Problems with hitting og

[southsidebrewingco]

All,

the last two brews ive had a problem getting even close to the og i should be at. Last night i brewed a blue moon clone with a og that was supposed to be around 1.045. After a full 60 minute boil i cooled the wort and topped off with spring water. Added this to my carboy to the 5 gallon mark and shook well to mix and aerate. I then drew a sample to test with my hydrometer (which btw is right on in a water sample) and my og is only 1.030. Any answers as to what im doing wrong?? My last brew also started very low compared to the expected og but it also finished low at 1.004 does this make sense to anybody. Help me with some answers!!!

 

[peterj]

It can be very hard to mix your top up water and concentrated wort thoroughly enough to get an accurate OG reading. This is a pretty common problem with partial boils. But, if you ended up with the right volume of wort and you added all of your extract then you were probably pretty close to the predicted OG of the recipe (as long as the recipe is calculated correctly). Extract has a known and consistent amount of sugar, so when you add that to a measured amount of water you get a predictable and consistent gravity.

Another thing you may want to check out is the accuracy of your hydrometer. An FG of 1.004 is very low (depending on the yeast I suppose) especially for an extract brew. Since both the OG and FG were low, maybe your hydrometer isn't calibrated correctly. It should read 1.000 in plain room temperature water. If it doesn't, you can just add however much it's off to all of your readings.

EDIT: Sorry, didn't see where you said you had tested your hydrometer. But as flars said, if you have one with the paper inside, it can shift.

 

[flars]

You said your hydrometer was calibrated correctly by testing in water. The paper card inside the hydrometer can shift. Give it another check to see if this has happened.

 

[southsidebrewingco]

Good point on the paper possibly shifting it was on my first brew that i checked it in a water sample. I also try to check the wort right at about 70 degrees. I shook the piss outta that carboy i dont know how it could not be mixed well

 

[flars]

Good point on the paper possibly shifting it was on my first brew that i checked it in a water sample. I also try to check the wort right at about 70 degrees. I shook the piss outta that carboy i dont know how it could not be mixed well

You probably have something like this, but maybe another reader doesn't. This is from Palmers' online book. Has a chart for correcting SG readings according to the temperature calibration of the hydrometer.
http://www.howtobrew.com/appendices/appendixA.html

 

[ArkotRamathorn]

You said your hydrometer was calibrated correctly by testing in water. The paper card inside the hydrometer can shift. Give it another check to see if this has happened.

Are there other ways a hydrometer can lose its calibration or change its calibration? I'm all grain so thats a big part of it, but I'll have beers that are as much as .020 off predicted OG, albeit when the beer finishes it (particularly the bigger beers) taste like what the predicted OG/FG should be.

 

[southsidebrewingco]

Im not so much worried about the alcohol content....but if its supposed to be about 5% and im ending up at 3.5% ive either got a problem with my readings or ingredients. My beers have tasted good so i guess thats all that matters.

 

[flars]

Are there other ways a hydrometer can lose its calibration or change its calibration? I'm all grain so thats a big part of it, but I'll have beers that are as much as .020 off predicted OG, albeit when the beer finishes it (particularly the bigger beers) taste like what the predicted OG/FG should be.

I can think of one other way a hydrometer readings may be skewed. The hydrometer may have a hairline crack. Moisture can enter the tube adding weight. The moisture could evaporate over time or more and more moisture can collect until condensation inside the tube becomes apparent.

 

[J187]

Couple of thoughts..

1. You say the OG was supposed to be 1.045, according to whom? I ask this because I have seen a fairly significant variance among some of the online recipe calculators. I have seen beersmith say an OG should be 1.050 and an online calculator say something like 1.057 or whatever.

2. It can be hard sometimes to really accurately measure the 5 gallon volume in a carboy or bucket with foam in the way. Sometimes if you are looking at the mark on the side at an angle, rather than just getting down low and dead on, it can actually be a little higher than the mark. Given the width of some fermenters, this could be a significant jump in volume.

3. I don't know why I never thought of this before, but I think if I was to go back to doing partial boils, I'd probably measure my FG before adding my top off water, and I'd add water until I reached my gravity rather than volume. I can't figure out why that wouldn't work. But I'm tired this morning .

 

[southsidebrewingco]

No moisture. I just checked in a glass of tap water, right on 1.000 what the deuce now im even more confused

 

[J187]

No moisture. I just checked in a glass of tap water, right on 1.000 what the deuce now im even more confused

I'm not sure if you saw my post above your last one, but post the recipe and I'll double check the OG for you.

 

[seph]

I would suggest taking a reading of your wort before you top up. this will give you a better idea of what the OG will be. If you are way off, your post boil gravity will be off, and you will know that it's not your top up water that is throwing you. If the post boil reading is close to where it is supposed to be, than you are getting a bad reading from the top up water.

 

[J187]

I would suggest taking a reading of your wort before you top up. this will give you a better idea of what the OG will be. If you are way off, your post boil gravity will be off, and you will know that it's not your top up water that is throwing you. If the post boil reading is close to where it is supposed to be, than you are getting a bad reading from the top up water.

Awesome... check my latest thread out from a few minutes ago.

 

[southsidebrewingco]

Recipe was combination of oats, pilsen and wheat (4 pounds) steeped this for 20 minutes at about 160 degrees. Added 2 pounds wheat dme and 1 pound pilsen dme for 60 minuts boil. Started with 2 1/2 gallons of water but i think i lost about 1 gallon to evaporation all that grain soaked up a lot. Ended up topping off with 3 1/2 gallons of spring water

 

[seph]

Awesome... check my latest thread out from a few minutes ago.

Ahh, I missed that one. Great minds think alike.

 

[peterj]

Recipe was combination of oats, pilsen and wheat (4 pounds) steeped this for 20 minutes at about 160 degrees. Added 2 pounds wheat dme and 1 pound pilsen dme for 60 minuts boil. Started with 2 1/2 gallons of water but i think i lost about 1 gallon to evaporation all that grain soaked up a lot. Ended up topping off with 3 1/2 gallons of spring water

Oh, it was a partial mash? Well in that case it sounds like you just didn't get very good efficiency from your mash. And I can see why since you mashed at 160F for only 20 minutes. You need to do an actual mash (not just a steep) because you're trying to get a lot of the fermentables from those grains. About 152F-154F for an hour should have worked.

Was that flaked wheat or wheat malt? And was it flaked oats or oat malt? At 160F you probably denatured the enzymes pretty quickly and they didn't have a chance to convert much of the starch from the grains.

 

[J187]

Oh, it was a partial mash? Well in that case it sounds like you just didn't get very good efficiency from your mash. And I can see why since you mashed at 160F for only 20 minutes. You need to do an actual mash (not just a steep) because you're trying to get a lot of the fermentables from those grains. About 152F-154F for an hour should have worked.

Was that flaked wheat or wheat malt? And was it flaked oats or oat malt? At 160F you probably denatured the enzymes pretty quickly and they didn't have a chance to convert much of the starch from the grains.

and.....this is why we needed the recipe

I agree with the above!

 

[southsidebrewingco]

It was flaked. I started the mash at 130 degrees and raised to 160 for the 20 minutes the recipe called for. If steeping at 150 for longer will help im definitely in. Im still learning so the more advice i get the better. Best guess what abv im going to end up with now?

 

[flars]

No moisture. I just checked in a glass of tap water, right on 1.000 what the deuce now im even more confused

The problem has been only with the last two brews? Previous brews were okay?

Your last two brews were LME and DME recipes or partial mash with extract?

If partial mash extraction of fermentables could have been on the low side caused by the mash liquor temp being to high.

The problem has been only the last two brews so your 5 gallon mark may be accurate. Did you mark the carboy with a measured amount of water?

If the recipes are only a combination of LME and DME then I would say the mixing of the top off water and the concentrated wort is the real culprit even though the mixing seemed thorough.

What was the brewed beer and yeast where the FG ended at 1.004?

 

[southsidebrewingco]

Last brew was 4 pounds pilsen dme, 1 pound of corn sugar, 2 oz liberty hops and i tried a package of coopers dry ale yeast

 

[flars]

Last brew was 4 pounds pilsen dme, 1 pound of corn sugar, 2 oz liberty hops and i tried a package of coopers dry ale yeast

Yes, that pound of corn sugar would have dropped the OG to the low digits.

 

[MindenMan]

I have a different way of predicting the O.G. before I top up, you need to know your exact post boil volume. It's really easy, plug in all the information about your brew into beer software, and then change the volume in the software. As your volume goes down, your predicted O.G. goes up, and you can see where you are at that point. The wort needs to be as close 70F as possible to get a stable reading. If, at that point your O.G. is too low, when you run the volume back up you will be able to see how much malt ( DME,LME) you need to add to get to your desired O.G.. I hope this is clear enough to be of help.

 

[J187]

Solved:

From a numbers perspective I will say this:

If you have say 3lbs wheat malt, .5lbs of pilsner and .5lbs of flaked oats, as well as 1lb of extra light DME and 2lbs of wheat DME... IF you get NOTHING from the partial mash, the potential is around 1.031. In other words, if you treat your recipe as an EXTRACT brew, which it essential is if you are merely steeping grains and not partially mashing, then the OG predicted is 1.031 - I just did this in beersmith. IF you change the recipe to a partial mash - and you conduct an actual partial mash getting around 70% efficiency, you will get around 1.046. I think the problem is that in your last two beers, you didn't realize they were "partial mash" brews and treated them like extract only brews. You probably got a little body and maybe some mouthfeel and a bit of flavor from those grains, but you didn't get any conversion - in other words the partial mash recipe is looking for you to create some of your own extract by converting those grains, and then blending that extract (what you made) with the extract you bought.

 

[balrog]

... I think if I was to go back to doing partial boils, I'd probably measure my FG before adding my top off water, and I'd add water until I reached my gravity rather than volume.

This is actually something I've read that is recommended. I'm new (15 batches) to this hobby and have only done partial boils on extract with steeping grain recipes. I have *SEVERAL* times run into issues measuring OG after topping up even tho I use the patented power-drill-paint-mud-mixer-beer-splatters-all-over-kitchen aerate method (followed immediately by the required and equally patented OMG-clean-it-up-before-the-wife-gets-home step)

I have lately therefore taken to drawing sample post-cool, post-dump-to-bucket but **PRIOR** to topping up. It's an extra wait to further cool to reasonable temp for SG reading (I like to be within 10° of calibrated hydrometer temp of 68) but then calculate top up water to get desired OG.

Having said all that, with extracts there's usually not a lot missing in GU unless you've left 10% malt syrup in the can/cannister/bag.

 

[BrewerBrad82]

J187 Nailed it. Im in 100% agreement. A 20 min steep from 130 to 160 would not allow sufficient time for the enzymes in the wheat malt to break down the starches into sugars. It seems like you got a few gravity points out of it, but that steeping is going to provide more haze in the beer than anything else since there are a ton of unconverted starches in solution. But, in a witbier style thats not all bad.

 

[balrog]

Noob Question: I've read Pilsen has ~ 110 diastatic and if the wheat/oats aren't flaked they have none, is there even enough enzyme to convert the starches?

 

[southsidebrewingco]

Its starting to make sense to me now and in theory those numbers i got are spot on with what j187 said.......that being said if i brew the exact recipe again how or for how long should i steep or mash the grains to get all i need from them? Now i wonder if this will taste anything like the blue moon its supposed to.

 

[BrewerBrad82]

Noob Question: I've read Pilsen has ~ 110 diastatic and if the wheat/oats aren't flaked they have none, is there even enough enzyme to convert the starches?

All base malts (2-row, 6-row, pilsen, wheat malt, vienna, munich) are diastatic. A diastatic of power of 110 is more than enough to convert itself as well as a small amount of another non diastatic adjuncts.

 

[peterj]

Noob Question: I've read Pilsen has ~ 110 diastatic and if the wheat/oats aren't flaked they have none, is there even enough enzyme to convert the starches?

Its starting to make sense to me now and in theory those numbers i got are spot on with what j187 said.......that being said if i brew the exact recipe again how or for how long should i steep or mash the grains to get all i need from them? Now i wonder if this will taste anything like the blue moon its supposed to.

Flaked grains have no enzymes. The grain must go through the malting process to develop enzymes. It really depends on how much Pilsner malt was in the recipe as to whether it would have converted. Without knowing the specifics of the recipe there's no way to tell.

So how many pounds of each grain are in the grain bill? You have to have enough pilsner malt to convert the flaked grains as well as the pilsner malt itself. But, for this recipe I would probably go with a 60 minute mash (which is fairly typical) at 152F-154F.

 

[southsidebrewingco]

To be exact it was 2 lbs pilsen malt, 1 lb flaked wheat and 1 lb oat flakes steeped for the 20 minutes @ 150-160