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Controlling Attenuation Through Mash Times

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The mashing regime affects the body. A hotter, short mash will result in a beer with more BODY.

Appreciate this thread greatly and looking for some clarification. We have been fighting pretty much just the opposite problem for a few of our beers and wind up over attenuating beers we want to retain body. We recirc with a RIMS for good temp control and keep bumping up the temp trying to correct the outcome. Last batch was an hour mash at 155 and still finished 6-7 points low and thin. I now believe it is a function of our process. After the one hour mash we are typically draining over an hour for first runnings and then doing a batch sparge for 20 minutes with another hour drain for the second. This long time sitting at cooler temps must be breaking down the non-fermentables.

If we raise the primary mash temp to 170 prior to vorlauf will that "lock in" the ratio of fermentables/nonfermentables? Thanks
 
Appreciate this thread greatly and looking for some clarification. We have been fighting pretty much just the opposite problem for a few of our beers and wind up over attenuating beers we want to retain body. We recirc with a RIMS for good temp control and keep bumping up the temp trying to correct the outcome. Last batch was an hour mash at 155 and still finished 6-7 points low and thin. I now believe it is a function of our process. After the one hour mash we are typically draining over an hour for first runnings and then doing a batch sparge for 20 minutes with another hour drain for the second. This long time sitting at cooler temps must be breaking down the non-fermentables.

If we raise the primary mash temp to 170 prior to vorlauf will that "lock in" the ratio of fermentables/nonfermentables? Thanks

If you like everything else in your process, then I'd do a mash out. My batch sparging takes about 30 min total (drain, sparge, sparge - pump assisted). Yours seems quite long. Typically favoring alpha amylase results in more dextrins (and a higher FG) as it's attack on starch is more random producing a range of sizes of dextrins. It will though attack the ends of chains like beta-amylase does and can produce glucose, maltose and maltotriose (as opposed to only maltose for beta-amylase). So given enough time it will keep working on the dextrins making them smaller and smaller until there is nothing left to act on but limit dextrins (short chains with branches that the amylases cannot cut). I like to remind people that just because one might get a negative iodine starch test, that does not mean that enyzme activity has stopped.
 
I have a pretty good setup for infusion mashing (not a RIMS or HERMS system by any stretch), and two batches ago, I made an Ordinary Bitter. Even though I used a thermowell (might be the problem), my temps read extremely high on the HLT (going to get a heat shield now) and our mash hit 106. I couldn't figure out what was wrong, but then felt the thermowell...HOT. So, I heated up and added more water, but it wouldn't raise the temp that much. Finally, I pulled some of the wort off, heated it up to mash temp and dumped it back in.

Finally, we got the mash to 154 and I let it sit for 60 minutes and then fly sparged with water at 180 (to bring mash to 170).

Prior to brewing I made a starter with 1318 yeast that I had yeast banked with the frozen yeast bank method in an article on HBT. This was first time, and it took about two days to get to high krausen...way longer than a smack pack and starter.

With all the mashing issues I had, I figured I'd have very little if any fermentables. I was pretty pissed actually...the brew day (for many reasons) was quite the disaster. However, the yeast took off like a rocket and I finished (after week and a few days in primary) at 1.009. BeerSmith suggested 1.008 for that style, so I almost crapped my pants. Hahaha. :ban:

The last beer I made (Friday) was a Pumpkin Brown Ale. Mashed at perfect temps...used a secondary digital thermometer. However, I used BeerSmith and mashed out with the right amount of water at appropriate temp, but my mash raised to 180. Not sure what happened there, but I only let it sit a few minutes, vorlaufed almost immediately and sparged quickly. Hit my target, pre-boil volume perfectly.

It, again, is fermenting like mad. The gurgling has been non-stop since yesterday afternoon...before that, it was about every 15 seconds, and then BOOM....jumped quickly and hasn't stopped.
 
Good questions. I unfortunately don't have answers because I also wonder the same things. I think picking a particular yeast strain would make the conversation more useful as there are some yeast strains that will take 1.080 down to 1.010 and some that will not.

I like you idea about dropping the temperature. It doesn't get discussed much. I even asked about a few posts earlier in this thread and got no reply. I like the 6-row idea. ALso perhaps splitting the mash into 2 smaller mashes and then combining to let the beta finish off.

Some thoughts on wort fermentability:
You need an accurate thermometer and accurate ph meter.
Thin mash for fermentability. What can your system handle?
Mash ph that favors beta
malster information. You probably don't get a copy of the malsters grain data when you buy grain at lhbs. All grain is different.
yeast nutrients and aeration technique. general yeast health when added to the wort. Amount of yeast pitched.
accurate fermentation temperature controls. Using techniques like rising temperature and ferementing at higher temps.

There was a podcast or something by Mitch Steele? some guy that worked at Budweiser and Sierra Nevada. He talks about getting IPAs fermented down low.


You also need to understand Why you want to get that low. And also how it effects things like mouthfeel and flavor and possibly exposing flaws in your beer as well.

How much does the maltster and the grain affect the attenuation and does that affect how the grain responds to the mash temp? I had been hitting my OG or slightly overshooting it and coming out just slightly under the projected FG for a couple years, mashing at 152 to 154 BIAB but the brewers malt I got was from Briess. The latest is pale malt from Rahr and mash temp doesn't seem to make much difference but I'm always overattenuating. For example, a pale ale with an OG of 1.056, mashed at 152 was predicted to end at 1.011 but finally quit at 1.004, quite a bit drier than I was wishing for. Raising the mash temp hasn't seemed to help either.
 
How much does the maltster and the grain affect the attenuation and does that affect how the grain responds to the mash temp? I had been hitting my OG or slightly overshooting it and coming out just slightly under the projected FG for a couple years, mashing at 152 to 154 BIAB but the brewers malt I got was from Briess. The latest is pale malt from Rahr and mash temp doesn't seem to make much difference but I'm always overattenuating. For example, a pale ale with an OG of 1.056, mashed at 152 was predicted to end at 1.011 but finally quit at 1.004, quite a bit drier than I was wishing for. Raising the mash temp hasn't seemed to help either.

In my experience, the mash times have even more impact on the attenuation levels. If I want to finish a mid 50's beer above 1.010, I need to begin sparging at around the 45 minute mark. This is a mash that would have rested at 154-156. For a rich ESB I've gone as high as 160.
 
In my experience, the mash times have even more impact on the attenuation levels. If I want to finish a mid 50's beer above 1.010, I need to begin sparging at around the 45 minute mark. This is a mash that would have rested at 154-156. For a rich ESB I've gone as high as 160.

I've been mashing for only 30 minutes and am getting that attenuation using Rahr malt whereas before I was doing the same process with a fine grind and BIAB using Briess malt, mashing for 60 and getting a higher FG. That's why I was wondering about the difference in who malted the grain. Using the same process and a shorter mash time should get a higher FG, not lower.
 
Allow me to further support the premise of this thread.

I have been focused on beers that should be very dry. Very attenuated.

I always do a 90 minute mash with these beers.
I have even mashed as low as 144.
Raised to mashout temps for the batch sparge.

I can achieve nice body through the use of adjuncts high in beta glucans.
 
Conversely, I mash very high for beers that will be earmarked for wild or bacterial fermentation.
As high as 160.

Still using an extended mash time, of course.
 
Yes, this works as well and is the way many of the larger breweries do it. The problem for homebrewers is that most use coolers for MLTs and would have to use infusions to raise the temp. This can be a bit tricky and more difficult than a single infusion mash where you simply change the time needed.

I have a SS MLT that is direct fired and have done several step mashes recently and have been getting better than rated attenuation lately. Luckily none have gone too dry yet.

I use a cooler mash tun and had to adjust my mash temp up the other day. I pulled about 2 gallons of wort off the mash, heated to 210, then put back into mash. This raised my mash temp in the cooler by 4-6 degrees. I didn't think about it at the time, but didn't I essentially do a step mash?
 
I think you actually did something closer to a decoction mash. With a true decoction, you would pull a certain amount of the mash (grains and wort) from the main mash, boil it separately for a bit and then add it back to the mash to step up to the next temperature.
 
I use a cooler mash tun and had to adjust my mash temp up the other day. I pulled about 2 gallons of wort off the mash, heated to 210, then put back into mash. This raised my mash temp in the cooler by 4-6 degrees. I didn't think about it at the time, but didn't I essentially do a step mash?

This is basically a turbid mash used by lambic producers in Belgium. I believe they repeat the process a number of times, as one might in a decoction.
They push a wicker strainer down into the mash to collect only liquid.
 
The aeration done by one of the big brewers is a falling-film stripper--it's not just bubbling air into hot wort, it's a fairly gentle action--the wort falls down a tube surface in a film as the air blows past it flowing upward. As I understand it, it's to remove DMS. They do use a lot of corn and/or rice in the mash. I've read that hot-side aeration should be avoided, in general.
 
I read your post with interest. I brew mostly hoppy ambers bordering on IPA's. I am pretty happy with the beers but some leave a bit of molasses aftertaste and the FG is often about 1012. This idea might be just what I need to perfect the process. By coincidence I brewed a Robust Porter yesterday and used an 80 minute mash rest. I did the same Porter once before and had a stuck sparge, which seemed like an unfolding disaster at the time but was one of my all-time best brews. The stuck sparge took about 30 minutes to resolve (with panic accompaniment). I used a longer, cooler mash rest this time instead of repeating the stuck-sparge method to re-create the brew.
 
Appreciate this thread greatly and looking for some clarification. We have been fighting pretty much just the opposite problem for a few of our beers and wind up over attenuating beers we want to retain body. We recirc with a RIMS for good temp control and keep bumping up the temp trying to correct the outcome. Last batch was an hour mash at 155 and still finished 6-7 points low and thin. I now believe it is a function of our process. After the one hour mash we are typically draining over an hour for first runnings and then doing a batch sparge for 20 minutes with another hour drain for the second. This long time sitting at cooler temps must be breaking down the non-fermentables.

If we raise the primary mash temp to 170 prior to vorlauf will that "lock in" the ratio of fermentables/nonfermentables? Thanks


Holy cow - why an hour long first running drain? I can see a slower drain on the sparge, but even an hour for that seems unnecessarily long. I would think a mashout would help with your problem - I've been pondering doing this in our RIMS but it seems of the people that do run into scorching wort issues, it's those that are raising temp in their RIMS as opposed to maintaining temp.


I'm wondering in reality how many brewers are "controlling [increasing] attenuation through [longer] mash times" because a longer mash in their case = more temperature loss. For those that claim their coolers only lose 0-1 degree still through the duration of the mash, I'm wondering if this is true everywhere in the mash.
 
So I have done a little research on mashing and the science behind it. From what I have read you really are not doing that much more in leaving your mash in the TUN for an extended period of time. The first 20 min of your mash is where all the magic happens. This is where the enzymes convert 80% of the starches to sugar. Then the conversion rate drops off drastically from there on. Anything after 60 minutes in the tun is not doing much more conversion to sugars at that point. Given you will see a little change and you will probably get the same results I do with your longer mash times but, I’m just saying there is an easier way to do it.
This is done by controlling the temp of the mash. The largest of the 3 factors in what starches are broken down into sugars during your mash is the temp. The other two factors being the PH level and the quantity of water which, are negligible in comparison unless you have really soft or hard water.
If you keep your temp at the lower end of the mash temp range (around 148-151) you will be able to break down some of the more complex starches into fermentable glucose which give you higher attenuation and a dry finish. Now if you move the mash temp the the higher end of the range (154-158) you will not break down the long chain starches and will give that malty finish and give you a lower attenuation percentage. This can all been done in the 60 min mash without waiting that extra time.
If you want to get into the weeds about mash temp and schedules check out John Palmers “How to Brew” and look into the chapter on mashing. He goes full nerd on it and give a better explanation than I
 
Actually "How to Brew" says that low mash temp makes a less fermentable wort.

As for your comment on shorter mash times. What's your opinion on having unconverted starch in your beer?
 
Actually "How to Brew" says that low mash temp makes a less fermentable wort.

As for your comment on shorter mash times. What's your opinion on having unconverted starch in your beer?

Aparently John Palmer missed that error because a low mash temperature does make a more fermentable wort.

Unconverted starch means you had a poor quality crush or bad temperature control. If you haven't converted all of it in 60 minutes its because the grains didn't get wet through or your temperature was wrong.
 
I've been using Beer Smith and hitting the target strike water (about 164 degrees depending on grain temp) and the mash temp of about 150 deg for 75 minutes. My ferments with Safale 04, safale 05 or Nottingham seem to go well but the FG is often in the 1018 range (starting from 1046 to about 1056). My current session IPA fermented at 68F for a couple of days and is flocculated. The gravity is 1020. It tastes great but WTF? I just roused the carboy and am raising the temp in the fermentation closet. Any other ideas? Longer mash? Cooler mash?
 
I've read that lower mash temps take longer to convert than higher mash temps and a temp of about 153 was best for a highly fermentable wort because it favors both Alpha and Beta enzymes. If you go lower than 153 maybe you should mash longer since Beta takes longer? I also read starch fully gelanitizes at 149 so going lower than that may not convert all the starch and its possible to have a less fermentable wort.

Personally I like a two step mash (hockhurtz) in each enzymes optimum range and adjust those times according to what kind of fermentability I'm looking for.
 
My first all-grain is having some attenuation issues. Getting stuck around 1.025. Honestly though I'm not stressing, still tastes great. Basically it's just about a bit over 4% ABV versus 6% like I was shooting for. The hops make up for it though and the average person wouldn't even notice the alcohol difference. Going to try to get a bit lower next time and try the longer mash, just because now I know how to fix it.
 
I've been using Beer Smith and hitting the target strike water (about 164 degrees depending on grain temp) and the mash temp of about 150 deg for 75 minutes. My ferments with Safale 04, safale 05 or Nottingham seem to go well but the FG is often in the 1018 range (starting from 1046 to about 1056). My current session IPA fermented at 68F for a couple of days and is flocculated. The gravity is 1020. It tastes great but WTF? I just roused the carboy and am raising the temp in the fermentation closet. Any other ideas? Longer mash? Cooler mash?

You might also want to check the thermometer you are using and verify you are measuring down in the mash and not just the surface water temp. We came across one dial thermometer we had that was fairly new but reading almost 8 degrees higher than three other devices used to measure temperature
 
Your mash targets seem adequate although i've read the strike water should be closer to 170. How long are you fermenting? Fermentation continues for days even after the bubbling stops. Ferment for @8 days in a primary then rack to a secondary for another 4 days. Also, I've found better attenuation with liquid yeast in viles although that could just mean i really suck at dry yeast prep. California ale yeast is known for high atten. and works well in temps as low as 64F. Make sure you aerate the wort for 10 minutes before pitching.
 
I just peeled off 2 separate batches that significantly over attenuated. They were supposed to finish at 1.013 but actually finished at 1.009. Both got mashed for 60 minutes. 45@145 and 15@168. Guess this time Ill try flip flopping those mash times and see whats up
 
My understanding is that you're not mashing at 168. All the enzymes are denatured at that temperature. Mashing at 145 for 45 minutes is going to give you a very dry beer, so you got exactly what should be expected. Try doing the primary mash closer to 150 or 154, that'll give you more body.
 
Mash temps for a single infusion mash should generally be between 148 (light body) and 156 (full body). Much below 148 and you start to get thin, dry and over attenuated. Much over 156 and you start to shut down conversion and get under attenuation. The 168 is for mash out to stop conversion and "lock in" the mash profile before an extended fly sparge. If you batch sparge, you don't really need it.

Once you get into multi-step mashes, you can play around with different temperature ranges to accomplish different profiles. Part of the reason many Belgians have FGs close to 1.000 is that they spend a lot of mash time in the 130s and 140s (that and a lot of candi sugar). I just did an Oktoberfest with three different temperature steps. I'm not sure my pallette is sophisticated enough to tell the difference between that and a single infusion or decoction mash but I take the word of people witb a lot more knowledge than I that it does make a difference. More importantly, I like the results. It's also a fun challenge to manage the whole process.
 
Mash temps for a single infusion mash should generally be between 148 (light body) and 156 (full body). Much below 148 and you start to get thin, dry and over attenuated. Much over 156 and you start to shut down conversion and get under attenuation. The 168 is for mash out to stop conversion and "lock in" the mash profile before an extended fly sparge. If you batch sparge, you don't really need it.

Once you get into multi-step mashes, you can play around with different temperature ranges to accomplish different profiles. Part of the reason many Belgians have FGs close to 1.000 is that they spend a lot of mash time in the 130s and 140s (that and a lot of candi sugar). I just did an Oktoberfest with three different temperature steps. I'm not sure my pallette is sophisticated enough to tell the difference between that and a single infusion or decoction mash but I take the word of people witb a lot more knowledge than I that it does make a difference. More importantly, I like the results. It's also a fun challenge to manage the whole process.

Decoction is a whole different ball game, it adds in the melanoidin flavor for German beers.
 
Your mash targets seem adequate although i've read the strike water should be closer to 170. How long are you fermenting? Fermentation continues for days even after the bubbling stops. Ferment for @8 days in a primary then rack to a secondary for another 4 days. Also, I've found better attenuation with liquid yeast in viles although that could just mean i really suck at dry yeast prep. California ale yeast is known for high atten. and works well in temps as low as 64F. Make sure you aerate the wort for 10 minutes before pitching.

FYI: You do realize you responded to a 4.5 month old thread. No worries...I've done it too.:)

This is a really good thread from 2008 that should be read from the beginning. I'm glad you found it and pointed me to it. Thanks!
 
FYI: You do realize you responded to a 4.5 month old thread. No worries...I've done it too.:)

This is a really good thread from 2008 that should be read from the beginning. I'm glad you found it and pointed me to it. Thanks!
I like when old threads are reanimated. Then there is not so many to try to get through for answers on the same thing.
 
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