why am I missing my OG by so much??

[sternamagraph]

Hi everyone,

Iv been brewing for a while now and my first 3-4 batches i didnt pay attention to gravity readings. but my last 4 batches i have taken readings. to my supprise, i thought that my missing my est OG on the first batch at 1.047/1.083 was a fluke, but then the next i missed 1.037/1.064. those est OG were at 75% eff which i missed bad. the next i hit close at 1.64/1.065 but est at 60% eff and my last one missed 1.061/1.086. could it be that im batch sparging? the crush from my lhbs? i dont know what im doing wrong. iv done so much research and cant figure out where im going wrong. Please help if you can i would really appreciate it.

thanks,

chris.

 

[kombat]

The biggest cause of poor efficiency is the crush.

Get your LHBS to double-crush your grains, or buy your own mill and tighten up the rollers until you start getting stuck mash/sparges. Then add a couple of scoops of rice hulls to every batch and brew away.

 

[sternamagraph]

i thought about asking them to do that last time but didnt, i will def ask for that next time. thanks for your input

 

[NathPowe]

Are you adjusting your hydrometer readings for temperature? A lot of hydrometers are calibrated for 60*F. Something like this:

http://www.brewersfriend.com/hydrometer-temp/

It should say on your hydrometer what it's calibrated for. Then just take a temp reading of the sample. If you're taking readings from samples that are around mash temperature and not adjusting it would explain the issue. Obviously disregard if you're already doing this - seemed like something to mention though since the differentials you listed were so large.

Just a thought. Good luck man.

Cheers.

 

[grahamfw]

If you can, take a picture of your crush and post it to the forum. Most of these guys can spot a good crush from a mile away.

Make sure you stir the mash very well when you fill up for the second batch sparge. Also, when you take the gravity reading, take it at the start of the boil and adjust for temperature. The wort will stratify in the kettle and the boil will homogenize it. You'll get a better reading that way. (Don't burn yourself!)

 

[sternamagraph]

Thanks everyone. I did adjust for temp and also got a refractometer, the readings for the last batch are from the refractometer. I'll put my next crush on here, tho it will be ran threw twice I'll still get input. I'll start taking the reading before boil and see if that makes it any better. Thanks all, cheers

 

[Gunfighter04]

I'll add a couple more items to look for.

Water Volumes. Make sure your strike volume is around 1.2-1.5 qt/lb. also make sure your sparge volumes are correct. You should be know your loses in the process. A large amount of dead space can affect your numbers if you don't adjust grain amounts to compensate
Temps. Double, Triple check the accuracy of your Thermometers. Can't tell you how many times I've tossed what previously was an "accurate" cheap thermometer.
Boil off. If you don't know what your boil off rate is, you'll never hit your numbers. (not that you won't still have good beer)

 

[Jayhem]

+2 on the crush being extremely important. The crush should look almost like corn meal. Each grain should be broken into at least 6 pieces, if see a lot of grains in the crush that are just cracked in half or cracked but still intact then the crush is WAY too course!

When I started All Grain I had the LHBS crush my grain and got 55-60% efficiency. When I started crushing my own in a good mill I went up to 80% efficiency just like that! Now I'm closer to 85%.

 

[PHDrunk]

Yup, I would say the variability of your efficiency points to an inconsistent, poor crush from the LHBS. Double crushing will probably help (it did for me).

One thing to consider is that for a fixed pre-boil volume, you should anticipate lower efficiency with bigger beers. 1.064 is pretty standard, but above 1.070 I would expect the efficiency to drop off unless you can increase your pre-boil wort volume, and then boil down further to your typical batch size.

If your efficiency doesn't improve with a better crush, consider following Kaiser's method (here: http://www.braukaiser.com/wiki/index.php?title=Understanding_Efficiency)to separate conversion and lautering efficiencies -- if it's the crush or pH, your conversion will be ****. If it's lautering, it's something to do with your tun geometry or your process.

 

[planetscott]

Buy your own mill. The mills at the LHBS is used every day, many times a day. It gets worn out. What I crush in a year, a LHBS will do in a week. Maybe less. Never rely on the LHBS mill to do an adequate job, unless the mill is brand new.

 

[hunter_le five]

Buy your own mill. The mills at the LHBS is used every day, many times a day. It gets worn out. What I crush in a year, a LHBS will do in a week. Maybe less. Never rely on the LHBS mill to do an adequate job, unless the mill is brand new.

+1

My efficiency went WAY up after I bought my own mill, instead of relying on the HBS to mill my grain.

 

[planetscott]

This is the mill I have. I bought it right after starting all grain. I had bought a pre-crushed kit from Northern Brewer and only half of it was crushed properly.

Here is a link to the Crankandstein site:
http://www.crankandstein.net/index.php?main_page=product_info&products_id=12

 

[thisisbeer]

What kind of water are you using. I had the same issue where my efficiency varied a lot and was normally around 60%. My answer was the water. Beer that used darker malts seemed to get better efficiency than the ones with mostly 2 row. My water was to blame. I couldn't get my mash ph low enough to get good conversion on the lighter grain bills. The natural acidity of darker and caramel malts help lower the pH more. If the double crush doesn't fix things i would look at your mash ph. It made a big improvement in my efficiency.

 

[sternamagraph]

thank you to everyone that replied i cant wait to give this another shot

 

[Croyzen]

Another crush crush crush thread. Just crush it into cocaine! Post a picture of your crush so we can move on. It is true that LHBS crushes are almost always worse than your own milled crush. So it is worth posting a pic to evaluate.

Next. What is your process? Maybe there is a flaw there where you are leaving sugar behind.

If that all looks good then it's your water. Tell us about your mash pH. People group think about crush on these boards but fail to point out in groves how a majority of people in the US are brewing with highly alkaline source water. This water kills kills kills your efficiency. Now if you're brewing a dark beer this can be a good thing. So is your efficiency the same when brewing light beers AND stouts?

How do I know this? I was once a head scratcher wondering why my efficiency was so low. I had textbook crushes and my process was rock solid. When I reduced my water alkalinity my efficiency skyrocketed.

I'm not sure what's worse, mashing with uncrushed grain or using highly alkaline water for a pale ale.... Okay maybe the uncrushed grain is worse.

 

[sternamagraph]

Another crush crush crush thread. Just crush it into cocaine! Post a picture of your crush so we can move on. It is true that LHBS crushes are almost always worse than your own milled crush. So it is worth posting a pic to evaluate.

Next. What is your process? Maybe there is a flaw there where you are leaving sugar behind.

If that all looks good then it's your water. Tell us about your mash pH. People group think about crush on these boards but fail to point out in groves how a majority of people in the US are brewing with highly alkaline source water. This water kills kills kills your efficiency. Now if you're brewing a dark beer this can be a good thing. So is your efficiency the same when brewing light beers AND stouts?

How do I know this? I was once a head scratcher wondering why my efficiency was so low. I had textbook crushes and my process was rock solid. When I reduced my water alkalinity my efficiency skyrocketed.

I'm not sure what's worse, mashing with uncrushed grain or using highly alkaline water for a pale ale.... Okay maybe the uncrushed grain is worse.

hey Croyzen,
lately i have been batch sparging, because i dont have a tier setup and i have not been brewing at home. i have read all the ins and outs to this technique, so the sparge i dont think is the prob. im mashing in a 10gal home depot cooler, pre heated everytime. the ph stuff i did not know, i guess i should try a stout and see if my % goes up. ill post a crush pic this weekend.

 

[thisisbeer]

I would recommend just getting a ph meter instead of brewing a darker beer for a couple of reasons

1. Even if the water isn't the issue controlling your ph will improve your beer. The ph meter will allow you to do this. Consistency will improve from beer to beer. Your efficiency will change with lighter or darker grain bills so if you know the pH you can adjust for that.

2. If the water is the issue you will still have to purchase a ph meter to adjust it. So buying one benefits you either way.

Most people are all about the crush. My LHBS doesn't give me the best crush but with proper waste I still get high 70s to low 80s on my efficiency.

 

[BadWolfBrewing]

A bad crush is the obvious first fix. Don't need to run out and get a mill yet, just run it through the LHBS mill twice. Posting a picture of the crush here would be good, as somebody mentioned.

I'll throw something else out. When I batch sparge, which is about half, I always try to remember to do a mashout step. This means, to me, raising the temperature of the mash up to 168-170 before collecting the first runnings. I am not 100% sure why it makes a big difference, but I'd guess the sugars are more readily dissolved in warmer liquid and so it is less viscous and sticky. That is just a guess though.

Others have argued it doesn't make a difference, but when I forget this step I take a big hit in efficiency.

You could try that. There's a few ways to raise the temp. Either add some boiling water, pull off some first runnings and boil it and return it, things like that.

You could try splitting your batch sparge into two steps as well.

Finally, make sure you are really stirring the crap out of the mash once you add the sparge water.

 

[planetscott]

I'd look to share your brew days and beer with other experienced brewers as well. They might be able to identify something you are doing that is causing this. Join a home brew club. When I did, my beers got so much better from honest feedback and help.

Still, I recommend the grain mill as it gives you freedom to control the crush as well as buy grain in bulk. There are many times I wake up and decide to brew a simple recipe beer because I can.