Another low OG, I think?

[gfinockio]

Okay - please bear with me. I seem to be pulling low gravity the past few brews. Here's the grain I used tonight:

4lb 2-row (Manitoba grown)
2lb Vienna
1lb Carapils
1lb 40L

(So total 8lbs)

4 gallons of water for the mash, 160 degrees for 60 minutes.

I added .25 gallon before the boil to top up, and then no additional water. It was supposed to be a 3 gallon batch, ended up just a smidge over 3 gallons after boil off.

OG measured was 1.05 at 30C.

Am I hitting efficiency with what I had? I can't even tell.

 

[gfinockio]

Okay, maybe answered my own question - according to Beersmith, I should be around 1.060 with that combination... so I'm just not efficient enough, but not horribly off. This was more a test of my BIAB skills than anything else.

 

[wilserbrewer]

I would check your crush? Pouring the quart of top up water through the grain bag would also help a little rather than adding straight to the kettle.


Wilserbrewer
Http://biabbags.webs.com/

 

[gfinockio]

I would check your crush? Pouring the quart of top up water through the grain bag would also help a little rather than adding straight to the kettle.


Wilserbrewer
Http://biabbags.webs.com/

Oh, that's what I did - poured the warm water into the bag and then lifted the bag up. Not exactly a "sparge", but something.

The crush is what I tried to improve this time around, actually - I use the mill at the LHBS, but they don't have any sort of way to adjust it, so I just ran the grain through three times. It seemed pretty crushed up?

 

[Yooper]

Okay - please bear with me. I seem to be pulling low gravity the past few brews. Here's the grain I used tonight:

4lb 2-row (Manitoba grown)
2lb Vienna
1lb Carapils
1lb 40L

(So total 8lbs)

4 gallons of water for the mash, 160 degrees for 60 minutes.

I added .25 gallon before the boil to top up, and then no additional water. It was supposed to be a 3 gallon batch, ended up just a smidge over 3 gallons after boil off.

OG measured was 1.05 at 30C.

Am I hitting efficiency with what I had? I can't even tell.

Did you hold your mash at 160 degrees? If you did, that's too warm. But if you added 160 degree water to your mash, your mash was probably in the high 140s and that might be too cool. 152-153F for an hour would be more in line with conversion.

Gee, I sound like Goldilocks- "this mash temperature is just right"!- so sorry about that.

 

[RM-MN]

Oh, that's what I did - poured the warm water into the bag and then lifted the bag up. Not exactly a "sparge", but something.

The crush is what I tried to improve this time around, actually - I use the mill at the LHBS, but they don't have any sort of way to adjust it, so I just ran the grain through three times. It seemed pretty crushed up?

Their mill may be set to wide that you aren't getting a good enough crush even though you triple milled it. I use a cheap Corona mill that I got through Discount Tommy. http://www.discounttommy.com/p-189-...er-for-wheat-grains-or-use-as-a-nut-mill.aspx

You can also get that style of mill from Walmart as a ship-to-store item (free shipping). http://www.walmart.com/ip/29688114?...23897272&wl4=&wl5=pla&wl6=51320962143&veh=sem

 

[gfinockio]

Did you hold your mash at 160 degrees? If you did, that's too warm. But if you added 160 degree water to your mash, your mash was probably in the high 140s and that might be too cool. 152-153F for an hour would be more in line with conversion.

Gee, I sound like Goldilocks- "this mash temperature is just right"!- so sorry about that.

My target temperature was 154F - but it held at 160F for pretty much the entire hour.

Here's what I did - I heated the water to 164F, then I poured the grain in and saw the temperature fall to about 160F, and I turned the burner down to minimum and covered. Checked in 10 minutes to find it still at 160F, so I turned the burner off and stirred. Checked 20 minutes later to find it still at 160F, and just left it.

Would that high of a temperature affect efficiency?

 

[AndytheBeave]

taking your gravity test at 30C is probably a bit high. If I were a betting guy, I would bet your hydrometer is calibrated for 15.5-16 Deg C. Check on the side of your hydrometer and it'll be stamped somewhere on there. If this is the case, it will definitely read low.
I did an experiment last weekend during my brew to see how much the gravity reading would change as the beer cooled, and it was significant.
I first tested it at just over 40 Deg C and it was ~1.042. I tested it again at 23 Deg C (just over my pitching temp) and sure enough it was ~1.050.
Brewers friend also has a calculator for hydrometer accuracy:
http://www.brewersfriend.com/hydrometer-temp/

So, you probably have crush issues, but to be accurate about your efficiency, make sure you are testing your gravity as close to the calibrated temperature as possible.

 

[pricelessbrewing]

My target temperature was 154F - but it held at 160F for pretty much the entire hour.

Here's what I did - I heated the water to 164F, then I poured the grain in and saw the temperature fall to about 160F, and I turned the burner down to minimum and covered. Checked in 10 minutes to find it still at 160F, so I turned the burner off and stirred. Checked 20 minutes later to find it still at 160F, and just left it.

Would that high of a temperature affect efficiency?

Sounds like you have a couple issues with your process.
1) your mash temp is really high/you didn't calculate your strike temp properly.
2) Did you wait to check your OG at room temp?
3) Grain crush may be too coarse.

The first is easy to fix, use BIAB calculator. As usual, I'm going to recommend you use mine, a lot of other calculators don't let you do a sparge option which will affect strike temp. Link in my signature below.

The second is also easy to fix, take a sample out after the wort is cooled and measure the OG. Or measure in the kettle if it's at the proper temp.

The third is up to you, you may be able to convince the LHBS to let you adjust the mill gap. Or you may have to buy a grain bill (30$~) if that's not an option.

However you may find that once you fix the mash temp/strike temp issue you're efficiency goes up to a more comfortable number (70ish+)

 

[gfinockio]

Sounds like you have a couple issues with your process.
1) your mash temp is really high/you didn't calculate your strike temp properly.
2) Did you wait to check your OG at room temp?
3) Grain crush may be too coarse.

The first is easy to fix, use BIAB calculator. As usual, I'm going to recommend you use mine, a lot of other calculators don't let you do a sparge option which will affect strike temp. Link in my signature below.

The second is also easy to fix, take a sample out after the wort is cooled and measure the OG. Or measure in the kettle if it's at the proper temp.

The third is up to you, you may be able to convince the LHBS to let you adjust the mill gap. Or you may have to buy a grain bill (30$~) if that's not an option.

However you may find that once you fix the mash temp/strike temp issue you're efficiency goes up to a more comfortable number (70ish+)

All good advice - this is only my third all-grain BIAB brew, and I'm finding more and more steps to be more careful on. I have a feeling my biggest issues are crush and temperature related during the mash.

 

[TexasWine]

I know some folks pointed out your mash temp was high, but not sure if I read where someone pointed out the impacts of it. You'll likely end up with an underattenuated beer, final gravity will be higher than you intended.

 

[DurtyChemist]

It looks like you lost 4 degrees adding your grains so remember that for the next brew. If you want to mash at 155 I'd get the water to 160 and add grains. Also consider mixing the mash with a mash paddle or spoon about every 10 minutes. It helps.

 

[pricelessbrewing]

I'm going to go against the above. stir once, thoroughly with a large whisk.

Temp loss will depend on strike temp, mash temp, grain temp, and how much grain your adding. Use a calculator or do the math yourself.

 

[DurtyChemist]

I'm going to go against the above. stir once, thoroughly with a large whisk.

Temp loss will depend on strike temp, mash temp, grain temp, and how much grain your adding. Use a calculator or do the math yourself.

Recirculating the mash in a traditional mashing setup increases efficiency. It exposes the grain in the middle to the enzymes much better and BYO just had an article discussing it.

 

[pricelessbrewing]

Recirculating the mash in a traditional mashing setup increases efficiency. It exposes the grain in the middle to the enzymes much better and BYO just had an article discussing it.

I have no doubt that is true for traditional setups, but I imagine it would have less of an impact in BIAB due to the thin mashes often employed. Also will cause greater temp loss.

 

[DurtyChemist]

I have no doubt that is true for traditional setups, but I imagine it would have less of an impact in BIAB due to the thin mashes often employed. Also will cause greater temp loss.

Imagination isn't the best basis for information. Try stirring every 10 minutes next brew day and watch your temps. You'll be surprised what temperature measurements change to when you mix the middle of the mash with the outside 2-3 inches that are typically all people measure and consider to be representative of the entire mash.

 

[pricelessbrewing]

I stir to create an effectively uniform temperature when I measure, but I neither take a mid point measurement during the mash nor do I stir thorough out.

Heat flow is a function of temperature differential, stirring the mash evenly increases that difference between the surrounding environment and the outter layer of the mash. This will increase the heat loss. Moreover the very act of opening the container will cause air disturbance and increase heat loss, as well as replacing the warmed air in the mash tun/kettle with cooler air, thereby increasing heat loss further.

Tl;dr closed recirculation is cool and efficient, but imo open recirculation (stirring by hand) risks too much heat loss for the small efficiency gain that could be had. Especially due to the fact that the grain density (#of grains/cubic volume of wort) so much lower in a typical full volume mash. The point of recirculation is to expose more surface area, which is already done by the full volume.

If you can site a source relevant to full volume mash, and full volume recirculated mash I'd be more accepting.