First PM - OG way low. I thought I did everything perfectly?

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MTB

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I've done 9 extract batches and all of them were perfect. Today, I did my first PM and the OG was 1.052. It was supposed to be 1.065. Here's the process of my brew day:

1) Heated 2 gallons to 162* then added 5lbs of grains.
2) The temp dropped down to 153* then I wrapped the pot in a towel and blanket.
3) After an hour, the temp was 152*.
4) I heated 2gal of sparge water in another pot to 170*, then teabagged the grains in that for a few minutes then put the lid on and let it sit for a few more mins (the temp dropped to 159 during this).
5) Took the grains out, added the wort from the mash and started my boil.
6) Did everything like I usually do, then whirlfloc with 10 mins left and added 6lbs of LME at flameout.
7) Cooled the wort to 100* then added 1gal of ice that I froze last night.
8) Aerated the wort by transferring it from my primary to another bucket 6 times.
9) Took my gravity reading and was surprised to see it so low

What did I do wrong??

*notes: I did notice quite a bit of hop sediment in my graduated cylinder when I took the gravity reading
 
I've never done a PM brew, but I think the "tea bagging" is probably not very effective at rinsing the sugars from the grains, so you might have left a lot behind.

How was the grain crushed? And what was it in?

That gravity is so low, it's coming up to like 25% efficiency, which is almost impossible.
 
I think the "tea bagging" is probably not very effective at rinsing the sugars from the grains, so you might have left a lot behind.

This. It sounds more to me like you're just steeping grains rather than doing a true partial mash. You're just not going to extract sugars doing it this way like you would from a true mash.
 
rebel80 said:
This. It sounds more to me like you're just steeping grains rather than doing a true partial mash. You're just not going to extract sugars doing it this way like you would from a true mash.

How am I not doing a true partial mash? I followed the guide that has worked for many others
 
This ain't a tea party. You gotta squeeze it. Use a colander and a pot lid to get the goodness out. And stir it thoroughly during sparge. Then squeeze it again.
 
This ain't a tea party. You gotta squeeze it. Use a colander and a pot lid to get the goodness out. And stir it thoroughly during sparge. Then squeeze it again.

This would definitely extract the sugars, but conventional wisdom would tell you that this would lead to tannin extraction as well. That being siad, I've squeezed the hell out of plenty of grain bags when steeping specialty grains and never noticed any ill effects.
 
HomebrewMTB said:
This ain't a tea party. You gotta squeeze it. Use a colander and a pot lid to get the goodness out. And stir it thoroughly during sparge. Then squeeze it again.

I did stir and squeeze during the sparge. I just don't get how the OG got so damn low...
 
I'm thinking it was the grain crush. My first AG hit my target OG. My second one, a hefeweizen, came in way low. Everybody suggested it was the crush and I emailed Northern Brewer and their response seemed to agree with it and an apology, but that is wheat which is a smaller kernel. I have a grain mill on the way now for my third AG batch.

Rev.
 
I'm thinking it was the grain crush. My first AG hit my target OG. My second one, a hefeweizen, came in way low. Everybody suggested it was the crush and I emailed Northern Brewer and their response seemed to agree with it and an apology, but that is wheat which is a smaller kernel. I have a grain mill on the way now for my third AG batch.

Rev.

Was your first AG from NB? What about the 2nd time around? I might have made mistakes during my first PM, but seriously.....I don't see how they could affect the OG by so much.
 
This. It sounds more to me like you're just steeping grains rather than doing a true partial mash. You're just not going to extract sugars doing it this way like you would from a true mash.

A mash and a steep are the exact same thing from the human's point of view. The difference is just whether you are have starch -> sugar conversion happening.

1 lb of crystal malt in 150*F water = steep
1 lb of 2-row malt in 150*F water = mash

There is nothing wrong with this mash process.

The sparge process might not be ideal, but it should have gotten him more that 25% sugar extraction. That's the only real mystery. Hell, i think you can get more than 25% efficiency even if you don't sparge at all.

As much as I hate to say it, the only thing that makes sense is a mis-reading on the gravity check, or the amount of grain was actually much less than 5 lbs.

When/how did you check the gravity?
 
Was your first AG from NB? What about the 2nd time around? I might have made mistakes during my first PM, but seriously.....I don't see how they could affect the OG by so much.

Both were from Northern. Actually, according to Beersmith I came under on the first one too but I got what the Northern recipe sheet listed. Beersmith said the recipe should give me 1.059 OG calculating for a 75% efficiency. I got 1.054 which is what their recipe listed but according to Beersmith is 69% efficiency. It was my first batch though so it could very well have been me. My second batch as mentioned was also from NB but since it was a wheat I'm thinking it was the wheat crush since I came in at a paltry 56% efficiency! And I know this time it definitely wasn't me. My mash PH was perfect at 5.2, I hit my temps dead on and held them for an hour, stirred the mash well, did a perfect vorlauf and double batch sparge, etc.

When I emailed Northern the response was that they tell their guys to adjust for the different grains but that they often forget to do so and that he'll remind them and apologized. That basically said to me that was what the issue was.


Rev.
 
As much as I hate to say it, the only thing that makes sense is a mis-reading on the gravity check, or the amount of grain was actually much less than 5 lbs.

When/how did you check the gravity?

That's what I think too, but I checked my hydrometer in distilled water and it read 1.000. When I aerate my wort, I transfer between my primary bucket and my bottling bucket. Before the last transfer, I open the spigot on the bottling bucket to get a sample. I let the hydrometer sit in that for 30 minutes before reading.

When I emailed Northern the response was that they tell their guys to adjust for the different grains but that they often forget to do so and that he'll remind them and apologized. That basically said to me that was what the issue was.


Rev.

Should I email NB about this or even lead them to this thread? I feel like I did everything right and it just doesn't make sense for my gravity to be that low.
 
That's what I think too, but I checked my hydrometer in distilled water and it read 1.000. When I aerate my wort, I transfer between my primary bucket and my bottling bucket. Before the last transfer, I open the spigot on the bottling bucket to get a sample. I let the hydrometer sit in that for 30 minutes before reading.

My point was that YOU might have read it wrong, not that the device was in error. :D
 
Haha, no trust me...I read it just fine. Actually, I looked at it about 20 times and each time I was like "There's no way..."
 
Id take another stab @ it before complaining about grain crush to your supplier.

I may have missed it, but you did stir really well when you added the grain at the start of the mash, correct?

relax, have a home brew.
 
You could check for starch conversion using a white plate and iodine,
I would shoot for 160F to mashin, stir very well to ensure everything is wet and at even temp then let it sit for 30 minutes even if it drops below 150 just let it and give the different enzymes time to do their thing.
Stir very well again, check the temp and up or down it to your final target for the last 30 minutes.
When you steep the bag, put it in a coriander and rinse the sparge water through it at the ending.
Best of luck.
 
Id take another stab @ it before complaining about grain crush to your supplier.

I may have missed it, but you did stir really well when you added the grain at the start of the mash, correct?

relax, have a home brew.

Yes, I stirred very well at the beginning of the mash. There isn't anything I can do about it now, but how will my beer turn out?

You could check for starch conversion using a white plate and iodine,
I would shoot for 160F to mashin, stir very well to ensure everything is wet and at even temp then let it sit for 30 minutes even if it drops below 150 just let it and give the different enzymes time to do their thing.
Stir very well again, check the temp and up or down it to your final target for the last 30 minutes.
When you steep the bag, put it in a coriander and rinse the sparge water through it at the ending.
Best of luck.

I heated my mash water to 162 and it stayed at 152 during the entire hour long mash. I stirred again in the sparge water too. So next time I should heat the sparge water in a 3rd pot and pour that through the grains into my brew pot?

Btw thanks everyone for the help! I'm a little OCD and it's really bothering me how I missed the gravity by so much haha.
 
All I would add would be that if you really want to be sure to hit a specific OG you should check your hydrometer reading after the mash and adjust the amount of extract you use based on that result.

I've always had decent consistency with PMs at about 75% efficiency, but I've also had a few outlier batches that came in around 55% for a low and 85% as a high. I've attributed the differences to grain crush as noted in the previous discussion or the mash Ph.

Keep some extra DME around to adjust upwards if you need to or just use less extract depending which way you end up.
 
It could be the grain crush, but my instincts are telling me the you never got the grains hot enough to get a good sugar extraction. The sugars become more fluid the hotter they get, and it doesn't sound to me like they ever really got above 158 or even less. You've got to figure that if it made the water you "tea bagged" in 159, the grains themselves were probaby not much about 154 or so, way too cool to get an efficient sugar extraction. Since you are doing this in a pot, you should have done a "mash out" in the mash portion of your brew by heating the grains up to 168 or so. Then let them sit there for 10 minutes while the sugars thin. As far as your sparge water, heat this to 175. It will come down some when you add the grains, and it is seriously FINE for sparge water to be a little hotter than 170. Tannin extraction is something of a brewing bogeyman. It does happen, but not nearly as easily as people think. 170 degrees is not a magical number where your beer tastes like crap if the grains get hotter than that. Think about a decoction mash, where grains are actually boiled (I did that this weekend.)
If you try this technique next time, I think you will find you hit much closer to your gravity.
 
You've got to figure that if it made the water you "tea bagged" in 159, the grains themselves were probaby not much about 154 or so, way too cool to get an efficient sugar extraction. Since you are doing this in a pot, you should have done a "mash out" in the mash portion of your brew by heating the grains up to 168 or so.

While I agree that a mashout can be very beneficial when lautering and helping to maximize efficiency, I don't think that is the whole story. I mashed a saison, never got above 148, didn't perform a mashout, and still got my usual 75% with my crush.

Maybe the fact that it's in a grain bag makes a difference here?
 
I skimmed the thread but might've missed something, so apologies if this has been suggested, but:

Have you checked to make sure your thermometer is giving accurate readings? It's not something I've had to deal with personally, but a friend recently realized his thermometer was way off, which was wreaking havoc with his brews.

Otherwise, the process seems fine. I've done about half a dozen or a little more PM and AG batches, all stovetop BIAB. Without much squeezing, I still can get 60-70% efficiency. So I'd wager the issue is not directly related to your process, but a specific misstep or malfunction.

EDIT: I should also mention that I don't do a mashout and have typically "tea bag" sparged at 160F in order to get some more conversion. I did this with my most recent AG batch and got 70% efficiency. So while people might nitpick about some of these process elements, I really doubt you can explain such a big discrepancy by something like not squeezing or not doing a mashout.
 
My thought is that there was top off water/ice. It was stated that the sample was taken after agitating, but possibly there was still an area not mixed well??

Another thread recently was about Northern Brewer sending grain that was supposed to be crushed but was not. (this is not a common occurrence at NB) Was the grain crushed?

Sanitize a thief well and take another sample to confirm the low reading.
 
rebel80 said:
While I agree that a mashout can be very beneficial when lautering and helping to maximize efficiency, I don't think that is the whole story. I mashed a saison, never got above 148, didn't perform a mashout, and still got my usual 75% with my crush.

Maybe the fact that it's in a grain bag makes a difference here?

Your probably using a traditional mash tun setup though. Having the grain all cooped up in a bag is really effecting the efficiency I'm sure. I don't mash out either, since I'm using a converted cooler, and I get great efficiency but its much different when the water can wash through the grain bed. Hopefully a BIAB guy can chime in and tell how they get these 85% efficiencys I'm always hearing about.

I'm confident that the mashout step will definitely help the OP though.
 
There seems to be some confusing info going on here. Im new to all grain, but from what ive read, mashing in the 145-150 range will produce a more attenuative beer. My first all grain only got up to around 148 and my efficiency while not the best, was still somewhere in the 60-70% range. So i dont really follow on why getting the grain up to 155 at the beginning of the mash would make a sizable difference. Forgive me if im not understanding something correctly.

Regarding the bag constricting the grain too much; i cant speak for the OP but in my partial mashes the grain bag was stretched around the rim of the pot, with the grain moving around pretty freely in the pot. The bag acts more as a means to easily remove/strain the grain. So cant really see this being a problem. Ive been doing all grain batches now using around 10lbs of grain in a 5 gallon paint strainer bag in a beverage cooler to keep temp & am constistently right around 70% efficiency. This is with no mashout & sparging in a zipzap @ around 170 degrees.

The topoff water could be the culprit, my first two partial mashes i didnt mix well after topping up and had what i thought were very low gravity readings. I was topping off with 2-2.5 gallons though, i believe the OP said he only topped up with 1.. i have no clue if that is enough or too little to account for the low gravity, but i would think its a possiblity.

To the OP, you replied to my last post asking how the low gravity would affect your beer.. if youre concerned, you could consider adding some dme to the fermenter, make sure to boil it in water for 15-20 min first. Ive done this before & the beer turned out just fine.

Lastly, somebody mentioned if the grain was actually crushed at all. This could be possible... not to offend the OP but was it crushed, would you have noticed if it wasnt?
 
It's not that mashing at 155 would effect efficiency... the mash isn't the culprit in this brew in my mind. Its that it never got over 155 in the SPARGE and this is where the efficiency is lost. Also, when the OP said he "dunked" his grains for the sparge, it doesn't suggest what you are saying, grains swimming freely in 170 degree water. It sounds like the outside layer of grain was quickly dipped in water that cooled quickly, and the inside of the grains never even got properly rinsed. Assuming the top off water was mixed thoroughly, I'm positive this was the problem.
 
Funny, I just did a partial mash and my OG was about 10 points higher than it was supposed to be. But I really paid attention during the mashing phase since I am getting into all-grain. So I wanted to treat it like an all grain. I mashed in a mini cooler and everything. I guess my efficiency was really good (or at least better than what the recipe was calculated for).
 
It's not that mashing at 155 would effect efficiency... the mash isn't the culprit in this brew in my mind. Its that it never got over 155 in the SPARGE and this is where the efficiency is lost. Also, when the OP said he "dunked" his grains for the sparge, it doesn't suggest what you are saying, grains swimming freely in 170 degree water. It sounds like the outside layer of grain was quickly dipped in water that cooled quickly, and the inside of the grains never even got properly rinsed. Assuming the top off water was mixed thoroughly, I'm positive this was the problem.

You could be right, but what we call a "dunk" sparge often refers to what Deathbrewer's PM thread mentions: dunking the bag a few times in the sparge water, yes, but then letting it sit for 10 minutes to get a little more conversion if possible, and of course, allowing the hotter water to pass through the grains.
 
Have you checked to make sure your thermometer is giving accurate readings? It's not something I've had to deal with personally, but a friend recently realized his thermometer was way off, which was wreaking havoc with his brews.

I checked the thermometers calibration before I started my brew day and it was accurate.

My thought is that there was top off water/ice. It was stated that the sample was taken after agitating, but possibly there was still an area not mixed well??

Another thread recently was about Northern Brewer sending grain that was supposed to be crushed but was not. (this is not a common occurrence at NB) Was the grain crushed?

Sanitize a thief well and take another sample to confirm the low reading.

Yes, the grain was crushed, but my instincts were telling me they weren't crushed enough. Most of the grains looked whole, but when I squeezed them individually, they would break into pieces easily. I don't know if this makes any sense to you guys, but I'm trying to describe how they appeared and that's hard to do lol

Regarding the bag constricting the grain too much; i cant speak for the OP but in my partial mashes the grain bag was stretched around the rim of the pot, with the grain moving around pretty freely in the pot.

The topoff water could be the culprit, my first two partial mashes i didnt mix well after topping up and had what i thought were very low gravity readings. I was topping off with 2-2.5 gallons though, i believe the OP said he only topped up with 1.. i have no clue if that is enough or too little to account for the low gravity, but i would think its a possiblity.

To the OP, you replied to my last post asking how the low gravity would affect your beer.. if youre concerned, you could consider adding some dme to the fermenter, make sure to boil it in water for 15-20 min first. Ive done this before & the beer turned out just fine.

Lastly, somebody mentioned if the grain was actually crushed at all. This could be possible... not to offend the OP but was it crushed, would you have noticed if it wasnt?

I had my 5gal paint strainer bag wrapped around the rim of my pot too. The grains had plenty of room to move around.

I originally thought it was because I had top-off water too (1gal from ice and maybe another half gal of chilled water) but I poured the wort between 2 buckets 6 times. That should be plenty to mix it well.

It's too late for me to add anything to this brew...just gotta RDWHAB at this point.


It's not that mashing at 155 would effect efficiency... the mash isn't the culprit in this brew in my mind. Its that it never got over 155 in the SPARGE and this is where the efficiency is lost. Also, when the OP said he "dunked" his grains for the sparge, it doesn't suggest what you are saying, grains swimming freely in 170 degree water. It sounds like the outside layer of grain was quickly dipped in water that cooled quickly, and the inside of the grains never even got properly rinsed. Assuming the top off water was mixed thoroughly, I'm positive this was the problem.

After I dunked the grains, I stirred them up, dunked again, stirred some more, then pot the lid on the pot for 10 minutes. Could this still be the problem? A problem that caused me to miss the gravity by over 10 points :mad:
 
Haven't seen it asked yet, but did you hit your volumes? Pre and post boil? I don't see that listed, and ensure it matches the recipe accurately?

Even with a bad sparge, yet good crush and mash, you should still see at LEAST 60% efficiency. Something isn't adding up.
 
It could easily be a problem that cost you 10 points if the grains never really got over 150's. That higher temp is essential in sugar extraction. Also, the fact that you aren't using full volumes takes away efficiency too, and lots of it. Partial boils don't matter so much in extract brewing by mash strike and sparge volumes are very connected to efficiency in all grain brewing.
 
I have about a dozen or so partial mashes under my belt. i have noticed that through out the whole process i lose about 2 gallons to boil off, that being said i always start with a total of about 7 gallons between the mash and sparge water, with about 2.5 - 3 starting off in the mash. by the time the mash is done the grains have soaked up some water, and some has boiled off. after the mash i do like you and do the "Tea-bagging" method with a little bit of stirring and a little bit of soaking. after a bit of draining (i don't squeeze) i combine the two pots and go on with a full boil.

with this process i get pretty consistant results.

Hope you this helps
 
Squeezing grains does nothing but extract up to a half gallon of perfect wort. If you want to try, squeeze the dickens out of your sack into a separate vessel. You'll taste nothing but nice sweet wort.
 
squeeze the dickens out of your sack

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LOL!

Rev.

ugh.gif
 
My electric stove is so awful that I simply steep my grains in the cold water...slowly get it up to 150...it takes forever...then leave the darn bag in until it boils then give it another eternity to reach boil.

I average 65-70 percent efficiency. Although that seems low I've gotten some wonderful 4.8-5.5 alcohol session ales..Steep it a little longer.

Have fun...Relax a lower gravity ale might actually make for a more approachable beer.

Good luck.
 
MTB said:
Nvm on the grain crush....mine looked like this:
https://www.homebrewtalk.com/f36/bad-crush-282702/

I would suggest a much finer crush. I BIAB myself but your PM process sounds exactly like a BIAB with a dunk or batch sparge. I do that sometimes myself when brewing a BIAB batch larger than my kettle would normally allow. I have found that the crush is the most important variable. I crush my grains much, much finer than the photo in the link above. I mash out but I don't squeeze the bag and I get great efficiency. (Too great, sometimes. I'm still fairly new to brewing and trying to fine-tune my process.)

I read a great post on this forum where someone advised to keep crushing until you're scared, then crush it a little finer still.

That said, I think that it's unlikely that your crush was the sole culprit. Because your OG was so far off, it's very possible there was also a measurement error involved somewhere along the line - grain bill, water volume, temperature or gravity.
 
I think robcj has a point... if you don't have to worry about a stuck sparge you may as well grind it into sawdust
 
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