Adjustments to Mash: Efficiency vs. Fermentability

[TastyAdventure]

I have brewed 3 AG batches and a few partial mashes. My efficiency was 60% and now 65%. My batches have been attenuating between 77-82%!!
Mashing temps have varied, and I've always mashed with a 1.5qt/lb grain.
Mashing times are always 60 min.

What changes can I make (other than always mashing at around 160 F) to INCREASE efficiency but DECREASE fermentability?
Thanks

 

[skunkfunk]

Different yeast will affect fermentability. Different ingredients. Have you checked the grain crush?

 

[mytommygundont]

What's your sparge method? What are your mash temperatures in relation to the type of beer you are making? What kind of yeast are you using?

Some things to think about: Efficiency decreases as gravities rise. So if your beers are bigger, then your efficiency is going to go down. Grain crush could easily be the culpret here. Are you using the HBS's crusher? Usually they have their crush set lighter than I would at my home. PH level could also be a factor. PH directly relates to enzymatic action during your mash. It can affect the fermentability of your wort as well as cause off flavors in your finished beer.

Regardless we probably need a little bit more information about your process before coming to conclusions.

 

[TastyAdventure]

My crush could probably be better, I do it at my LHBS.
I batch sparge. Depending on the style I'm making, I do 150 for light body, up to 160 for full, or in between.
Also depending on the style, I use different yeast, that have "average" attenuations ranging from 73 to 80. The reason I'm looking for other factors/solutions is because, one example, I mashed at 160 and got 80% attenuation out of it. Similar things have happened with other bathes.

 

[TastyAdventure]

Once again, I mashed at 161 F, and my British Ale yeast fermented at 82%. Now I did mash for 80 min (not planned, time got away from me) but shouldn't it have attenuated a lot lower than that regardless? Ugh I can't figure this out. All I want is reasonable attenuation % per yeast strain

 

[RM-MN]

Once again, I mashed at 161 F, and my British Ale yeast fermented at 82%. Now I did mash for 80 min (not planned, time got away from me) but shouldn't it have attenuated a lot lower than that regardless? Ugh I can't figure this out. All I want is reasonable attenuation % per yeast strain

Try mashing for less time. Use iodine to test for starch to make sure you have full conversion. Try the iodine at 10 minutes, 20 minutes, etc. Make sure to get some grains in with the wort when you test because it not all of the grain has converted you will have starch haze in your beer.

I have 2 batches in the fermenter yet that I mashed for only 10 minutes. One had an OG of 1.052, mashed at 152 F and a couple days ago the gravity was down to 1.008 using a full packet of Nottingham for a 2.5 gallon batch. The other had an OG of 1.060, mashed at 154, and half a pack of Windsor yeast. It is currently at 1.018 and seems steady there.

 

[TastyAdventure]

. PH level could also be a factor. PH directly relates to enzymatic action during your mash. It can affect the fermentability of your wort as well as cause off flavors in your finished beer.

.

I have never taken a pH reading. If a wort is TOO fermentable, does that mean the pH is likely too high, or too low?
I'll go get some pH strips before my next brew. I'm also going to get some calcium and chloride, according to this calculator: http://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/

Or should I mess with brew salts before knowing the ballpark of my mash pH?

 

[ram5ey]

Have you calibrated your thermometer? If that is off you could be mashing lower than you think...

 

[TastyAdventure]

Have you calibrated your thermometer? If that is off you could be mashing lower than you think...

Yes I have

 

[stpug]

I had a period of high attenuating beers (80-82%) and it turned out the reason was a gradual temp drop during mashing. The resulting beers were unbalanced on the bitter side, light body, with ever so subtle of an astringency or acidity to them. It's important to get a GOOD and REALISTIC temperature at the end of your mash to judge how much temperature drop you've had during the mash. The only way to do this is to, at the end of mash, stir it all up really well and get a temp reading (the stirring being the key factor); only then will you know an accurate amount of degrees you've lost during the mash. I've since corrected this problem by preheating my MLT, ensuring I get an airtight seal on the cooler lid, and refreshing the mash temp a mid-way through the mash using a small amount of boiling water, and have not had the extreme high attenuations I had been getting. Prior to the changes, I was consistently getting a FG several-to-few points lower than expected. Since making the changes, my FG is hitting exactly were I expect or within one point.

Not so coincidentally, these over-attenuating beers came about after having to swap MLT coolers. I had an old 5G round cooler that developed cracks, so I swapped it out for a new 5G round cooler. Turns out the new cooler doesn't give a great seal on the lid - no matter how hard I cranked it - and it had additional insulating foam which is good in the long run but it initially means more mass to suck temperature away from your mash until it's equalized. Aside from preheating the MLT to warm up the insulation, I've taken to the practice of laying out a sheet of plastic wrap across the top prior to cranking on the lid. Once I did this, the seal was virtually airtight (which is easy to check by simply sealing up your empty cold vessel and blowing through the ball valve).

Hope this helps!

 

[BackAlley]

Surprised no one has mentioned using dextrin malt to add body.

 

[stpug]

Surprised no one has mentioned using dextrin malt to add body.

I think the issue is more to do with over-attenuation and FG, and less to do with body. I think

 

[TastyAdventure]

Surprised no one has mentioned using dextrin malt to add body.

Someone did suggest this to me on BeerAdvocate. In My latest recipe mentioned above I added 1/4 pound to it. We'll see how it is!

 

[BackAlley]

.25 pound may be too little to notice. I'm working on Janet's Brown right now that has 1.25lb

 

[TastyAdventure]

I had a period of high attenuating beers (80-82%) and it turned out the reason was a gradual temp drop during mashing. high attenuations I had been getting. Prior to the changes, I was consistently getting a FG several-to-few points lower than expected. Since making the changes, my FG is hitting exactly were I expect or within one point.

Not so coincidentally, these over-attenuating beers came about after having to swap MLT coolers. I had an old 5G round cooler that developed cracks, so I swapped it out for a new 5G round cooler. Turns out the new cooler doesn't give a great seal on the lid - no matter how hard I cranked it - and it had additional insulating foam which is good in the long run but it initially means more mass to suck temperature away from your mash until it's equalized. Aside from preheating the MLT to warm up the insulation, I've taken to the practice of laying out a sheet of plastic wrap across the top prior to cranking on the lid. Once I did this, the seal was virtually airtight (which is easy to check by simply sealing up your empty cold vessel and blowing through the ball valve).

Hope this helps!

My mash tun maintains temps very well. I will be sure to check extra thoroughly next time though. Thanks

 

[pdxal]

How about more information?
Could you post a full recipe, parameters for the mash, including temp of grain and temperature of water at mash in, and the yeast for us to help you out? Are you stirring and measuring temps? How are you measuring OG and FG? Do the beers taste good?

 

[gwapogorilla]

I have brewed 3 AG batches and a few partial mashes. My efficiency was 60% and now 65%. My batches have been attenuating between 77-82%!!
Mashing temps have varied, and I've always mashed with a 1.5qt/lb grain.
Mashing times are always 60 min.

What changes can I make (other than always mashing at around 160 F) to INCREASE efficiency but DECREASE fermentability?
Thanks

Are you using a brewing software? If yes, which one?
Incorrectly setting up your brewing software will show you have an eff. of 65%, when you may actually have 78% eff.
Crushing your own grain? If yes, what's your gap setting?
Crush quality has a profound impact on your eff. and gravity numbers.
Is your mash tun isolated?
You have been mashing at 160* but getting too much fermentation (low final gravity) and you have a good thermometer. I would say your mash tun is losing heat. I use an isolated igloo cooler, if I single infuse a mash...temp drops 1* in 45 minutes.
Do you "preheat" your cooler?
I pour about 2 1/2 gallons of boiling water into mine, cover, and let sit for a good 20 minutes to preheat. If your not preheating, your mash heat is being lost into the cooler itself. Bringing your 160* mash down to around 145*...a very fermentable beer.

 

[Weezy]

Yeah, I think we need some more information. You're problem is counterintuitive. Mashing that high should get you; a wort with complex sugars and dextrins,which means lower attenuation.
Please let us know your recipe and process.