First all grain attempt, low OG

[PitRow]

[I apologize in advance for the long post]

First a little background: I'm not new to homebrewing, my brother and I used to do it 10 or 15 years ago frequently, though only extract and partial mash, nothing all grain. Never had a "bad" batch, though some that were flat, or a little off, etc. Anyway, fast forward 10 years and my wife has expressed interest in home brewing... Sweet! So I ordered a 1 gallon summer wheat kit from brooklyn brewshop.

That was 4 months ago. You know, life gets in the way. Anyway on Saturday we finally had a chance to brew it. It went ok.

2 quarts of strike water up to 170 degrees, mashed in and the temp dropped to 151 as expected.

Put the whole pot in the oven at 150 degrees for the hour mash. Here's where the weirdness started. Every 15 minutes or so I'd stir it and check the temp, but I'd get wildly fluctuation temp. In one spot it'd be 145 degrees, an inch or two over it'd be 170 degrees, and on the other side of the pot be somewhere in the 150s. This happened every time I'd check. I'm quite certain my thermometer is good, I used my thermopen that had recently been calibrated. I'm a little confused about the wide range in temps. I can see the bottom that's closer to the heating element getting hotter, but I would have thought with a good stir (and I did stir very well) it'd all be evened out and I'd get reasonably close temps. Anyway, the mash continued for an hour, with me concerned over the mash temp the whole time.

After an hour I mashed out to 170 (or at least my best guess at it since I was still getting wide temp readings), and had a gallon of sparge water at 170 waiting. Sparging was done by pouring the mash into a strainer over another pot, then ladeling the sparge water over the grain bed, followed by sparging the whole thing over the grain bed a second time.

Boiled for an hour with a light boil, just enough to keep the wort circulating, not a full rolling boil. Stirred occasionally and when the hops were added. After the boil, into an ice bath and got the temp down to 70 in about 5 minutes. Poured the wort through a strainer/funnel into the carboy and hit issue number 2. Much more boil-off than I'd anticipated. I only ended up with a little more than half a gallon of wort. I topped it off with distilled water, then hit the final problem. I measured the gravity and after correcting for temp came up with 1.025. Much lower than I would expect, though the directions from BBS don't list gravity. It has me a little worried.

Anyway, I pitched the packet of dry yeast and let it go. Sunday morning it was going gangbusters and nearly overflowed the catch basin I had the blow off tube in.

So, sorry for writing a book, but long story short: is the OG too low? I'm expecting that this will probably be a low alcohol beer with such a low OG. Is there anything I could have done, or can do at this point to bring it up? I thought about boiling some DME and adding it, but I don't have any on hand and at this point it's kind of late I'd think. Second question is, are the widely varying mash temps normal, or did I do something to piss off the beer Gods?

Thanks!

 

[Psylocide]

You added a bunch of straight water to the wort... that's your OG problem.

What was your post-boil gravity?

Did you account for grain absorption in your water volume calculations?

You could boil up some DME and add it now, I've done it once when I made a big mistake in measurements, but that beer didn't turn out so great... of course, there were a plethora of other mistakes I made (first batch).

 

[PitRow]

You added a bunch of straight water to the wort... that's your OG problem.

yes, but if the sugar in the wort is in the wort, the boil off of water during the boil would only intensify the OG, and adding the water back should just bring it back to where it should be, wouldn't it?

 

[Psylocide]

yes, but if the sugar in the wort is in the wort, the boil off of water during the boil would only intensify the OG, and adding the water back should just bring it back to where it should be, wouldn't it?

You're right on that part. But, what was your pre-boil OG? Did you take one?

If you had low conversion to begin with, and just added top off water to get to volume, then it's a problem.

 

[PitRow]

unfortunately I forgot to get a pre-boil gravity, never had to do that with extract brewing

 

[Psylocide]

unfortunately I forgot to get a pre-boil gravity, never had to do that with extract brewing

What brewing method? Did you use a mash tun or BIAB?

Also, how fine was your grain crush? Did you get them crushed from the supplier?

 

[cyanmonkey]

What water did you mash with? Have you calibrated your hydrometer?

Those are also some old grains and this is going to sound dumb, but you crushed the grains, right?

 

[PitRow]

It was crushed from the supplier. I'd call it a medium grind I guess. a little finer than steal cut oatmeal I think.

I don't know what method you'd consider this, the mash was steeped in a regular pot then poured through a fine-mesh strainer followed by the sparge water.

Thanks for your help so far btw.

 

[Onkel_Udo]

Best guess?

You oven is unable to maintain 150 degrees. If it is an older gas oven (maybe electric as well), is could easily be heating the back of the pot significantly more than the rest. This means 1/3 or so of you mash was having the enzymes denatured...and then you would stir it expose a new portion of the mash to the hot spot.

Next time, just through it in a pre-heated oven and turn it off. or drop it in a preheated cooler...pot and all.

 

[PitRow]

What water did you mash with? Have you calibrated your hydrometer?

Crap didn't think about calibrating the hydrometer, will have to check that tonight. Mashed with straight tap water, which is pretty soft.

 

[Psylocide]

It was crushed from the supplier. I'd call it a medium grind I guess. a little finer than steal cut oatmeal I think.

I don't know what method you'd consider this, the mash was steeped in a regular pot then poured through a fine-mesh strainer followed by the sparge water.

Thanks for your help so far btw.

Oh... the issue may have been that there was a ton of liquid absorbed by your grains. Most BIABers squeeze the heck out of the bag to get all of the wort out of the grains.

If this was skipped, I could see a significant amount of wort/sugars left behind in the grain and efficiency could suffer because of that.

Wort left in grain + coarse crush could be the issue. I would read up a bit on BIAB and for your next shot, mill to almost flour, squeeze the bag like hell and account for grain absorption in water volume calcs.

 

[PitRow]

Best guess?

You oven is unable to maintain 150 degrees. If it is an older gas oven (maybe electric as well), is could easily be heating the back of the pot significantly more than the rest. This means 1/3 or so of you mash was having the enzymes denatured...and then you would stir it expose a new portion of the mash to the hot spot.

Next time, just through it in a pre-heated oven and turn it off. or drop it in a preheated cooler...pot and all.

I was wondering about that. It's an electric oven, but I was wondering if the element was getting the bottom too hot. The only time I heard it click on was for a very short time (like less than a minute) after I'd open the door to stir it. I guess next time I'll just preheat and turn it off like you suggest. Or go the cooler route.

 

[PitRow]

Oh... the issue may have been that there was a ton of liquid absorbed by your grains. Most BIABers squeeze the heck out of the bag to get all of the wort out of the grains.

If this was skipped, I could see a significant amount of wort/sugars left behind in the grain and efficiency could suffer because of that.

Wort left in grain + coarse crush could be the issue. I would read up a bit on BIAB and for your next shot, mill to almost flour, squeeze the bag like hell and account for grain absorption in water volume calcs.

Thanks, I'm definitely looking into BIAB for next time, seems like a lot less hassle.

 

[aprichman]

You probably denatured the amylase enzymes before they could finish their conversion. I would suggest wrapping the pot in a bunch of blankets instead of sticking it in the oven. Losing 5-6F over the course of an hour is going to give you way better results than having hot spots that denature the enzymes.

 

[PitRow]

Thanks for the comments everyone. Getting a plan going for session #2 and will incorporate your comments and ideas.

 

[estricklin]

Many people here are confused about one thing, extraction and conversion are separate things. Even if, all the starches were not converted to sugars, as long as they were gelatinized and extracted into the wort, the hydrometer will measure them, it doesn't differentiate between starches and sugars. So your mash temperatures weren't even, that could be attributed to many things but as others have mentioned, for one gallon batches BIAB may be your best bet.

The best I can tell you ran the wort over the grain bed a second time? This could be part of the problem, I've never done that and cannot say if it would have a negative impact or not but, it could. If you hit your pre boil volume, we know that you did in fact account for the absorption of the grain. Otherwise, you may have not used enough sparge water in the first place. If your sparge water was not hot enough, that could have be an issue too as the sugars do not dissolve into the liquid as easily when the temperatures are too low.

Do a test on the stove with plain water to get an idea of your boil off rate next time, then you will know how much pre boil volume you need, and of coarse try the BIAB.

 

[BigDog007]

I just brewed my first AG recipe yesterday (5 gallons). I hit all of my volume numbers perfectly, however, ended with a low OG as well pre-boil, I forgot to take a gravity reading post-boil so not sure what I ended up with.

This put me at 54% efficiency which was way less than I had hoped for. I'm going to try the following things on my next batch. (I'm doing BIAB by the way)

-Purchased a grain mill so I can get a better crush than what was offered at one of my LHBS.
-Plan on withholding about 2 gallons of water to do a sparge of the grain bag after I pull it out of the primary kettle.
-Going to rig up the a pulley system to let the grain bag hang for a bit longer before squeezing all of the remaining liquid out of it.
-Plan on stirring quite a bit more and paying better attention to my temperature during the mash.

I expected 60% because I didn't have the grain double crushed but was extremely disappointed in 54%, hoping with the changes I'm making I can hit 70%+.

On a good note I used Wyeast 1968, .8L starter on stir plate and this thing is going bonkers, great looking Krausen and airlock is going crazy. Also major activity visible in the carboy.

 

[aprichman]

I just brewed my first AG recipe yesterday (5 gallons). I hit all of my volume numbers perfectly, however, ended with a low OG as well pre-boil, I forgot to take a gravity reading post-boil so not sure what I ended up with.

This put me at 54% efficiency which was way less than I had hoped for. I'm going to try the following things on my next batch. (I'm doing BIAB by the way)

-Purchased a grain mill so I can get a better crush than what was offered at one of my LHBS.
-Plan on withholding about 2 gallons of water to do a sparge of the grain bag after I pull it out of the primary kettle.
-Going to rig up the a pulley system to let the grain bag hang for a bit longer before squeezing all of the remaining liquid out of it.
-Plan on stirring quite a bit more and paying better attention to my temperature during the mash.

I expected 60% because I didn't have the grain double crushed but was extremely disappointed in 54%, hoping with the changes I'm making I can hit 70%+.

On a good note I used Wyeast 1968, .8L starter on stir plate and this thing is going bonkers, great looking Krausen and airlock is going crazy. Also major activity visible in the carboy.

Just curious but is there any reason why you're not using a cooler mash tun? I've been hitting 70-75% on my first few all grain brews and the equipment cost and is pretty small.

 

[BigDog007]

Just curious but is there any reason why you're not using a cooler mash tun? I've been hitting 70-75% on my first few all grain brews and the equipment cost and is pretty small.

Quite honestly I just really like the idea of being able to do my entire brew day in one kettle. Only one kettle to clean at the end of the day which is huge because I'm completely lazy. It isn't really about the money because trust me when I say I've spent a pretty penny on the equipment I have so far including a kegging system.

I don't mind spending the time to get my efficiency up, just want to become consistent so I can make better beer every time I brew.

 

[Psylocide]

Quite honestly I just really like the idea of being able to do my entire brew day in one kettle. Only one kettle to clean at the end of the day which is huge because I'm completely lazy. It isn't really about the money because trust me when I say I've spent a pretty penny on the equipment I have so far including a kegging system.

I don't mind spending the time to get my efficiency up, just want to become consistent so I can make better beer every time I brew.

Mill your grains super fine... I made a lot of flour out of mine and got great efficiency.

 

[TasunkaWitko]

A couple of observations based on my experience with the BBS mixes:

The mash - I had the same temperature fluctuations, all over the board. The first time, I was using a stainless-steel stock pot over a glass-top stove-top, and I was always over-shooting the mark. It would be a bit too high, then a bit too low- I would stir and it would even out, but then get weird again, just like you describe.

The second time, I thought I would be clever, and set the stock pot in the bottom of a thick, cast-iron skillet. This helped quite a bit, but it wasn't perfect.

The third time, however, seemed to be the charm - I simply did the mash in my 6.5-quart enameled cast-iron Dutch oven:

http://www.walmart.com/ip/Tramontina-6.5-Quart-Cast-Iron-Dutch-Oven/11989387

This worked beautifully. No problems at all, and I was able to simply shut the burner off after mashing in. I only had to put the burner back on low a couple of times, and it went very well

I intend to use the same Dutch oven for my brewing from now on, and will probably experiment with setting it in the oven on the lowest setting, next time.

The sparge - The first time, I used a hand-held strainer over a stock pot in a "lauter tun" setup. It worked, but the strainer was just barely big enough to get the job done. Next time, I used this:

http://www.amazon.com/dp/B004I7Y3Q8/?tag=skimlinks_replacement-20

Perfect fit, with plenty of room to sparge - I was able to kind of stir it a bit as I circulated the water, and also squeeze the grain to get all the liquid out that I could get.

After running the gallon of water through the first time, I re-circulate the wort back through the grain twice, and things seem to go well. By the second re-circulating (three times total), the grain seemed to have given up everything it had to give up, so I saw no reason to run it through a third re-circulation.

After that, it was the boil (slow, barely rolling). Each time, I would end up having to top off with maybe a quart of water. One time, I had to use closer to a half-gallon, but that was my fault.

For my brewing, I always use spring water from a nearby source:

http://www.bigspringwater.com/

It's worked very well for me, so no intention of changing.

Hope this helps, Mike ~

Ron