Low efficiency SMaSH

[manicmethod]

This is my 5th AG, I'm doing BiaB and have a 15 gallon kettle that is fairly wide so there is a lot of evaporation. I hadn't gotten a full 5 gallons out yet so I've been increasing the water in by a half gallon each batch. Today I got 5 gallons out (starting with 9) but only got 48% efficiency.

There are probably multiple things that could cause this so I'm wondering what the most likely is. I bought a 55lb bag of Thomas Fawcett Pale Malt to do the SMaSH. I put 11 pounds in and got a 1.039 SG.

I've never used the LHBS crusher for my base grains, for my other AG's I bought pre-crushed from BmW. They seemed to be crushed well but I don't have the experience to judge.

I mashed for 90 minutes starting at 154 and dropping to 145, then mash out for 10 minutes at 170.

I don't sparge, I did press down on the grains and let the strainer drip for probably 20 minutes.

Any clues on what went wrong?

 

[avidhomebrewer]

Why don't you sparge? I haven't done a BIAB before, but have many AG batches under my belt. I would highly suggest doing a sparge; it increases your s.g.

I did 2 ag batches today; one with about 11# of grain, another with about 17# grain. I had a sg of about 1.07 and about 1.09. I wouldn't have achieved those gravities without sparging.

Pressing down on the grains will give you a bit more, but it won't really matter much in the big picture.

Perhaps those that do BIAB regularly could chime in, but I think you need to sparge.

 

[Haputanlas]

I'm kind of trying to figure out what your water to grist ratio is.

I'm a little bit confused. Are you saying you used 9 gallons of water for 11lbs of grain? Or 5 gallons of water for 11lbs of grain?

Also, do you have pictures of your grain crush? We could likely analyze it for you.

What kind of water are you using?

 

[Haputanlas]

Why don't you sparge? I haven't done a BIAB before, but have many AG batches under my belt. I would highly suggest doing a sparge; it increases your s.g.

I did 2 ag batches today; one with about 11# of grain, another with about 17# grain. I had a sg of about 1.07 and about 1.09. I wouldn't have achieved those gravities without sparging.

Pressing down on the grains will give you a bit more, but it won't really matter much in the big picture.

Perhaps those that do BIAB regularly could chime in, but I think you need to sparge.

I sparge with BIAB and I believe it helps quite a bit. I've been getting 70-80% efficiency as of late and I think I'd be closer to 60% if I didn't.

The type of "Sparging" I'm talking about is using another brew pot with water at sparge temps. I just dip the bag into this other pot, stir for a few minutes, and remove the bag again. Then I pour the second pot's contents into the first while I begin to add heat for the boil. In the meantime, I hang the bag over the boil pot to drain the rest of the wort into the boil pot until it stops dripping.

 

[manicmethod]

I'm kind of trying to figure out what your water to grist ratio is.

I'm a little bit confused. Are you saying you used 9 gallons of water for 11lbs of grain? Or 5 gallons of water for 11lbs of grain?

I started with 9 gallons in the kettle before adding grains, after mashing and boiling I had 5 gallons left

Also, do you have pictures of your grain crush? We could likely analyze it for you.

No but I'll take a pic when I go get more crushed tomorrow

What kind of water are you using?

Tap water, I haven't gotten a water report though.

 

[Haputanlas]

I started with 9 gallons in the kettle before adding grains, after mashing and boiling I had 5 gallons left

That's a 3.27 Water to Grist Ratio! You should probably be closer to 1.25 - 1.50 for an optimal BIAB mash. I've never gotten anywhere near that high of a ratio and am not sure if that can affect efficiency(doubt it would hurt). I just don't know if there could be any off flavors.

No but I'll take a pic when I go get more crushed tomorrow

For BIAB, you can mill the grain a little bit more fine than when using a traditional mash tun (Don't have to worry about stuck sparge). This will increase efficiency as well.

Tap water, I haven't gotten a water report though.

If you've never checked your water specs and you've also never achieved decent efficiency, checking the report is a must. You might not be converting starches as effectively as you could be. I'd suggest posting that report so others can assist you in this area.

 

[manicmethod]

That's a 3.27 Water to Grist Ratio! You should probably be closer to 1.25 - 1.50 for an optimal BIAB mash. I've never gotten anywhere near that high of a ratio and am not sure if that can affect efficiency(doubt it would hurt). I just don't know if there could be any off flavors.

How do I adjust for the amount of wort after the boil? The only reason I kept increasing it until I got to 9 gallons was because I was ending up short of 5 gallons in the fermenter

 

[mcaple1]

Just use a 1.25-1.5 water to grist ratio and then sparge with an equal amount of water or a little more. Then if you end up boiling off too much, just top off with clean water.

On a side note, why does it seem like people think that if they boil off too much they will end up having less wort in the fermenter...just top up to five gallons...it won't hurt a thing unless you are already having issues with efficiency before topping off.

 

[Haputanlas]

How do I adjust for the amount of wort after the boil? The only reason I kept increasing it until I got to 9 gallons was because I was ending up short of 5 gallons in the fermenter

You can always add water after the mash and before the boil. Or, you can also add more water when you put into the fermenter and pitch.

However, I highly suggest that you add more water after the mash. A full boil is considered the best option for hop efficiency and other things.

Your mash with 11lbs of grain should be between 3.5 and 4 gallons of water to get the water to grist ratio I'd prefer. After the starch conversion in the mash, you can add more water.

 

[emetcalf]

If you have another pot, I would suggest mashing with 3.5-4 gallons like other people have been saying. then after you pull the grain out, put the bag of grain in your second pot with 4-5 more gallons of water (or as much as you can fit in the pot and still get the grain in) and stir it really well, then combine all of the water in the main pot and add water until you get to the 9 gallon pre-boil volume. Or you could do something more like a traditional sparge and just pour hot water through the bag while you hold it over the pot if you dont have another pot big enough to hold 4 gallons of water plus the grain. Either way, use less water in the mash and do your best to rinse the grain after the mash.

Also, if you can turn down the heat a little bit and still get a decent boil you will probably boil off less water and you won't need 9 gallons pre-boil anymore.

 

[manicmethod]

If you have another pot, I would suggest mashing with 3.5-4 gallons like other people have been saying. then after you pull the grain out, put the bag of grain in your second pot with 4-5 more gallons of water (or as much as you can fit in the pot and still get the grain in) and stir it really well, then combine all of the water in the main pot and add water until you get to the 9 gallon pre-boil volume. Or you could do something more like a traditional sparge and just pour hot water through the bag while you hold it over the pot if you dont have another pot big enough to hold 4 gallons of water plus the grain. Either way, use less water in the mash and do your best to rinse the grain after the mash.

Also, if you can turn down the heat a little bit and still get a decent boil you will probably boil off less water and you won't need 9 gallons pre-boil anymore.

Got it, I was following https://www.homebrewtalk.com/f36/biab-brewing-pics-233289/ which was no-sparge and the full amount of water for mashing. I never thought that having more water would harm the mashing process...

I don't have a crazy hard boil, I definitely turn down the heat once it starts rolling. My pot is 20.5" wide so I suspect that is the problem.

Won't adding that much water after the mash greatly reduce the SG?

 

[Mysticmead]

no need to sparge when doing a full volume BIAB. The grains you got previously from BMW had a great crush. when I bought grain there and had them crush it I was consistently getting 75% efficiency. Now that I crush my own I get 80-84%. That's a full volume no sparge BIAB. To determine the water needed it's simple. desired batch size + absorption + boil off + trub loss = water needed. to determine the absorption use grain weight weight x .07 = absorption You can go lower to .05 but the extra cushion is there in case you boil off more than expected. as an example, my upcoming beer will have 9lbs of grain giving me an absorption of .63 gallons. desired batch size is 5.5 gallons, my boil off will be 1.5 gallons and I'll loose .25 to trub. 5.5 + 1.5 + .63 +.25 = 7.88. in this case I'll bump it to 8 gallons the extra will be boiled off by adding an extra few minutes to the boil.

if you are using the grain mill at your LHBS run it through twice to make sure it's crushed completely

 

[manicmethod]

I feel like I'm getting mixes messages here. Is a full volume BiaB going to get high efficiency? Why is Haputanlas concerned about the water/grist ratio?

 

[Mysticmead]

in a traditional mash.. you'd use 1.25-1.50 quarts per pound. however, this isn't a traditional mash.. it's BIAB. the traditional BIAB is full volume no sparge. My last brew had an efficiency of 84%. With BIAB since you can't get a stuck sparge, you can crush finer. My general rule on crush is double crush.. here's an example of my crush

 

[manicmethod]

in a traditional mash.. you'd use 1.25-1.50 quarts per pound. however, this isn't a traditional mash.. it's BIAB. the traditional BIAB is full volume no sparge. My last brew had an efficiency of 84%. With BIAB since you can't get a stuck sparge, you can crush finer. My general rule on crush is double crush.. here's an example of my crush

Ok, so I started with 9 gallons and got 5 gallons out so that seems like a full volume mash to me. Why did I get <50% efficiency?

 

[Mysticmead]

Ok, so I started with 9 gallons and got 5 gallons out so that seems like a full volume mash to me. Why did I get <50% efficiency?

most likely your crush.. it can really be as simple as that. double crush is using a mill at the LHBS..

 

[Haputanlas]

If you are willing to crush your grains as fine as Mysticmead, I would assume you could definitely get higher efficiencies without sparging and also use a different water to grist ratio.

 

[Mysticmead]

with BIAB there's no reason not to crush it real fine. you can't get a stuck sparge with a bag.

 

[redcoat_or_rebel]

and tannins aren't an issue under 170*

 

[Mysticmead]

and tannins aren't an issue under 170*

tannins aren't an issue as long as the PH is correct. temp is only part of the equation. After all in a decoction mash you boil the grains..

 

[Haputanlas]

and tannins aren't an issue under 170*

I have never heard that before. That would be interesting if correct.

tannins aren't an issue as long as the PH is correct. temp is only part of the equation. After all in a decoction mash you boil the grains..

I've definitely heard that.

 

[Psych]

Got it, I was following https://www.homebrewtalk.com/f36/biab-brewing-pics-233289/ which was no-sparge and the full amount of water for mashing. I never thought that having more water would harm the mashing process...

Just to chime in on this topic here, my last BIAB (on Friday) was 9.5lbs of grain and I mashed with 7.5 gallons of water. I ended up with 80% efficiency on the nose. Fine crush, voile bag, but massive amounts of water in the pot and that really helps saturate the sugars out.

My lowest BIAB efficiency was 56%, and on that run I did 11lbs in 4 gallons of water. Much of the grain didn't contact water, lots of clumps even with tons of stirring. It was no good...but YMMV...high water to grain ratio worked great for me.

 

[Haputanlas]

Just to chime in on this topic here, my last BIAB (on Friday) was 9.5lbs of grain and I mashed with 7.5 gallons of water. I ended up with 80% efficiency on the nose. Fine crush, voile bag, but massive amounts of water in the pot and that really helps saturate the sugars out.

My lowest BIAB efficiency was 56%, and on that run I did 11lbs in 4 gallons of water. Much of the grain didn't contact water, lots of clumps even with tons of stirring. It was no good...but YMMV...high water to grain ratio worked great for me.

How much water did you have to boil off to hit your SG numbers? BTW, what was your OG on this batch?

 

[Psych]

How much water did you have to boil off to hit your SG numbers? BTW, what was your OG on this batch?

I don't focus too much on needing to boil off a certain amount, or boiling longer etc, unless my pre-boil is WAY out of whack. But on my good efficiency batch I believe I went from 7.5g down to 6.5g in the kettle during the boil. The OG on this one was 1.044. I was targeting 1.044-1.048'ish but I got an extra quart or two out of it, so really should have boiled a bit longer.

On my low efficiency I was doing a more concentrated wort and topping up with more water after, I think I started the boil with just over 3.5g and wound up with 2g after the boil. This batch was 1.043 OG, I was shooting for 1.052 or so. THough technically since I used top up water my OG was really 1.075 or something....until I thinned it out.

Both those were on different pots, one on the stove and the other full electric.

 

[manicmethod]

most likely your crush.. it can really be as simple as that. double crush is using a mill at the LHBS..

I double crushed some yesterday and did another batch and got somewhere around 55% efficiency. It was a 90 minute mash starting at 154 with 17 pounds of grain in 9 gallons of water.

 

[Psych]

I double crushed some yesterday and did another batch and got somewhere around 55% efficiency. It was a 90 minute mash starting at 154 with 17 pounds of grain in 9 gallons of water.

One thing that I've certainly run into myself is seemingly low or seemingly high efficiency due to me measuring my water volumes wrong, or not adjusting the hydrometer for the temperature of the sample, if above 65F.

A slightly change, half a gallon of water off either way, could give you a 15-20% difference in your efficiency, depending how much water you've got. Maybe calibrate your water calculating mechanism, whatever you use? Make sure anything you use to calculate said efficiency is working correct, basically

 

[manicmethod]

One thing that I've certainly run into myself is seemingly low or seemingly high efficiency due to me measuring my water volumes wrong, or not adjusting the hydrometer for the temperature of the sample, if above 65F.

I always adjust hydrometer reading. I learned that lesson when I was doing extract.

A slightly change, half a gallon of water off either way, could give you a 15-20% difference in your efficiency, depending how much water you've got. Maybe calibrate your water calculating mechanism, whatever you use? Make sure anything you use to calculate said efficiency is working correct, basically

Interesting. Does the stuff left as trub count toward the 'batch size'? I use BrewMate and I set batch size to what went into the fermenter but if I adjust for trub loss the efficiency looks much nicer

 

[Psych]

I always adjust hydrometer reading. I learned that lesson when I was doing extract.



Interesting. Does the stuff left as trub count toward the 'batch size'? I use BrewMate and I set batch size to what went into the fermenter but if I adjust for trub loss the efficiency looks much nicer

I think whatever's in the pot is your water amount for efficiency, at least a pre-boil efficiency, but there's no trub there. Wouldn't for post boil though...or at least I don't count whatever I leave behind, though I don't leave much.