OG is always 10 points off!!!

[upheaval]

I'm new to AG and fairly new to taking readings seriously...
The last 3 brews I've done my OG has been off my 10 points (lower than expected). At first I figured my hydrometer was faulty but using my other hydrometer and getting the same reading led me to believe I'm obviously doing something wrong.

I don't even know where to begin. My temps are always either spot on or within 1 degree. The only thing I can think of is the software I use takes into account for more liquid loss than what's actually taking place (about 1-.5 gallons). Could this be the problem?

I'm sure this has been brought up loads, but Im at work and find it quick to type this up than search through pages and pages.

Thanks

 

[WayFrae]

You could just adjust your efficiency on your software. What is it set to?

 

[bknifefight]

Post a pic of your crush. I bet it's that.

 

[upheaval]

@WayFrae Efficiency is set to 70%

@bknifefight Crush? Lol sorry what's that?

 

[peterj]

Yeah if your software is predicting more boil off than what you're getting, that is definitely a reason you are getting a lower OG. You should change the setting with your software to match what you actually boil off.

And like WayFrae said you should adjust your efficiency on your software to match what you are getting. The brewing software should be used as a tool to help you predict how your individual beer will turn out on your individual brewing system. There is no concrete efficiency number that you have to get or you're doing it wrong. As long as you can consistently predict what your OG will be, then you can make your recipes accordingly.

If you want to improve your efficiency though, the first place I would look is your crush like bknifefight said.

 

[LLBeanJ]

The only thing I can think of is the software I use takes into account for more liquid loss than what's actually taking place (about 1-.5 gallons). Could this be the problem?

Yes, this could definitely be the problem. Since you're fairly new to AG brewing, I'd be taking gravity samples and volume measurements both pre- and post-boil in order to fully understand the variables, such as boil-off rate and efficiency, in your system. Once you have the variables nailed down and setup correctly in your software, you should start to see less variation between brews and more predictable results.

 

[WayFrae]

Oh, yeah you don't really want to get less than 70% (For cost reasons but you could get 25% efficiency and still make good beer as long as you used enough grains. I was thinking maybe you had it set to 80-85%) so it probably is the crush. Crush is how fine the grains are milled. If your crush is too coarse it will effect your efficiency. If you have them milled at the LHBS ask them to run it through twice and see if that helps your efficiency.

EDIT: For the record. I am new to AG also.

 

[fixitoscar]

The only thing I can think of is the software I use takes into account for more liquid loss than what's actually taking place (about 1-.5 gallons). Could this be the problem?
Thanks

usually is one of 2 things.
first thing to look at is your post boil volume. If you have more wort, post boil than predicted you will have a lower og due to dilution. The other way around if you boiled off too much you would have a higher OG because its more concentrated.
second thing would be what others are saying. Your efficiency. the thing that has the most effect on your efficiency is your crush on your grain. How thinly
milled it is. After that would be mash tun design.

 

[bknifefight]

@WayFrae Efficiency is set to 70%

@bknifefight Crush? Lol sorry what's that?

Your grain is crushed, isn't it? What I suspect is that it's probably not crushed fine enough.

 

[BierMuncher]

Just because you set an efficiency in your brewing software, does not mean you are going to achieve that efficiency. Your brew process and setup determine the efficiency, then you use that efficiency to drive your recipes. Brew a few batches, go back to your brewing software and tweak the efficiency until it reads the OG you actually hit. So if your softwrare told you that at 70% efficiency you should hit an OG of 1.050, and you hit 1.040, chances are your efficiency is more likely in the low 60’s and that is where you need to set your softare to attain the targeted OG.

Once you determine what your predictable efficiency is through a few batches…THEN you can start to work through the other components (grain crush, boil off rate, etc) to actually move the needle on your real efficiency.

 

[mclamb6]

Post a pic of your crush. I bet it's that.

Seconded. On my system, I've got boil off fairly well dialed in. Unless I'm really pushing the grain capacity of my mash tun, the crush really dictates how close I am to anticipated OG.

 

[peterj]

How much do you boil off and how much does your software predict for your boil off? If you end up with half a gallon more than your software predicts then that would be about 5 points right there.

 

[DrunkleJon]

Grain Crush - If you have grains that have not had their outer husks broken you will have trouble extracting all of the sugars. This can be an issue with LHBS and precrushed kits.
Efficiency - everybodies system is different, once you figure out consistently how your system works, you can plug your efficiency %age into BeerSmith or whatever software you use to up your grain amounts to compensate.
Boiloff - Works with efficiency. If you end up with 6 gallons instead of the estimated 5 you will have a lower OG, same works if you boil off down to 4 Gallons when expecting 5 giving you a higher OG.

These are the common causes.

The only thing I can think of is the software I use takes into account for more liquid loss than what's actually taking place (about 1-.5 gallons). Could this be the problem?

Exactly, that is point 3 there. If you always end up with a spare half to whole gallon, reduce your sparge by that much and see if it fixes it or boil a little longer until you reach your FG/volume.

 

[helibrewer]

The only way to nail this down is by analyzing each of your conversion steps. Us the following chart to assess your mash conversion. Enter the chart at your grist ratio. Your SG should be well over 90% of the chart value, if it's not, you have conversion issues (temp, crush, time, pH, etc.)

If your conversion is good then you need to assess your lautering. Use the following chart by adding water to your drained MLT to one of the ratios indicated (this can be cold tap water). Take an SG reading. Find the SG reading on the chart that matches your water ratio. This number is the percentage of fermentables left behind. Subtract this value from the above percentage to get your overall conversion percentage, it should be in the 90+% range. This way you know where in your process you need to focus:

 

[MindenMan]

For a long time, I was struggling to hit the pre known O.G. of my wort. I followed the "rules" exactly, you know, (x) gallons of sparge for (x) pounds of grain, will produce (x) O.G.. What I found out was there was a boatload of sugar still left in the grain. I was getting a gallon+ of 1.030 wort still left in the sparge, and when added to my boil, after reducing down, my O.G. increased. Your crush could very well be the problem, and/or both.

 

[upheaval]

Thanks for all the replies. Love this forum!!! A buddy of mine gave me a spreadsheet he had and after putting in my numbers I did end up with 1.19 gallons of water then I actually needed. So I'm going to start there with my brew on Sunday and see what I came up with. If that doesnt do the trick I'll be back here to break down these helpful responses.

Thanks again all. Slowly but surely these boards will turn me into a knowledgeable brewer.

 

[upheaval]

UPDATE: Brewed yesterday using my new spreadsheet and was able to hit my #'s spot on! I appreciate everyone's input and help.

 

[Darken99]

Are you testing starch conversion?
Are you testing temperature of your mash after water is added and mixed in?
Are you mixing your mash up really well after you add water?
Are you batch sparging and adding all of your water for your sparge at the same time and draining off as fast as you can?
Are you multiple batch sparging and draining as fast as you can?
Are you using increased temperature of your batch sparge?

 

[jef179]

I have been brewing for a while and my system was dialed in, then I started getting low efficiency ... I couldn't figure it out until I tested my thermometer. It was 12 degrees F high, therefore I was mashing at 140- 144. If your crush is good and your water ratio is good, try double checking the temp. Of course it makes a huge difference.


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