Consistently high attenuation

[x3la]

I am consistently getting high attenuation for my batches regardless of the yeast strain.

All of my batches are British Ale; Bitter, Porter, Milds etc.. nothing boozy.

My last two brews with Wyeast 1469, I hit 82% for both. For Wyeast 1187 I hit 78%

I make a starter according to BeerSmith or Brewfather's calculations tools and use a stir plate.

My current brew process is on an Anvil Foundry with no-sparge but I have this same issue on my 3 vessel fly-sparge propane setup.

I mash in at 66c for 60 minutes and then mash out by raising the temperature with a ramp time of 8 minutes to 76c and then hold it for 10 minutes.

I achieve 80-83% mash efficiency.

My grain bill is generally 90%-100% Maris Otter, the rest generally being Crystal, milled with a gap setting of .030

I attach two images of what is a typical fermentation in my apartment. I have some excursions above the recommended fermentation temperatures.



Thanks in advance for any help or pointers!

 

[Beerstein]

Have you calibrated/verified the temperatures you are mashing at? A degree or two lower, and you'll get pretty close to complete fermentation. This would be the simplest answer...

 

[x3la]

Have you calibrated/verified the temperatures you are mashing at? A degree or two lower, and you'll get pretty close to complete fermentation. This would be the simplest answer...

The Anvil is pre heated to a strike temp of 68c which I have verified with a Thermapen. The grain is added and the Anvil typically reads ~67c at this point and a reading at the top of the mash with a Thermapen confirms I'm in the 66c-67c range. Down to 66c a few minutes after. I believe that the thermostat on the Anvil itself is optimised for middle of the mash readings.

 

[Bobby_M]

65-67C is a range that generally creates highly fermentable wort. Try 68-69C instead.

 

[x3la]

65-67C is a range that generally creates highly fermentable wort. Try 68-69C instead.

This is completely skipping the Beta-amylase rest? I would be mashing at just the Alpha-amylase rest.

I'm wondering if reducing the time at Beta-amylase rest to perhaps 40 minutes might be another experiment worth trying.

I also have 60 minutes Mash + 8 minutes ramp up to 77c for the Mash Out. That's nearly a 70 minute mash. Perhaps worth reducing it?

Looking at the attached graphs of fermentation temperatures, are there any concerns there?

 

[doug293cz]

This is completely skipping the Beta-amylase rest? I would be mashing at just the Alpha-amylase rest.

I'm wondering if reducing the time at Beta-amylase rest to perhaps 40 minutes might be another experiment worth trying.

I also have 60 minutes Mash + 8 minutes ramp up to 77c for the Mash Out. That's nearly a 70 minute mash. Perhaps worth reducing it?

Looking at the attached graphs of fermentation temperatures, are there any concerns there?

Beta amylase is active at any temperature, until it is denatured. The idea that enzymes only operate in narrow temperature ranges is false (after all the biologic purpose of the enzymes is to create sugar at room temp, or somewhat below, to allow grain to germinate. sprout, and grow until leaves are formed to enable photosynthesis.) Above about 65°C it denatures fairly rapidly, and the rate of denaturing goes up rapidly with increasing temperature. There is another enzyme that most brewers don't know about, called limit dextrinase. This enzyme can make dextrins fermentable, which neither beta, nor alpha amylase can do. This is actually the enzyme most responsible for higher fermentability of worts mashed at lower temps, as it denatures at temps a little below beta amylase.

But in any case, your problem is too much fermentability, so you want to limit the activity of limit dextrinase and beta amylase in order to reduce the fermentability. Thus, you want to mash at higher temperatures.

Brew on

 

[Dland]

How does it taste? might turn out to be a good beer, even if not what was planned. Remember, some brews take some aging, preferably at low temp, to reach full potential.

And this is how we learn, kinda fun isn't it?

 

[x3la]

How does it taste? might turn out to be a good beer, even if not what was planned. Remember, some brews take some aging, preferably at low temp, to reach full potential.

I'm sure it's perfectly drinkable. It's a fairly "simple" beer. I bottle condition everything I brew so I won't really know for another 4 weeks or so. In addition to being boozier than desired, I suspect it will be slightly drier than I would like it to be. I'm trying to replicate something I can't buy where I currently live.

 

[x3la]

Should I not be able to correct this in Beersmith or Brewfather. I know from my current mash profile that I currently hit 82% so can adjust the yeast attenuation and adjust the recipe accordingly to hit my targets?

 

[x3la]

But in any case, your problem is too much fermentability, so you want to limit the activity of limit dextrinase and beta amylase in order to reduce the fermentability. Thus, you want to mash at higher temperatures.

How about reducing mash time? 40 minutes rather than 60?

Or perhaps adjust yeast attention values in Beersmith/Brewfather from 71% to 82% so that the grain bill is adjusted accordingly to compensate?

 

[doug293cz]

Reducing mash time will likely reduce your conversion efficiency, and thus your mash efficiency. This will necessitate more grain to reach the same OG.

Adjusting your yeast attenuation in software, will not actually change much, other than your predicted FG, and ABV. You could then adjust your grain bill to hit a target ABV, but your beer would likely come out even thinner than it does now.

Not sure why you seem hesitant to mash at higher temperatures, which is the traditional way to decrease fermentability.

Something else to try is including dextrin malt (Carapils, maltodextrin, etc.) in your grain bill, as these malts are processed to yield less fermentable wort.

Brew on

 

[x3la]

Not sure why you seem hesitant to mash at higher temperatures, which is the traditional way to decrease fermentability.

I'm not hesitant. I just wanted to explore the effects of other variables.

I'm currently collecting RO water for a repeat of the last batch but with a strike temp of 71.5°C, mash of 69°C/60 min and a mash-out of 77°C/10 mins so that I can directly compare.

 

[sibelman]

My intuition is that adding malt will make the beer boozier and somewhat less dry - heck, it's a heftier beer! Reducing mash time may have some effect on attenuation, but increasing mash temperature will likely have more effect. Changing one thing at a time seems wise.

 

[MikeCo]

With your typical grain bill as described, increasing the mash temperature is what will increase the FG. You could also increase the percentage of crystal or other specialty malts to decrease the fermentability.

 

[hottpeper13]

When I gypsy brew I like doing bitters and milds and my go to yeast is 1469. the last one was mashed at 68*c for 45 min., it was 4 points low ,finished at 4*p and was the maltiest beer ever for a 3.2 % abv. I think this will be my SOP for Big Brew Days.

 

[x3la]

When I gypsy brew I like doing bitters and milds and my go to yeast is 1469. the last one was mashed at 68*c for 45 min., it was 4 points low ,finished at 4*p and was the maltiest beer ever for a 3.2 % abv. I think this will be my SOP for Big Brew Days.

Why did you opt for a 45 minute mash? Did you mash-out?

 

[IslandLizard]

The Anvil is pre heated to a strike temp of 68c which I have verified with a Thermapen. The grain is added and the Anvil typically reads ~67c at this point and a reading at the top of the mash with a Thermapen confirms I'm in the 66c-67c range. Down to 66c a few minutes after.

Something is off with your temperature readings.

When you add 9-10 pounds of room temp grist, 20°C/68°F, to your Anvil filled with 6-7 gallons of strike water at 68°C/154°F the temps drop significantly. Then the Anvil will take her sweet long time to bring it back up. By that time, the mash is close to done already, and Beta Amylase will have done a superb job of making your wort very fermentable.

You'd need to start with strike water at a much higher temp, say, around 170F (77C).* So your mash temp comes in from above, settling right on your intended mash temp once it's doughed in.

* The actual strike water temp needs to be calculated for your actual grain bill, mash volume, etc.

 

[x3la]

Something is off with your temperature readings.

When you add 9-10 pounds of room temp grist, 20°C/68°F, to your Anvil filled with 6-7 gallons of strike water at 68°C/154°F the temps drop significantly. Then the Anvil will take her sweet long time to bring it back up. By that time, the mash is close to done already, and Beta Amylase will have done a superb job of making your wort very fermentable.

You'd need to start with strike water at a much higher temp, say, around 170F (77C).* So your mash temp comes in from above, settling right on your intended mash temp once it's doughed in.

* The actual strike water temp needs to be calculated for your actual grain bill, mash volume, etc.

So far, for today's brew at an intended 69°C mash temperature:

Grist is 3.53kg (7.78lb) (100% Maris Otter)
Strike water 24.47L (6.46 gallons)

Calculated by Brewfather:

Strike Temp — 71.5 °C (based on grain temp of 22°C - maybe this needs bringing down to 20°C)
Mash In — 69 °C — 60 min
Mash Out — 77 °C — 10 min

Observed:

Foundry @100% (10.5 Gallon 240V) 72°C. Thermapen reads 72.77°C in top middle of malt pipe.
Thermapen reads 69.44°C after doughed in. Foundry reads 70°c. Lid on.

For the entire mash, with power set to 50%, no Thermapen or Foundry temperature reading was below 68C.

I realise that temperatures vary from bottom to top of the mash but I have stirred and recirculated.

 

[x3la]

Something is off with your temperature readings.

Given the readings taken today, do they look better? I can pre-heat to 77°C and allow it to come down to 69°C but it seems like I have hit my numbers by heating strike water to 72°C? If it hangs around at 77°C-69°C for a long time are there any negatives other than adding time to the brew day?

 

[IslandLizard]

For the entire mash, with power set to 50%, no Thermapen or Foundry temperature reading was below 68C.

For these kind of beers the mash temp should not drop below 69C/156F anytime during the mash cycle, from doughing in to mash out. It's indeed essential to perform a mashout directly at the end of the mash, by raising the mash to 77C/170F and hold it there for 10-15 minutes. This to make sure all beta-amylase enzymes are denatured before starting the vorlauf/lauter.

I realize things are a bit different in a Foundry or similar urn type brewing systems, as there's a significant amount of wort underneath the mash pipe that's heated directly while part of it is recirculated to the top of the mash.
It's hard to measure the temp at the center height of the mash pipe (the middle distance between the bottom and top of mash), or even below that.

Just remember when you stick the Thermapen probe into the mash while the wort is recirculating, you're measuring the temp of the mash containing a high percentage of wort that was just pumped from near the bottom of the kettle where the heating elements are located. It may or may not be the exact temp that represents that of the mash underneath.

There also tends to be more heat loss and less wort recirculation toward the sides compared to the center of the unit mash pipe.

Keep good notes, and if you're still getting higher attenuation and lower body than you envisioned, keep raising the "mash temps" 1°C (~2°F) for each successive brew until you hit your final gravity and amount of body just right.

Keep us posted, it may help others using a similar machine like yours. You're not the last or only one who tries to figure this out.

 

[x3la]

Keep us posted, it may help others using a similar machine like yours. You're not the last or only one who tries to figure this out.

I will do!

My 69°C brew OG came in 1 point lower than the last brew with an identical recipe but at 66°C. Nothing else changed. I'm wondering if I should be mashing for longer at this higher temperature? CAMRA's "Brew Your Own British Real Ale" book suggests 90 minutes for both mash and boil. That being said, they also state a 66°C mash.

 

[doug293cz]

I will do!

My 69°C brew OG came in 1 point lower than the last brew with an identical recipe but at 66°C. Nothing else changed. I'm wondering if I should be mashing for longer at this higher temperature? CAMRA's "Brew Your Own British Real Ale" book suggests 90 minutes for both mash and boil. That being said, they also state a 66°C mash.

A 1 point OG difference between two brew runs is not significant. You can get that much change just from the uncertainty in volume measurements. You'd have to do multiple batches at both conditions, and then do something like a statistical "t" test to see if the difference was significant.

Brew on

 

[x3la]

You can get that much change just from the uncertainty in volume measurements.

True. But I do weigh my water on scales.

 

[doug293cz]

True. But I do weigh my water on scales.

You're the exception.

Brew on

 

[Bassman2003]

This is completely skipping the Beta-amylase rest? I would be mashing at just the Alpha-amylase rest.

I'm wondering if reducing the time at Beta-amylase rest to perhaps 40 minutes might be another experiment worth trying.

I also have 60 minutes Mash + 8 minutes ramp up to 77c for the Mash Out. That's nearly a 70 minute mash. Perhaps worth reducing it?

Looking at the attached graphs of fermentation temperatures, are there any concerns there?

Bobby is mentioning the typical single infusion mash which is a hybrid between Beta and Alpha steps. As stated, the hoch-kurz mash schedule produces a more fermentable wort where a single infusion is a little less fermentable. I would wait until you can try some finished beers and let your taste buds drive your decision making. Attenuation, maltiness and body are not one in the same. While possible, your numbers on an Anvil with British yeast and all MO malt seem a little high. But I have limited exposure to your brewing. You might like the beers in the end.

 

[McMullan]

This really isn't that unusual. All it means is you've probably nailed the procedures in your process closer to the optimums. Congratulations! Although it's not necessarily how to make the best beer, for you, at least you have something to work from. If you didn't get consistently high attenuation, after your process, then there would be a problem, if you ask me. As already noted, easiest way to reduce wort fermentability is mash at higher temperature. For a typical (low gravity) English ale it's better to mash at higher temperatures, because final ethanol levels are too low to limit healthy yeast much. Given the chance, full attenuation potential is going to be reached here. Some brewers might consider higher attenuation desirable. Your wort mashed at higher temperature might have had a comparable OG, but it's unlikely to be as fermentable as your previous worts. Be careful about what you read, unless it's up-to-date and from a reliable source. What might have been written (as a general guide) 10-20 years ago might not be that relevant for your specific set-up and process. Things have changed a lot in home brew. Only way to figure out what works for you, in your brewing environment, is empirical observation/good notes.

 

[hottpeper13]

No mashout on gypsy brew day. The idea is to be kinda short and shoddy. As soon as i pull the bag i hit the burner on full.
I have a friend with an all in one system and he does the upward infusion procedure where he mashes in at 64* and it gets to 77* in about an hour.
I would look at it like there's a lot of beer to brew for sensory analysis, which is what I like to do.

 

[x3la]

Well it worked. After 6 days in the fermentor, it has levelled off at ~71% attenuation and I have hit my final gravity exactly:



What is puzzling me is that this recipe, and many others, call for 66°C and list an expected attenuation of 71%. How can this really be the case? Why do I need to mash hotter than others to achieve this? Presumably the attenuation in the recipe is also an indication of the body, mouthfeel and sweetness expected of the beer?

I'm not really finding much evidence online to suggest that mashing at higher temperatures is the norm for British ales.

It's important to me to hit the desired ABV for the recipe. I'm wondering what my tactic should be? Adjust the attenuation I know I hit in the software at lower temperatures and scale the recipe accordingly?

This is an interesting read exBEERiment | Mash Temperature: Low Vs. High In An English Porter

 

[MikeCo]

One other thing to check - is your Tilt accurate in the OG/FG range you are measuring? Mine was a few points off out of the box compared my hydrometer.

 

[x3la]

One other thing to check - is your Tilt accurate in the OG/FG range you are measuring? Mine was a few points off out of the box compared my hydrometer.

Thanks! Yes, they're calibrated.