Darker beer inefficiency?

[ChaunceyB]

Soooo.....I'll admit I'm new to the brew scene. I've done pale ale and smash beers just fine but I just cant seem to get a handle on these darker stouts and porters. I brew 3 gallon BIAB and just cant seem to hit the recipes OG for nothing. Current recipe I'm trying to work with is

6.5# 2 row
.5# Brown
.5# Chocolate
.3# crystal 90

90 min mash @152
10 min mash out @ 170

OG is SUPPOSED to be around 1.060 HOWEVER the best I can seem to get is around 1.032. All the grains were crushed at my LHBS (as they all are). I havent had any issues until I started to add the roasted/ darker grains into the mix. I've never had issues hitting my OG when brewing Belgian blonds/pale ales/SMaSH/etc. only with the darker stuff. Is there something I'm missing here? I boiled the wort down a little more to get the OG closer to where I wanted it to be but I'll end up loosing about a 1/2 gallon. Not a big deal but it is slightly annoying.

 

[Gnomebrewer]

If you weren't getting good efficiency with your pale ales, I'd say it was a poor crush at the LHBS. Given that your issue is only with dark beers, all I can think of is that it's due to a pH issue. Are you brewing with really soft water? If so, it might help to add some baking soda to the mash. I can't see a low pH causing an efficiency drop this big though, especially with a 90 minute mash.

 

[ChaunceyB]

I do have a whole house water softener. All the grains from the LBHS were all mixed and milled at the same time. All my pale stuff hits the mark every time without even trying. Would it help I wonder if I were to double crush the darker stuff?

 

[schematix]

A few things that immediately come to mind:

1. Your mash pH. Any idea what your water is like? As @Gnomebrewer mentioned this would be the most suspect variable. If you have very pure water it's possible your pH is out of range.
2. Thermometer accuracy - are you sure you're at 152? Is this the same 2-row you used in your paler beers?
3. Are you stirring or recirculating at all?

 

[schematix]

I do have a whole house water softener. All the grains from the LBHS were all mixed and milled at the same time. All my pale stuff hits the mark every time without even trying. Would it help I wonder if I were to double crush the darker stuff?

You don't want to use softened water for brewing. The sodium is off the charts.

I assume if you have a softener though you have hard enough water that someone thought it was necessary to put a softener in. Usually, although not necessarily, this means your water is fairly alkaline too, which is good for dark beers.

Any chance you have a picture of the crush?

 

[ChaunceyB]

Water is defiantly soft. I've used a dial and digital thermometer and both register 152. I pull the top off every 30 min or so to stir and poke stuff around to make sure everything is going well and the temp hasn't fallen off to much. The 2 row is the same ol stuff I normally use.

 

[ChaunceyB]

I wish I would have thought to get a pic of the crush. Might be helpful huh? The softener I have uses either potassium (which is whats in there right now) or salt (which I've never put in there)

 

[Rob2010SS]

So, i don't know if it's the same for BIAB, but for me, bigger beers with the higher OGs typically do a bit poor on the efficiency side. My typical efficiency is 75-80. On bigger grain bills i think my last one was 64%.

Is your grain bill for this significantly bigger that previous brews?

 

[Rob2010SS]

The attached shows a bit of the relationship between grain weight and efficiency. This was given to me to help explain the lower efficiency in big beers

 

[ChaunceyB]

That was my initial thought too but the grain bill for this brew is right in line with all the other brews I've done. I try to keep around the 1.060 or lower mark for all of my brews. High ABV and my drinking style don't mix well at all. So the grain bills are around 7 - 7.5 #'s.

 

[Rob2010SS]

That was my initial thought too but the grain bill for this brew is right in line with all the other brews I've done. I try to keep around the 1.060 or lower mark for all of my brews. High ABV and my drinking style don't mix well at all. So the grain bills are around 7 - 7.5 #'s.

Hmmm ok. Then that nixes that thought. Im going to have to agree with others, that its gotta be a water chemistry/pH issue with the darker/roasted grains

 

[TGFV]

How much water are you mashing&sparging with?

How long are you letting the bag drip?

How fine is your crush?

For a 90min mash I don't see the time being a problem, though the temp may be one.

Otherwise I can only think of PH and chemistry, but even then a 50% efficiency compared to the mid 70s is a lot.

 

[ChaunceyB]

Mash water for that last brew was 5.17 gallons. I pulled the bag and let it drip until the wort was not streaming out then I put the bag in a colander and let it drip until it wouldn't drip no more. (less than half a qt) and dumped that all back into the kettle before the boil. Didn't get a pic of the crush but it wasn't any different than what I usually get from the LHBS.

 

[Hermit]

You could try and use distilled or reverse osmosis water for one batch and follow the guidelines in the water primer for one batch and see if that nudges you in the right direction.

 

[Gnomebrewer]

Water is defiantly soft.

Are you sure? It would seem odd to use a water softener if the water is already soft. Or do you mean it's soft after going through the softener? I'm going to repeat what schematix said earlier - don't use water that has gone through a softener. Find out what is in your water and either use it, or replace it with RO water. I still can't see this being a pH issue though - a low pH may cause some issues, but it shouldn't have that much of an effect on efficiency. How many dark beers have you brewed that have had this problem? I'm leaning more towards it being random that your dark beers have been affected, with the issue being the LHBS crush.

 

[Silver_Is_Money]

Water softeners do not remove alkalinity at all. They completely remove calcium and magnesium and replace it with sodium. Calcium is beneficial to the mash.

 

[cactusgarrett]

I could be wrong, and many people much smarter than myself can chime in, but I don't think any amount of water chemistry (namely mash pH) could be so off so as to cause a 30 point hit to mash efficiency - conversion or lautering. I would expect skewed chemistry to affect yeast health during fermentation, but not extraction to the point of a hit to extraction to that degree. Problem is that nothing else comes to mind. I would be more apt to look at inaccurate temps.

How many times has this happened? Could it be dumb coincidence that the time(s) you do a dark beer your LHBS mill gap could be off?

 

[Silver_Is_Money]

Your deep roast and crystal containing grist for the recipe above has only an average potential of around 34.9 points per pound vs. 37 points per pound for a lighter beer recipe. That in itself reduces your potential efficiency by about 6%. If you assume a course grind efficiency of about 78% for this grist, then 34.9 x .78 = 27.2

(27.2 points x 7.8 pounds) / 3 gallons = 70.7

So if your'e efficiency was 100% perfect, you should be able to achieve an OG of 1.0707. For the 67% efficiency which seems to be rather typical of many beginners it should come in at about 1.0474 OG. From there to 1.032 is a big hit. Perhaps at least some of this hit is the penalty that comes from not sparging?

 

[Hermit]

The primer gives a safe starting point and if the OP is using softened water they'd be advised to go to RO water regardless. This simply points to a standardized path that helps eliminate variables.

BIAB may take a hit in terms of how well the wort will ferment because I think you get more particulate matter. At least that was my experience. My BIAB efficiency wasn't as much of a problem as my ability to ferment to the numbers I wanted.

 

[Silver_Is_Money]

It's clear that the kit manufacturer is assuming 85% efficiency. That is pushing it into the realm of the very best efficiency achievable by home-brewers.

60/70.7 = 84.9%

It looks like adding an extra 1.5 lbs. of 2-Row base malt to kits of this 3 gallon yield size would be a simple and wise move for beginners.

 

[Silver_Is_Money]

If you add 1.5 extra lbs. of base malt no one will ever taste your beer and tell you that it tastes as if your efficiency was low and you had to intentionally compensate for it. Keep the secret to yourself.

 

[Gnomebrewer]

If you assume a course grind efficiency of about 78% for this grist, then 34.9 x .78 = 27.2

(27.2 points x 7.8 pounds) / 3 gallons = 70.7

So if your'e efficiency was 100% perfect, you should be able to achieve an OG of 1.0707.

My understanding is that you either use coarse grind efficiency OR potential as ppg.
So, based on 7.8lbs of grain, 3 gallon batch, average 36ppg or 78%.
100% efficiency = 7.8 x 36 / 3 = 93.6
or
100% efficiency = 0.78 x 46 x 7.8 /3 = 93.3 (the 46 comes from sugar's ppg)

So 100% efficiency is about 1.093. 1.060 would be about 65% efficiency, which is about right for a no-sparge BIAB batch without squeezing (or a light squeeze). 1.032 is about 35% efficiency which indicates a major problem.

 

[Silver_Is_Money]

My understanding is that you either use coarse grind efficiency OR potential as ppg.
So, based on 7.8lbs of grain, 3 gallon batch, average 36ppg or 78%.
100% efficiency = 7.8 x 36 / 3 = 93.6
or
100% efficiency = 0.78 x 46 x 7.8 /3 = 93.3 (the 46 comes from sugar's ppg)

So 100% efficiency is about 1.093. 1.060 would be about 65% efficiency, which is about right for a no-sparge BIAB batch without squeezing (or a light squeeze). 1.032 is about 35% efficiency which indicates a major problem.

I believe you are correct and either coarse grind % or points are to be used as the launching point for a determination of efficiency. I stand corrected.