original gravity way lower than expected

so I brewed a recipe I had written today for an imperial ipa recipe...according to my calculations and hopville assuming 70% efficiency it came out to 1.100 or so original gravity. When we chilled the wort and got it to reading temp, it came out 1.050. The grain bill is as follows:

17lbs row 2 pale malt
1 lb Crystal 40L malt
8 ozvictory malt
8 oz Wheat Malt
1lb 8oz corn sugar

Anyone have any idea what may have caused this...if it's something we did wrong or maybe just read incorrectly...The wort appeared to be packed with sugar through the entirety of the boil. It is pretty packed with hops at about 6 oz too...could that potentially affect it?

Hops wouldn't impact OG. What efficiency do you normally achieve?

Crush is the most likely cause... are your thermometers calibrated?

Sounds like an incorrect reading...that would mean only 35% efficiency.....cant be right.

Did you stir wort before taking sample.......you may have pulled the lower gravity liquid off the top and got lo reading.

I did this once on my first all grain.....pulled sample for OG reading and it was WAY lo.....posted on here.....and someone pointed this out...i stirred...took another sample and was right on.

Its called stratification....lower gravity liquid settles on top cause lighter.....u need to mix it up a little to get a homogenous liquid

Its a possibility.....

Was your volume at the end correct? If it was, I'd say you read it wrong, didn't mix it up well, or perhaps have a thermometer that is off, and a hydro that is off..

That grain bill is large enough that you should have gotten higher.

What was the pre boil OG? What about the 1st runnings... what was the gravity of that coming out?

This was our first all grain brew, however we know what we're doing. The wort appeared to be packed full of sugars. Original gravity calculation was 1.102. Since this was the first time brewing this recipe, we were unsure of several factors such as how much water the grain would take on so we fell a little short of the estimated final volume and did fill. We're thinking maybe that late addition water could have affected the reading. Also, I took a sample from the top and tested that. Perhaps it was a problem with the wort from the top.

I'd lean in the direction of multiple of factors... bad volumes (my calculations come out to .13 gallons/lb of grain absorbed), poor crush, and if you added a good amount of water to compensate for the final volume. As the other person said, measurement was wrong due to unmixed wort/water.

If you don't use software like beersmith (I don't) then mash calculators are your friend.

citylights said:

This was our first all grain brew, however we know what we're doing. The wort appeared to be packed full of sugars. Original gravity calculation was 1.102. Since this was the first time brewing this recipe, we were unsure of several factors such as how much water the grain would take on so we fell a little short of the estimated final volume and did fill. We're thinking maybe that late addition water could have affected the reading. Also, I took a sample from the top and tested that. Perhaps it was a problem with the wort from the top.

Click to expand...

If by this statement you meant that you used top off water in the fermenter to get your proper amount then you probably had imcomplete mixing and were much closer to you intended OG than what you read.

Get yourself a copy of Beersmith.....go to their sight and download it...there is a free 21 day trial. It will help you with your volumes, temps, etc.....

citylights said:

The wort appeared to be packed full of sugars.

Click to expand...

Was it a single infusion? What was your mash temperatures and times? Did you sparge? What type of lauter tun?

citylights said:

This was our first all grain brew, however we know what we're doing. The wort appeared to be packed full of sugars. Original gravity calculation was 1.102. Since this was the first time brewing this recipe, we were unsure of several factors such as how much water the grain would take on so we fell a little short of the estimated final volume and did fill. We're thinking maybe that late addition water could have affected the reading. Also, I took a sample from the top and tested that. Perhaps it was a problem with the wort from the top.

Click to expand...

I don't know how you figure it appeared to be packed with sugars, but anyways..

So you came up short on volume, that should have given you a higher OG. But then you topped up with water.. did you do it at the end of the boil? You'll obviously want to not do that all the time, so figure out the calculation to get your volume.

If you added water, you probably didn't mix it well. Stratification will occur with the higher gravity sinking to the bottom. Chance are, you got the top end with the water. It's pretty hard to get it all mixed in really well to get a reading.

Mash volume and grain absorption would be useful to know here as well.

If the mash volume was 7.6 gallons, and the grain absorption was 0.2 gallons per pound that would be 3.8 gallons absorbed. If the OP did not sparge that would explain the problem.

If the mash volume was 5 gallons with a single batch sparge I bet the result would also be about where the OP ended up.

I figured it was packed w sugars because the entire boil was basically a hot break. We did top off w water so I figure that is the problem. We did mash and did one batch sparge. Being as it was our first time I was unsure exactly what to expect w grab absorption...I had predicted 2.5 gsll

WoodlandBrew said:

Mash volume and grain absorption would be useful to know here as well.

If the mash volume was 7.6 gallons, and the grain absorption was 0.2 gallons per pound that would be 3.8 gallons absorbed. If the OP did not sparge that would explain the problem.

If the mash volume was 5 gallons with a single batch sparge I bet the result would also be about where the OP ended up.

Click to expand...

If he didn't sparge, he'd have a higher gravity, due to the lower volume. Opposite of his problem. He added water to get his volume, and probably added too much, and didn't mix top up water well enough for taking a hydro sample..

Just my guess.

Yes, the wort would have high gravity in the boil, but after topping off it would be low, which is what he reported.

citylights said:

I figured it was packed w sugars because the entire boil was basically a hot break. We did top off w water so I figure that is the problem. We did mash and did one batch sparge. Being as it was our first time I was unsure exactly what to expect w grab absorption...I had predicted 2.5 gsll

Click to expand...

It is a lot harder to mix water and high gravity wort together than many people give credit. Without a concerted effort to mix the wort/water, I would expect that the gravity reading you got was falsely low.

No way to know now unless you know someone with a SCABA or maybe one of those new lab test kits out there.

Do another brew and see if you get the same result.

Best advice I can add is take more gravity readings. Minimum take a preboil gravity. I batch sparge and take a gravity reading on each set of runnings. With this size grain bill I likely would have had 2 sparge infusions, so I would have taken readings on the first runnings, 2nd, and 3rd, then a preboil and finally an o.g. After cooling.

Thanks everyone. You pretty much confirmed what I thought had happened...just wanted some other opinions....it's now in the fermenter rapidly fermenting

citylights said:

Thanks everyone. You pretty much confirmed what I thought had happened...just wanted some other opinions....it's now in the fermenter rapidly fermenting

Click to expand...

At what temperature? You'll want to keep this one near the low end of the yeast's preferred range as it has a lot of sugars and the yeast tend to get too excited with all that food and like to make some byproducts that aren't particularly beneficial to the flavor of your beer. Once the fermentation settles down it will be OK to let it get warmer.:rockin:

I'm sure others here have targeted your issues more than I would, but I can't stress enough a good crush. I have a local HBS that even brews their own beers in house, for sampling, so I figured their crusher would be fine to use. I switched to all grain 3 batches ago and the first two were about 10 points lower than they should have been on OG post boil, and about 15 points low on pre-boil. I changed things up on my end on the second brew, made sure to hit water exact, figured my boil off rate exactly. The last thing was the crush. I ddin't pay much attention originally, because as I said, they brew in house and use that mill, so why would it be off. On closer inspection though, over half the grain was still completely intact grain. I sprung for my own mill before this last batch and went from roughly 56% efficiency up to 74% by using my own crusher.

Being new to the all-grain business, I'm sure that the lowe effieciency was in part to my mistakes and getting a system down, but a little experience, combined with the look of the grain after my home crush compared to the HBS, was night and day.

I would tell the owner of the lhbs about the crush issue and that there were uncrushed grains. There is a lot of conspiracy theory that LHBS guys set their mills to crush poorly on purpose. I don't think that's true because there is sooo much on the Internet about grain crush that the most avid brewers (their largest volume potential customers) are going to know that it's not right and choose to shop elsewhere even paying less to buy on the Internet. There has been no difference in my efficiency between my LHBS's mill and my own except a small drop that I attribute to the LHBS measuring grains a little heavy handed. I have tried setting my mill at a variety of widths going as low at .035 and the only difference when I got that low was a slower sparge. The biggest impact that I have been able to make on my efficiency has been to use an adequate volume of sparge water.

Edit: my efficiency is typically 80% for beers under 5% abv, 75% for 5-6.5% beers and 70% for higher gravity beers. I estimate everything at 75% for simplicity

+1 to adequate sparge water. Crush is very important but sparge water can easily be over looked. If you pack your mash tun full and don't leave enough room for sparge water not only will you have low efficiency, but you can even end up with a lower OG when using more grain! For my small batch system I actually have a higher OG with 7 pounds of grain and 1 sparge than I do with 11 pounds!

Interesting premise, the idea of stratification. If you drain from a keggle, do you think the sample at the end would be lower gravity because the ball valve pulls from the bottom? I brewed an ipa this weekend and in the end missed target gravity by 9 points. There are a number of other possible mistakes, but this is an interesting thought.

I have seen stratification from syrups that aren't properly mixed such as LME and corn syrup, but once it is dissolved is stratification really an issue? Does any one have data showing this, or is it theoretical? I thought that particles will sink (suspensions) but dissolved solids (solutions) will stay pretty homogeneous.

WoodlandBrew said:

I have seen stratification from syrups that aren't properly mixed such as LME and corn syrup, but once it is dissolved is stratification really an issue? Does any one have data showing this, or is it theoretical? I thought that particles will sink (suspensions) but dissolved solids (solutions) will stay pretty homogeneous.

Click to expand...

Yes; Personal experience. The higher the gravity brew all grain using fly sparge, in my set up, the lightest gravity run-off goes on top. I have to stir and sample 3-4 times before my gravity stabilizes and it gets higher each Time it's read.

Brewskii said:

Yes; Personal experience. The higher the gravity brew all grain using fly sparge, in my set up, the lightest gravity run-off goes on top. I have to stir and sample 3-4 times before my gravity stabilizes and it gets higher each Time it's read.

Click to expand...

I could see an issue in the mash. but I wouldn't call that a solution. When fly sparing it does take some time for the water to trickle through the grain bed. I thought the OP had a problem when taking a sample from the fermentaion vessels.

WoodlandBrew said:

I could see an issue in the mash. but I wouldn't call that a solution. When fly sparing it does take some time for the water to trickle through the grain bed. I thought the OP had a problem when taking a sample from the fermentaion vessels.

Click to expand...

Yes, he did. He said he topped the fermentor to hit a target volume with water. My thought is that the OP's innitial gravity reading was not representative of the mean of the gravity of the wort plus the added water due to it not being homogenous at the time he sampled it. Furthermore, with the gravity of water being 1.000, if he obtained the sample from the top, the OG number he got would have been low, which is what he said he saw.
It's the same principle if you bottle and don't stir the priming sugar solution into the full bucket. There are those that do this, but, at some point it usually ends in inconsistent carbing for the same reason I mentioned above.

It is my experience that it actually takes a conscious effort to get the high gravity and low gravity solutions to mix. You can't just pour it in and expect them to mix - same as in fly sparge when trying to get an accurate kettle full gravity.

The best example I can think of showing stratification of solutions is a trying to pour a back and tan... without a spoon. Even with a spoon it is difficult achive something other than just brown.

WoodlandBrew said:

The best example I can think of showing stratification of solutions is a trying to pour a back and tan... without a spoon. Even with a spoon it is difficult achive something other than just brown.

Click to expand...

The difference in gravity of two finished beers is exponentially closer than that of unfermented wort and water.
The example I think that closer fits is that of grenadine in a tequila sunrise....

In fact; let me test that out

Btw... I'm really not saying your wrong; you defiantly have a good point - I'm just trying to explain my POV. My example is a little more exaggerated in the opposite direction than yours. My stratification issues have gotten me before. Your process is different and therefore your experiance will be different.

WoodlandBrew said:

The best example I can think of showing stratification of solutions is a trying to pour a back and tan... without a spoon. Even with a spoon it is difficult achive something other than just brown.

Click to expand...

Not really the best example, but you are somewhat correct. Some mixing will occur.

However; water and the finished wort, aren't anywhere near the same specific gravity. The best example that you can see if simple.

Take a glass, fill it with water 3/4 of the way full. Top it off with maple syrup. Both are thin.

Pour the syrup in as rough as you'd like. Watch the bottom of the glass.
It'll collect most of the heavy gravity syrup. The water will taste sweet, but mix it up, and taste it again... it'll be sweeter.

FATC1TY said:

Not really the best example, but you are somewhat correct. Some mixing will occur.

However; water and the finished wort, aren't anywhere near the same specific gravity. The best example that you can see if simple.

Take a glass, fill it with water 3/4 of the way full. Top it off with maple syrup. Both are thin.

Pour the syrup in as rough as you'd like. Watch the bottom of the glass.
It'll collect most of the heavy gravity syrup. The water will taste sweet, but mix it up, and taste it again... it'll be sweeter.

Click to expand...

I agree the black and tan was not a great example, but syrup isn't either.
The sugar in the syrup is not in solution. I gave that example in a earlier post. The tequila sunrise is a better example than the black and tan or water and syrup.

WoodlandBrew said:

The sugar in the syrup is not in solution

Click to expand...

Sure it is. When you're making maple syrup, you actually measure the process with a hydrometer or refractometer. I'd say it's pretty similar to the tequila sunrise example, since grenadine is basically a pretty high SG sugar syrup.

zachattack said:

I'd say it's pretty similar to the tequila sunrise example, since grenadine is basically a pretty high SG sugar syrup.

Click to expand...

Agreed, that is closer. Although maple syup is about 1.300, and Grenadine is about 1.250, and we are talking about a 1.100 wort.

WoodlandBrew said:

I agree the black and tan was not a great example, but syrup isn't either.
The sugar in the syrup is not in solution. I gave that example in a earlier post. The tequila sunrise is a better example than the black and tan or water and syrup.

Click to expand...

When you make maple syrup, it's pretty much like boiling down wort. Maple sap runs like water. You boil it down to concentrate the sugars.. It's very much like wort.

I agree working with maple syrup is like working with a 1.300 wort. That is higher than any wort I have ever made and much higher than what the OP had. The most he could have had was a 1.133 and that would be with 100% conversion and an impossible 100% lautering efficiency. Because he had to top off, insufficient sparge water is likely the most significant issue here, not stratification. stratification may account for half a dozen points at most here.