cooler. My buddy uses a 70qt cube cooler where the drain is a couple inches above the floor of the cooler. He has found that if draining too quickly he'll break the siphon about 2-3 inches above the floor and because of the large footprint, it equates to a gallon or more of high-sugar wort remaining. This just gets diluted on the next sparge but you'll only get a portion of those high-sugar wort back out without a lot of oversparging and HOURS of boiling to reach target batch volume.

Think if it this way. You fill your cooler half way with water and add red food coloring to make a deep red colored water (red is your sugars). Next you drain that halfway and add enough water to get back to your original water level. Now, the color of the water is still fairly red - deep pink maybe (i.e. a fair amount of sugars left). Suppose, instead of draining only halfway, you drained to only a quart or so, and refilled to the original water level. NOW, the color is now barely pink. The pink/red color are the sugars remaining from just your initial runnings, and you'll be attempting to dilute the remaining sugars into the new water on your next runnings which will be harder since sugars will already be saturating your rinse water. This is not a perfect picture but it's a way of thinking about it to get the general idea.



Beersmith has two mash efficiencies: Estimated Mash Efficiency and Measured Mash Efficiency. You'll need to look on the 'Mash' tab in the lower-right corner to see your actual measured mash efficiency.

If you're happy with your crush; everything looks broken up nicely with maybe a little flour; and it works for your system then keep it the way it is. I also use a drill and variable squeezing pressure to crush my grain. While it's far from fun or convenient, it works.



Efficiencies are finicky numbers. Measurements must be fairly precise to get an accurate number. One-half to 1/4 gallon less into the fermenter can drop an efficiency by several percentage points on a 5 gallon batch. They're also not the holy grail of beer brewing - the beer is :D. If the beer is good and the process meets your expectations then don't stress over 5%.



If you're not stirring after your mash time is up then this may be where you're not being as efficient as possible PARTICULARLY with batch sparging. The point of stirring is to get the sugars that are within the grain (or stuck to / adhering to) into the liquid portion so they can drain out. There's no more harm in stirring your initial mash before draining than there is stirring your first batch sparge. If you get a stuck mash during draining, simply stir it up, vorlauf a little, and drain again. You need to be stirring your mash prior to draining. This will increase the amount of sugars you get out of your mash for sure!

The grain will set as you drain, which is why, after stirring, I don't bother to let my grains set. Having a non-compacted, "set" grainbed is much more important when fly sparging, but even then the grainbed will set itself during the drain (this is what vorlaufing is partly doing).



Again, everyone's system is different and you just need to figure out what works for your system. Play with your variables, one, two at a time, and determine the results. My problem with the "let 'er rip" method of draining is that my 1/2" drain setup will drain so quickly that the grainbed immediately compacts and I get a stuck sparge, or VERY slow sparge. If it completely gets stuck then I have to stir it up, vorlauf, and start again. If it comes to a crawl then I'll usually let it go. I would say a typical running for me is about 2.25-2.75 gallons and it takes maybe 5 minutes to get.

Denny know's his system and has been doing this a long time. He's familiar with how his equipment works and accepts whatever losses he accepts. I don't doubt for one minute that his system works the way he wants it to and the way he's described so many times. I suspect that your equipment is different though and that's where learning your system, your equipment, comes into play.

Some folks are fine with 67% efficiency while others won't be happy unless it above 80%. You just need to decide what you want out of your system and then determine how your process needs to work in order to achieve that. You can't forget to include consistency into the equation either. If you're constantly bouncing between 72-82% efficiency then it's hard to balance your hops additions not knowing what gravity your wort is going to turn out.

Yes. This is a good way to see if you're getting the appropriate amount of wort out of your runnings. Plus, it let's you know how much more water to add to your next sparge so you don't overdo it.

To get about 6.75 Gallons of preboil wort into my BK, I use ~8.15 gallons of water TOTAL (strike, mashout, sparge, etc) just to give you an idea.

Hope this helps.
Click to expand...

Most excellent, especially your stirring suggestion. It might just happen as you describe it - the high sugar content in the sparge run-off is simply a result from too much high-sugar wort left over from the mash. I'll work on that and try not to forget to update this thread. While I'm not too unhappy with ~68% efficiency I want to make sure I do everything possible to get the best out of my system.
EDIT: Just as a note - my cooler has a bottom drain that leaves only a few ounces of liquid behind. So once I figure out how to dissolve all the sugars there shouldn't be a significant deadspace left behind. :rockin:
 
I mash in boil kettle transfer to lauter tun ( cooler) wait ten minutes stirring once then vorlof this solved my problem i batch sparge with strike temp water
 
I might have figured out at least in part why I always have (had from now on I hope) such high gravity readings after [batch] sparging: I think I was simply too impatient when draining my first runnings! Yesterday I let the tun drain for about 10-15 minutes longer and I could still see a bit of a drizzle coming out. And guess what? My gravity readings were spot on!
As a disclaimer I also added some holes to my SS mash paddle but I doubt that this increased my efficiency :)

:mug:
 
I have noticed for myself that the strike temperature and mash temperature can really be influenced by the ambient and equipment temperature. If you are not circulating hot water into your mash tun before you add your grain and strike water you need to make sure to account for that. I always look at the different between the strike temperature calculated with and without the "Adjust temp for Equip" flag set. This flag will up your strike temp to accommodate for the heat loss into the cooler itself. You can tweak this coefficient in the equipment settings.

I have also had good luck with setting my water/grain ratio a little higher (1.5 instead of 1.25), and heating my strike water up to the higher value. I then pump in what the 1.25 g/w calculation would been, get that mashed in and stirred and then I can add additional water if my mash temp isn't what I want. I started doing this after having the same situation where I had to keep adding hot strike water just to get up to the temp I needed and having really thin mashes.

Has really help me.
 
cmoewes said:
I have noticed for myself that the strike temperature and mash temperature can really be influenced by the ambient and equipment temperature. If you are not circulating hot water into your mash tun before you add your grain and strike water you need to make sure to account for that. I always look at the different between the strike temperature calculated with and without the "Adjust temp for Equip" flag set. This flag will up your strike temp to accommodate for the heat loss into the cooler itself. You can tweak this coefficient in the equipment settings.

I have also had good luck with setting my water/grain ratio a little higher (1.5 instead of 1.25), and heating my strike water up to the higher value. I then pump in what the 1.25 g/w calculation would been, get that mashed in and stirred and then I can add additional water if my mash temp isn't what I want. I started doing this after having the same situation where I had to keep adding hot strike water just to get up to the temp I needed and having really thin mashes.

Has really help me.
Click to expand...

I usually have the strike water a few degrees higher than calculated because if I use a pump it will lose some heat there. I have also done something similar to what you suggest but less "strategical". I simply left a gallon or so of strike water in the kettle, stirred in the rest and checked the temp. If necessary I could heat up the left over to a boil and add.
Soon I'll have to be even more careful because, as you said, there is a huge impact of ambient temperature on the calculations.

:mug:
 
One more point that helped me. I noticed that I was getting a fair amount of stratification of temps in my HLT. Try stirring the Strike water and verify the temp prior to pouring it into the Mash. I've also determined with my system that I lose a degree or so if I don't use a hose to transfer the water from the HLT to the mash tun. I was using a two tier system and had the HLT above the mash tun so I'd just open the valve and let it pour in. When I did that I was losing temp due to the air contact with the water. Put a hose on it and set the end of the hose at the top of the grain bed and the temp loss didn't happen.
 
I to was haviong terrible efficiency when I started AG brewing and managed to go from %60 efficiency up to%85-90. I never used to stir my mash during the 60min and now I stir it every 15min for about 1min. I mix again before vorlauf and then drain into the brew kettle. I add my sparge water, mix it really well, let it sit 10min, stir again and drain into kettle. I repeat the same steps for my second sparge. I also stopped using my LHBS grain mill and mill it myself with a corona mill that I set the crush just enough so that a credit card fits between the plates.
 
guitarguy6 said:
I also stopped using my LHBS grain mill and mill it myself with a corona mill that I set the crush just enough so that a credit card fits between the plates.
Click to expand...

That alone is probably what raised your efficiency nearly all of your percentage.
 
stpug said:
That alone is probably what raised your efficiency nearly all of your percentage.
Click to expand...

That could be. Sadly the only way for me to test this would be to buy my grain from my LHBS and crush it there. I purchased a bunch of bulk grain and my cost per 5gal brew would almost double if I tried that. I guess I could brew the same recipe I brewed a week ago and not stir the mash. I have a refractometer and could measure the brix during the sparge and see if it's close to what I measured last time.
 
If you're hitting your preboil SG but too low on OG, try pulling your preboil sample after a few minutes of boiling. A refractometer helps in the situation.

I was in almost the same situation as you (too high preboil, spot on on OG) and have read about numerous people reading to high preboil gravities in relation to OG.

Boil for a few minutes, then pull your sample. Just stirring with a paddle will in most cases noe be enough. You'll most likely see that your efficience is a few points off if continiously getting low OG's.
 

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