Someone please explain this to me

[LovesIPA]

I'm brewing a wheat beer. It's in the kettle right now, settling out for a few more minutes before I rack it to the fermenter.

Other than a stuck sparge because the copper manifold disconnected from the ball valve, it was a standard brew session.

6 lbs of Rahr malted white wheat
3 lbs of Great Western 2-row
8 oz of Carapils/dextrine
9.4 oz of Crystal 15 (used the last of the bag I had)

Mashed at 149.8 for 1:15. I aimed for 152 but beer smith for some reason cannot accurately tell me what my strike water temp needs to be. I've fiddled with it, but it's a subject for another thread.

I collected 7.5 gallons of wort at 1.057. I have an 8 gallon kettle so it's pretty tough to misjudge the volume when it's within an inch of the top of the kettle. I have gallon marks scribed into the inside which I've been referring to for the past 25+ batches. Beersmith told me my efficiency was 110%. I double checked everything and couldn't figure out what happened. Brewer's friend gave me the same number. This still has me stumped. But wait it gets better.

I boiled for 60 minutes. Kettle volume is now 5.4 gallons, which is exactly where I want it and exactly where it's supposed to be.

Here's the awesome part. My post-boil gravity is 1.055.

I have both samples sitting on the table in front of me. One is clearly hopped and the other clearly unhopped. I'm correcting for temperature using Beersmith's built in hydrometer correction tool.

I'm using a thermapen to check the temperature and I have two hydrometers. One I know reads about 3-4 points high and the other is spot on. I've checked both in 60* distilled water. They both agree on the gravity. Check that - they both agree on the gravities of both samples.

Can someone please tell me what's going on?

Edit: I added pics. The post-boil sample is on the right. You can see the hop debris in the bottom of the sample vessel.

You can see how close the gravities are in the picture. The hydrometer on the left is the one that reads a few points high.

 

[brew_ny]

My post-boil gravity is 1.055

cool the sample I have not had any luck with adjusting readings with hot wort

just my two cents

S_M

 

[ScotBrew]

You're just awesome at making beer?

 

[BryceL]

So if I'm reading this right, your post-boil gravity is reading lower than your pre-boil gravity? I agree, maybe try cooling the samples and read them again.

 

[WoodlandBrew]

36ppg*10lb=360GP.
360/5.4gal=67GP
55/67=82% efficiency.

But I think that still means you're awesome at making beer.

 

[jro238]

No idea what is going on with the measurements but getting a lower gravity after boiling off 2 gal. shouldn't be possible...

 

[PDX_T]

my question would be when and where do you take your pre-boil samples. I've had this happen before where my pre-boil was way off because the sparge rate is so slow, there's no turbulence and the sugars are stratified.

 

[LovesIPA]

I've had problems with adjusting for temperature as well. I usually take a pre-boil sample after sparging is completely done (i.e. I've collected my 7.5 gallons) and before I fire it up to boil, and the post-boil sample after the wort has cooled.

The pre-boil sample is 87.3 degrees. The post-boil sample is 81.3 degrees. The MOST they could be off is a few points. Nowhere near enough to explain this.

I typically get efficiencies in the mid 80's. I fly sparge with a spaghetti colander. I use a copper manifold in a 10 gallon yellow round Igloo.

 

[brew_ny]

The pre-boil sample

is not just you first running ?

 

[LovesIPA]

is not just you first running ?

Nope, I don't bother checking the gravity of the first runnings. I only care about pre-boil and post-boil.

Thanks for all the responses everyone!

 

[brew_ny]

software says with your grain bill at 75 % efficiency your per boil at 7.5 gallons would be 1.039

post boil at 5.5 gallons would be 1.054

so i am not sure whats up

S_M

 

[mattd2]

36ppg*10lb=360GP.
360/5.4gal=67GP
55/67=82% efficiency.

But I think that still means you're awesome at making beer.

but pre-boil was:
Potential extract (approx.) - 10.0875 * 36 = 363 - actual 384
Pre-boil extract - 7.5 * 57 = 427.5
Eff = 427.5 / 384 = 111% WTF
I think that the preboil sample was not a correct representation of the actual preboil wort.

Edit: Check for actual PPG unmbers not just "36 ppg approximation"

 

[brew_ny]

I think that the preboil sample was not a correct representation of the actual preboil wort.

I am leaning in the direction also

S_M

 

[LovesIPA]

software says with your grain bill at 75 % efficiency your per boil at 7.5 gallons would be 1.039

post boil at 5.5 gallons would be 1.054

so i am not sure whats up

S_M

At least I nailed the post-boil number.

 

[LovesIPA]

I think that the preboil sample was not a correct representation of the actual preboil wort.

I am leaning in the direction also

I'd probably think that as well if I were you guys.

Here's exactly what I did. I've done it this way for at least the last 20 consecutive batches:

Note: let's just forget about the stuck sparge. I had to dump the mash into a kettle, re-attach the manifold, and dump the mash back into the cooler. If anything, it would have hurt my efficiency because the manifold was full of grain and everything I rinsed out of it went down the kitchen sink.

- Opened MLT drain valve. Vorlaufed ~3 quarts and poured them back in to the MLT via the spaghetti colander.
- Moved drain tube to boil kettle.
- Over the course of an hour, I emptied the HLT into the MLT. The MLT slowly filled up with wort and the water level in the MLT stayed more or less the same. I was still having lautering problems and had to raise the mash tun up higher so instead of trickling the water slowly into the MLT, I poured it in quart by quart.

I closed the drain valve when I got the boil kettle filled to 7.5 gallons. Again, it's an 8 gallon kettle. If I misread it and underfilled it, my efficiency would be higher, not lower. I could not possibly have collected more than 8 gallons.

I moved the kettle to the burner, attached a spout to the kettle, and drew off 100ml of wort for the sample. What you see in the picture is what I took.

I'm pretty sure this is going to give a good representation of the pre-boil wort.

 

[Hopper5000]

I moved the kettle to the burner, attached a spout to the kettle, and drew off 100ml of wort for the sample. What you see in the picture is what I took.

There's probably your problem, if you didn't stir the wort up before you took a sample from the bottom spout then the more concentrated, cooler, denser wort from your first running's was sitting there. The less dense hotter and lower gravity running's were sitting on the top. I have made this mistake before and thought my efficiency was garbage. Then I remembered that I need to mix it all together and then take a reading...

 

[brew_ny]

I'm pretty sure this is going to give a good representation of the pre-boil wort.

how well did you mix them? if you did not mix them then the wort first added to the pot would have a higher gravity then the second running added to the top of the pot

then you pulled a sample off the bottom of the pot which had the higher gravity wort

I know wort and top off water has to be mixed to beat the band to get a correct reading with partial boils

wort with more sugar should heavier the then wort with less sugar does not mix readily

without active mixing

but again just my two cents

S_M

 

[mattd2]

I'd probably think that as well if I were you guys.

But what I am saying is that it was impossible for you to collect 7.5G of 1.057 wort as there was not enough sugars in the grain to give you that. You have a measurement error in you preboil, either volume (which you are sure you have correct, and I believe you) or OG. Your issue is you did not have 1.057 in throughout your preboil wort - as below it looks like you had "heavy" wort sitting on the bottom and the "lighter" wort sitting on top.

[There's probably your problem, if you didn't stir the wort up before you took a sample from the bottom spout then the more concentrated, cooler, denser wort from your first running's was sitting there. The less dense hotter and lower gravity running's were sitting on the top. I have made this mistake before and thought my efficiency was garbage. Then I remembered that I need to mix it all together and then take a reading...

 

[LovesIPA]

I moved the kettle to the burner, attached a spout to the kettle, and drew off 100ml of wort for the sample. What you see in the picture is what I took.

There's probably your problem, if you didn't stir the wort up before you took a sample from the bottom spout then the more concentrated, cooler, denser wort from your first running's was sitting there. The less dense hotter and lower gravity running's were sitting on the top. I have made this mistake before and thought my efficiency was garbage. Then I remembered that I need to mix it all together and then take a reading...

As soon as I read this, I knew you had to be right. That's the only possible explanation. Damn, I will have to remember to do that from now on.

Thank you for assuring me that I'm not crazy.

 

[Hopper5000]

Ya no problem, to me that makes the most sense and like I said it's happened to me before and I was like WTF!? Happened on my 1st all grain and I thought my efficiency was like 40%.

Anyways, if it happens again even when you stir it all together then we can try to figure it out from there.

 

[rklinck]

On another note, when you use that much wheat, you need to add rice hulls. Wheat malt tends to result in stuck sparges, and the rice hulls provide the husks you need to lauter appropriately.

 

[BudzAndSudz]

If your pre-boil gravity is reading higher than your post-boil gravity, the obvious reason is due to kettle stratification. A boil kettle will almost never be 100% homogeneous, you simply grabbed an unlucky sample from the kettle that happened to be very sugar rich and it completely skewed your results.

 

[LovesIPA]

I actually used a half pound of rice hulls. I replaced the ball valve on my mash tun and I'm still working out the kinks of getting the fittings working together properly.

 

[SchrodingersBrew]

Make sure both your readings are done with the wort at the same temperature...