help needed: brewing "tests" ?

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unholymess

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I'm just returning to brewing after a couple years off from getting married, buying a house, moving, etc and am running into an issue with attenuation. With both an ESB and IPA all-grain brew that went nominally well, I can't get past 67% attenuation with yeast that should take me to 73-77% (wyeast 1335). In the hunt to figure out what idiot mistake I'm making, I went looking for brewing practice tests or homework items. Sadly, I'm not finding anything in print or on the web.

I'm looking for tests that might help me fine tune my process with a new rig, water and environment. If you have any ideas, please help a guy out!

One idea I've put together would be to brew an all base-malt beer (American Wheat, Kolsch, etc) that would remove unfermentable grains from the picture. The idea would be to take a 5 gallons recipe, scale it down to 1 or 2* gallons and then brew it a couple different ways to experiment with process changes. The small size would reduce the cost and pain of a possible drain-pour. I'd probably use a dry yeast to eliminate any smack-pack or starter issues - it'd also help eliminate per-batch changes in pitching rates. I'd also take a 1L sample from each and ferment at 80F to get to attenuation quickly just to give me an idea where the base batch _should_ ferment out to.

A couple of tests:
- #1 base run, no changes
- #2 increase mash time by 30min to 90min (use iodine to ensure conversion**)
- #3 drop mash temp 5F
- #4 leave in primary longer than normal (2 weeks instead of racking off at 85-90% attenuation @ 5-7days)
- #5 ferment in basement @ room temp - perhaps heating/cooling in fridge is capping action?

* any magic to scaling a batch down ? Is 1 gallon too small to brew with the same process ?
** how the heck do you guys get a wort sample with out debris in it for an iodine test ?
 
- #4 leave in primary longer than normal (2 weeks instead of racking off at 85-90% attenuation @ 5-7days)


Why do you rack to 2ndary so soon? Why not just leave it in the primary for 3-4 weeks and bottle it from there?
 
I secondary as well, but my beers stay in primary for 2 weeks. Secondly, what temp are you mashing at, and are you sure of the calibration of your thermometer?
 
When I used to 2ndary, I would just dump everything from the boil in also. I would leave it there for a few weeks before I went to 2ndary. I never thought that it had ill affects on my beer.

"perhaps heating/cooling in fridge is capping action?"

What do you mean by this? Are you putting it in and out of the fridge during fermentation? If so, then this would cause temp swings and might be a cause if done enough.

1 gallon might be a little difficult to brew. I would think that it would be hard to maintain mash temps. I use a 52qt cooler though.
I don't use iodine strips and attain around 80% eff.
 
When I used to 2ndary, I would just dump everything from the boil in also. I would leave it there for a few weeks before I went to 2ndary. I never thought that it had ill affects on my beer.

"perhaps heating/cooling in fridge is capping action?"

What do you mean by this? Are you putting it in and out of the fridge during fermentation? If so, then this would cause temp swings and might be a cause if done enough.

1 gallon might be a little difficult to brew. I would think that it would be hard to maintain mash temps. I use a 52qt cooler though.
I don't use iodine strips and attain around 80% eff.

The fridge I'm using has a 2 stage temp controller - it is in my garage and summer temps in MN can swing the ambient temps above 75 during the day and below 60 at night. So, I heat and cool it to keep the fermentation temps controlled. For this batch it was heat to 68F and cool below 71F.
 
It sounds like there wasn't much of a temp swing then. Then maybe the fast ferment test is what you should try. I've only had attenuation problems once and it was because i underpitched a huge beer with little aeration.
 
I secondary as well, but my beers stay in primary for 2 weeks. Secondly, what temp are you mashing at, and are you sure of the calibration of your thermometer?

Mash temps were 153F - measured in multiple spots in the 10 gallon Rubbermaid cooler. I checked the thermometers before starting - I have 1 blichman in the boil kettle, and electric probe and a regular dial - I always make sure they agree during the mash water heating at a couple different temps.

It seems I've gotten multiple suggestions for a 2 week primary - is the reason for the longer time to give it time to finish out ? Most things I've read say to take it into the secondary once the primary starts slowing down. For me, that is somewhere in the 4-6 day range.
 
It sounds like there wasn't much of a temp swing then. Then maybe the fast ferment test is what you should try. I've only had attenuation problems once and it was because i underpitched a huge beer with little aeration.

Indeed - I think this is the first thing I'll try. I've heard some craft/professional brewers do this with every batch so they can really know when "done" is "done".
 
It seems I've gotten multiple suggestions for a 2 week primary - is the reason for the longer time to give it time to finish out ? Most things I've read say to take it into the secondary once the primary starts slowing down. For me, that is somewhere in the 4-6 day range.

Most of the literature that suggests removing from primary at 4-6 days has been deprecated by newer research. Attenuation is not the only thing that the yeast is doing in there, they clean up some of the other by-products of fermentation. Nearly every brewer that has tried longer primaries have had favorable results.
I never move to secondary until my hydrometer says so, its not an time thing. If its not quite done, taking it off of the yeast cake early will cause it to stall and never finish (under attenuation). That right there is most likely your problem.
 
the first that jumps out at me is the Primary time.5-7 days is not enough to get the most out of the yeast. I primary for Two weeks then transfer to Secondary for a week. Alot of folks just leave it in the Primary for 4 weeks, some even longer.

Mash Temp is important as well, 5 degrees seems like a big swing to me. I would try mashing at 149-151 and see where that gets you.
 
Most of the literature that suggests removing from primary at 4-6 days has been deprecated by newer research. Attenuation is not the only thing that the yeast is doing in there, they clean up some of the other by-products of fermentation. Nearly every brewer that has tried longer primaries have had favorable results.
I never move to secondary until my hydrometer says so, its not an time thing. If its not quite done, taking it off of the yeast cake early will cause it to stall and never finish (under attenuation). That right there is most likely your problem.

Nothing as much fun as being out of date - something I'm realizing after 2 years off! Do you have a pointer to some of that research & data? I'd like to start refreshing my antiquated days.
 
Also, what is your yeast pitching procedure look like? Do you make a starter appropriate for the OG of the beer you are fermenting?

Mr Malty Pitching Rate Calculator

Under-attenuation can happen when you under pitch. Something you think about...good luck!

Thanks, I forgot to mention that earlier - I'm doing starters from liquid yeast. I'm using pure 02 in the starter, as well as a stir plate.
 
It seems I've gotten multiple suggestions for a 2 week primary - is the reason for the longer time to give it time to finish out ? Most things I've read say to take it into the secondary once the primary starts slowing down. For me, that is somewhere in the 4-6 day range.

There are several benefits to leaving it on the cake for a couple of weeks at a minimum, and almost no benefit. The first reason for a longer primary is to help it attenuate further. The second reason is that the yeast clean up off flavors that they produce during fermentation. You want a large population of yeast to do the clean up. Racking too soon you lose a lot of workers that could be helping your beer.

Ed
 
There are several benefits to leaving it on the cake for a couple of weeks at a minimum, and almost no detriment. The first reason for a longer primary is to help it attenuate further. The second reason is that the yeast clean up off flavors that they produce during fermentation. You want a large population of yeast to do the clean up. Racking too soon you lose a lot of workers that could be helping your beer.

Ed
Fixed that for ya :)
 
Most of the literature that suggests removing from primary at 4-6 days has been deprecated by newer research. Attenuation is not the only thing that the yeast is doing in there, they clean up some of the other by-products of fermentation. Nearly every brewer that has tried longer primaries have had favorable results.
I never move to secondary until my hydrometer says so, its not an time thing. If its not quite done, taking it off of the yeast cake early will cause it to stall and never finish (under attenuation). That right there is most likely your problem.

What's funny, is this is not new information. It has been in print since the late 80's with studies to back it up. We homebrewers just got around to reading it I guess.
 
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