Open fermentation in a plastic DIY Coolship

[mcbethenstein]

Wow,
There has been quite a bit of discussion on this while I was gone! Suffice it to say, perhaps the depth of the fermenter on a homebrew scale has less to do with the increased ester levels than the psuedo-open aspect of it. But it does make a difference… and a tastable one at that. Even the non-super tasters at our learn to brew day could distinguish the highly ester-y characteristics of this beer. I am still inclined to believe that ratio of surface area to depth is a deciding factor (Although NOT the sole factor). With that level of surface area there is a freer exchange of Oxygen and CO2. Most brewing science out there suggests that increasing Oxygen will actually decrease ester production, which is opposite of what we are seeing here. However there is also info out there that suggests that increasing CO2 concentrations also "scrub your beer" clean. Off flavors and esters are picked up by the CO2 and then driven off after the CO2 is pushed out of the beer and through our blow off tube or airlock. With so much open space, CO2 off gases easily and with decreased concentration in the wort and decreased contact time may allow for more esters to remain in the finished beer. Here is a powerpoint from David Bryant at the Brewing Science Institute that summarizes the findings of many major studies by the german Hefe brewers. It is far less technical and more understandable to me than a number of other references I've come across lately, along with real world observations by the brewers themselves.

http://www.mbaa.com/districts/MidSo...2010-03-13Wheat_Beer_Yeast__Fermentation2.pdf

 

[g-star]

Thanks for sharing that presentation, very informative. I find German wheat beers to be very difficult to nail...lots of great info there.

 

[ABVIBUSRM]

King'd!!!!

 

[mcbethenstein]

So, I thought this tread could use a little update. I decided (was highly annoyed by my club leader) to submit a proposal to speak on at NHC 2015. I was accepted and spoke on the two experiments I chronicled here on HBT and on another.... This Fermenter shape.

I finally put together a side by side full scale 5 gallon brew to compare the fermenter shape...ON A HOMEBREW LEVEL. You are all familiar with the build, so I will get right to the process. This past February I did a 10 gallon brew day with a friend. We did 2-5 gal batches of my Hefeweizen and then blended them into one batch to control for any mashing differences. I poured 5 gal into the bucket fermenter, and left 5 gal in the flat/open fermenter. I oxygenated each for 30 seconds and then split my yeast (from one starter) into two equal pitches.

Fermentation took off pretty quickly. Both had huge krausens and the traditional bucket had a blowout. After the fermentation completed both were transferred to keg to condition with DME and 2 samples were collected to send for analysis with White Labs analytical lab.

 

[mcbethenstein]

The analysis came back a few days later and I spent many hours tracking down ester names, descriptions and threshold levels. The following slides show the differences in the two batches. The first slide shows the esters that had relatively stable counts (in ppm) as the control. The Green bar on each is the flat/open (coolship style) fermenter. The orange color is the control batch in the plastic bucket. The red bar is the flavor threshold for human detection in beer. And if there is a purple bar, that is the mini ferment data from white labs on WLP380 (available on their website)

The second slide are the esters that there was a difference. Even if slight. I have to say I was expecting a difference in Isoamyl Acetate (the dominant banana note in German Wheats) but it was the same.... BUT The third slide shows that the Ethyl Octanoate was almost 5 TIMES higher than the control, and given that the dominant flavor that WLP380 puts out is apricot (from Ethyl Octanoate) this makes sense. The other striking difference was with Isoamyl Alcohol where the flat/open Hefe was at 106 ppm, the control was 89, and the taste threshold at about 50ppm.

Taste tests concluded that there was a difference. 5 Tasters tried both versions side by side and could tell the difference between the two, however 4 of 5 preferred the traditional bucket version, because it was more "Hefe-like." 1 preferred the more fruity nature of the flat/open.

I think I would like to try this experiment again with WLP300 to try the more traditional strain that most Hefe drinkers are expecting. The Flat/Open fermenter got much better attenuation with a final gravity of 1.006 and dropped clearer, while the bucket attenuated to 1.011 with a slight bit more yeast left in suspension.

 

[tagz]

Wow. Nice work! Very interesting stuff. I know hefeweizens are your thing, but I would love to see a saison version of this experiment. So, the levels were just below the taste threshold, but did you pick up any solvent or acetal in your tasting? Also, which did you prefer?

 

[ArcLight]

I noticed that the open fermentor had much more (by a factor of 10) Acetaldehyde, but it was still below (though near) the detectable threshold. I wonder if conditions were changed a little (slightly less healthy yeast) if the taste threshold would be reached, and the beer not taste as expected?


As for the 5 tasters preferring the control sample - it may be because:
1 - that's the flavor they are used to
2 - the flat fermentor isn't quite to style

Had brewers always used flat fermentors , maybe the tasters would prefer the flat fermented beer, saying the bucket was missing Apricot flavor and didn't taste to style.

I personally am less interested in brewing to style, and more interested in making beer I like.
The style was influenced by technology (or lack thereof). For me, I wouldn't want to be limited by it.

 

[Gavin C]

Great Read. Thank's OP for all the hard work that has gone into this. I trust your speech at the NHC went well. Very nicely documented. Really loving all the pictures illustrating things.

 

[mcbethenstein]

To answer a few questions...
On the acetylaldehyde, I did not detect it, nor was it mentioned by any of the tasters. I did pull an early few bottles of the flat/open Hefe and send them to midwinter competition. It didn't score particularly high, to the judges the banana was too muted, they could not pull out the apricot notes, but none mentioned acetaldehyde, so it was definitely below the threshold of a few trained judges.

ArcLight - to answer all your questions, I think you are right about the tasters preference. It was different, but not so drastically that they couldn't tell it was a Hefe. The yeast health obviously is a factor in this fermenter shape given that the yeast flocculated out faster with the flat/open. I have read/heard that open fermentation yeast will get full and lazy and floc out, but it would result in a stuck fermentation, so as part of my process for this fermenter, the yeast are roused during skimming. To address how I split the starter (question from your PM)... I too was concerned about stratification so I poured out in 3 rounds. Putting the starter back on the stirplate between pours. I hope I got a good split (as close to 50/50) as is humanly possible without starting with lab counted samples. I considered pitching 1 vial into each, with the same manufacture date, but I only had access to 1 vial at the time I conducted the experiment.

My preference was for the flat/open fermented one when I tasted the beers before sending them to analysis, then I preferred the bucket at the time I did the taste testing, afterwards I preferred the flat/open... It really keeps changing. As the beers have aged the differences are smoothing out. The strength of the apricot has subsided (as we know esters are prone to do with time) and the remaining yeast in the control has dropped and the yeast bite that may have been the "Hefe" character that my tasters preferred is deminished as well.... But it may be time for a last taste test before I kick the kegs (each has about a gallon left)

 

[mcbethenstein]

It's application time.... Yesterday I was a bad scientist. I brewed my Hefe again, but made 4 changes! Agh too many! Just kidding. With all my prep for NHC I ran across old notes and some new realizations. I swapped out my bohemian wheat for the rahr red wheat. (I want to see if the rye like creamy flavor translates into my Hefe) Lowered my ferulic acid rest to 104°F (per my reference journal). Pitched WLP300 instead of WLP380 (due to Availability and curiosity), AND here's the big change... Monitored my pH into & out of the kettle and adjusted down. (Referenced in brewing with Wheat... Schneider does this. They feel if wort pH is too high they lose character) I found average into fermenter pH is supposed to be 5.1-5.3. Mine was 5.7 so I adjusted down to 5.07 with lactic acid... A little lower than my 5.1 target, but close. This COULD be the final adjustment that makes my flavors pop. They are there in great balance, but have been muted. My spring water is very high carbonate, and then the RO I sparge with (which I don't adjust) had my into kettle pH at 5.81.... A bit too high. I do adjust pH in the mash, to 5.3.

Fermentation took off this morning. After pitching at 66°F temps rose to 69°F by 11 am and 72°F by tonight. It smells amazing so far. Much clove-ier than my last few batches. And a really healthy fermentation. (Pitch of 8 mil cells/mL) it's starting to produce banana and hints of vanilla. Little to no sulphur. In my research, I found that pitch & oxygen influences the balance of the esters and phenols. And temperature controls the intensity (skewing the esters as you go very high). I've followed this principle since I had a few really great hefes from fellow homebrewers, one fermented at 63° F. So I've tried fermenting at 62-65°, but all my score sheets suggest a higher temp, as the balance is there, but restrained for a Hefe... Hence letting the free rise. View attachment ImageUploadedByHome Brew1434948010.023240.jpg

 

[ArcLight]

>.. Mine was 5.7 so I adjusted down to 5.07 with lactic acid...


1. How long is the Ferulic Acid rest? Does it also lower the pH and by how much?

2. Your mash temperature should theoretically activate Phytase to further acidify your mash.
But I think it takes several hours, so its probably easier adding the lactic acid (or Phosphoric acid - since lactic acid may add a flavor above a certain threshold).

 

[mcbethenstein]

1. Ferulic acid rest is 30 minutes. The minimum needed to see a large jump in Free Ferulic Acid to bump up 4VG. No it does not really acidify the mash. My ferulic acid rest sat at 5.76. Then after infusing my highly carbonate spring water to bring up to sacc rest the mash measured in at 5.89. A bit too high for good extraction. So I adjust downward with Lactic Acid. 6.5 ml brought it to 5.31. I did not check the sparge water, but it is pure RO (guess pH of around 7.0)... And I batch sparge. Into the kettle I was at 5.81. After boiling I was down to 5.7. Hence the adjustment. I wanted to target 5.1-5.2 for my into fermenter pH, and over compensated slightly. I am finding conflicting information about taste threshold of Lactic Acid, but have found at least 3 references that german brewers are adjusting pH into the kettle with wort soured with lactic acid producing bacteria and no residual lactic taste. Schneider Weiss adds wort soured to pH of 3.0 (but the book did not reference how much of the wort that was.) Weyermann claims you can use up to 10% acid malt without tasting it... so that would be equivalent to 1.25 ml/lb grain. At 10.25 lb grain bill, I could add up to 12.8 ml lactic acid without taste implications. With my after boil adjustments, I am right at that threshold....

http://discussions.probrewer.com/showthread.php?6608-Lactic-acid-addition-during-boil

Brukaiser's lactate theshold experiment found that the perceivable threshold is easily over 8-10%, in fact close to an average of 13%, so 8% sauermaltz is not unreasonable. http://braukaiser.com/wiki/index.php?title=Lactate_Taste_Threshold_experiment

 

[orangehero]

How much lactic acid did you use to get it from 5.7 to 5.07? You can always try using phosphoric acid if you are concerned with the flavor of lactic acid.

Your pre-boil pH of 5.81 and post-boil pH of 5.7 both seem a bit high to me. It should be more along the lines of 5.4 - 5.5 into the kettle and drop down 0.1 to 0.3 after boiling. I would maybe look closer at your mash acidification.

Are you also comparing this trial with fermentation in a carboy?

 

[ArcLight]

How much lactic acid did you use to get it from 5.7 to 5.07? You can always try using phosphoric acid if you are concerned with the flavor of lactic acid.

Your pre-boil pH of 5.81 and post-boil pH of 5.7 both seem a bit high to me. It should be more along the lines of 5.4 - 5.5 into the kettle and drop down 0.1 to 0.3 after boiling. I would maybe look closer at your mash acidification.

Are you also comparing this trial with fermentation in a carboy?

She mentioned "highly carbonate spring water".
If the water has a high RA it's going to interfere with the pH drop of the mash.
Hence the need for acidification.

 

[mcbethenstein]

She mentioned "highly carbonate spring water".

If the water has a high RA it's going to interfere with the pH drop of the mash.

Hence the need for acidification.

Correct. Sadly, my yeast accentuated the pH drop during the fermentation as lower pH worts are supposedly prone to doing, so I'm sitting on a Hefe with a finished pH of 3.75. A drop of 1.32, well over the 1 point drop that I read to expect. I'm going to have to change my brewing water. There is WAY to much residual alkalinity, and the buffering action has me using too much Lactic Acid. I tasted my Hefe during the fermentation and it's good. Higher clove levels than I've achieved before, but as a super taster, I can pick out the lactate. I won't be submitting this to competition and I will be figuring out how to adjust the water to get my into fermenter pH closer to 5.3(ish) without excessive Lactic Acid. I need to zero in on that balance between enough acidity to make a flavorful Hefe, but not so much that it is overboard. I really wish I had readings on my last few brews to see where they were into & out of the fermenter.

Sorry for the tangent. This batch is not a side by side experiment. Just documenting putting the flat/open fermenter into practice.

 

[drchris83]

Being in the process of perfecting my Hefe as well (albeit at an earlier stage) I can only commend your effort. Also, if you can get your habds at a bottle of Schneider Weisse, you have their house yeast strain in your hands as well. It is general practice among German home brewers to reculture from unpasteurized bottles of commercially available Weizen. Seeing as you use a very scientific approach, I imagine this to be within your grasp. If you speak any German, I recommend hobbybrauer.de and its vast archives - there is similar research being done there. Also, there have been blind tastings of split batches fermented with different yeast. WLP 300 was never among the favorites, whereas beers fermented with recultured yeast from commercial samples. All of this nonwithstanding, I think it's time for my rectangular lautering vessel to get a second job...

 

[ArcLight]

Correct. Sadly, my yeast accentuated the pH drop during the fermentation as lower pH worts are supposedly prone to doing, so I'm sitting on a Hefe with a finished pH of 3.75. A drop of 1.32, well over the 1 point drop that I read to expect. I'm going to have to change my brewing water. There is WAY to much residual alkalinity, and the buffering action has me using too much Lactic Acid. I tasted my Hefe during the fermentation and it's good. Higher clove levels than I've achieved before, but as a super taster, I can pick out the lactate.

1. (genius idea I admit) Use less Lactic acid.

2. (another genius idea that I'm sure no one ever thought of) Blend your water with a couple of gallons of soft RO water

2. I've never done it, but I'm dying to know how well an long acid rest works.
Let me try some subliminal coaxing -
Do a 4 hour Phytase rest at 95F for 4 hours and post the results
I guarantee it will make a great Hefe. I'll prove it.
Send me a bottle of the beer, and being a "super taster" (I like to taste beer!) myself I'll give you a fair and balanced evaluation

(I wish I had a better palate, I can't taste Diacetyl when others do)

 

[mcbethenstein]

Ok, Here is the latest update. On 6/30/15 I ran a double brew day (night), and brewed my Hefe and a BIAB Wit. I backed WAY off the Lactic acid and used store bought RO water for the majority of my water. (I couldn't pull enough from my filter in time) I mashed in with the Spring water and hit 5.74 pH... just a smidgen under my target, but really close for the ferulic acid rest at 105. Rested about 30 minutes. (my detailed notes are at home, and I am not) Infused to hit 154. Decoction to hit 158-160. I only used RO water after the ferulic acid rest. I did pH adjust for the mash and out of the boil, but it was less Lactic Acid than last time for a total of 6.5mL of Lactic Acid. Into fermenter pH was adjusted down to 5.5. Finishing pH was 3.9. A drop of nearly 1.6, again way higher than expected. I did use the flat/open fermenter and would be curious to do another side by side and see if the pH drop is as high with this yeast in the bucket. (I switched back to WLP380 for this batch). I fermented warm. Pitched at around 68 and let it free rise to 72 at peak fermentation. Fermentation was complete at 3 days. I was in a rush to bottle for competition and bottled at 4.5 days after pitch. I was worried that this was too quick, but my worries were unfounded, as it was at terminal gravity and was relatively clear (yeast had flocked). I sent it to two competitions and am glad to say that I finally broke my dry streak! While I was tinkering with it I had not placed with this Hefe since 2012. I won Gold with this beer yesterday at the 2015 Germanfest Stein Challenge, and won a blue ribbon and was Grand Champion Beer at the Waukesha County Fair (admittedly a VERY small 1st year competition). This beer is the best Hefe that I have produced, and is closest yet to what I have been trying to achieve. At this point the only criticism from the judges was a thiner body than world class examples... but not so thin as to lose many points. I will look into whether just a higher mash temp is needed or if my aggressive fermentation thinned the body as was suggested. I bottled to about 3.5 volumes, and I think that REALLY helps in competition with a hefe. I shall see if the kegged remainder has the same expression as the bottled few... It was kegged with DME and naturally conditioned as ALL Hefes should be.

An update on the previous batch: The over acidified hefe was not thrown. I infused a oak spiral with tequila and then infused that tequila with peaches. Tossed it all in a keg and called it El Hefe Reposado, and served it a local festival. Tequila Barrel Aged Peach Hefe =Huge Hit. And not a loss of beer and ingredients for me.... Those hooligans at Firkin Fest will drink ANYTHING.

 

[bembel]

Greetings from Boston..

I pitched my 15th hefe of the year on Friday ( all slight variations of the basic Bee Cave recipe) trying to hit the clove I so adore in Weihenstephaner and Franziskaner)

I have done decoctions, multi step mashes, low temp, mid temp, multi-temp fermentations using every Torulaspora Delbrueckii variation and still can't nail down the flavors that the commercial hefe gods achieve. So last Friday, I decided to try it open, in a 8 gallon bucket inside my keezer for the first 2-3 days, then I googled Open Fermentation homebrew and found these threads, so I am glad to know I am not the only insane one. Peace at last.

So thinking now that shape is a potential variable, Im looking for a suitable 'coolship' that will fit well inside my keezer, which is only 15.5 inches wide, x 24 long before the hump, so many of the low tote -like tanks don't fit. The fish tank idea is a good one, but hard to lift in, out.

Current batch is 20 hours in and I am about to go home and skim, this one is set at 63 and was pitched at 60 with 3056 in a 1 liter starter.

Happy to collaborate with anyone on anything, just glad that there are others willing to chase this dragon with me.

 

[adamranders]

Hello from next door in Brookfield, this is an awesome thread. Congrats on the wins, and keep it coming, thinking about trying a coolship setup one of these days myself, might have to have a go at this.

 

[mcbethenstein]

Greetings from Boston..

I pitched my 15th hefe of the year on Friday ( all slight variations of the basic Bee Cave recipe) trying to hit the clove I so adore in Weihenstephaner and Franziskaner)

I have done decoctions, multi step mashes, low temp, mid temp, multi-temp fermentations using every Torulaspora Delbrueckii variation and still can't nail down the flavors that the commercial hefe gods achieve. So last Friday, I decided to try it open, in a 8 gallon bucket inside my keezer for the first 2-3 days, then I googled Open Fermentation homebrew and found these threads, so I am glad to know I am not the only insane one. Peace at last.

So thinking now that shape is a potential variable, Im looking for a suitable 'coolship' that will fit well inside my keezer, which is only 15.5 inches wide, x 24 long before the hump, so many of the low tote -like tanks don't fit. The fish tank idea is a good one, but hard to lift in, out.

Current batch is 20 hours in and I am about to go home and skim, this one is set at 63 and was pitched at 60 with 3056 in a 1 liter starter.

Happy to collaborate with anyone on anything, just glad that there are others willing to chase this dragon with me.

Yes, I will collaborate, but know that is a unicorn, not a dragon. lol. J/K

For the Clove, here is the super quick summary of all my research over the last 3 years:

Ferulic acid rest: is a must. Aim for 30 minutes (levels off at 2 hours, but protein degradation may be too high) , and then skip the protein rest. Highest Ferulic Acid release is achieved with a rest at 40C (104F) and a pH of 5.8. (pH of 5.7-6.1 shows very similar ranges). more Free FA (Ferulic Acid) is seen when mash is thicker (I mash in at 0.6 qt./lb...its the lowest I can go and have the grain actually get wet!) and a continuously stirred mash will see up to a 45% increase in Free FA.

Mash: Higher thickness must be continued throughout Mash (my main mash is 1.3 qt/lb...most software is set to mash in at 1.5 qt./lb.) A thicker mash will show more cloves, a thinner mash (over 1.5 qt./lb.) will favor the esters and sour notes in the beer.
Thicker mouthfeel will accentuate the cloves as well. (main mash temp may need to be increased.) Skipping the protein rest will help with the body... enough protein is broken down during the FA rest. I decoct to get an increased maltiness that will favor cloves, and increase my efficiency, but there are examples of non-decocted brews that show huge cloves.

Grain bill: choose your grains so that they give a full mouthfeel. See my malt comparison thread if you want to see how I found the best grains for my hefe.

Yeast: Your choice. WLP300 is finicky, but can be higher cloves than 380 if done right, otherwise will be all banana and sulphur. 380 is consistently high on cloves, but the ester expression is more to apricot/stone fruit than banana.

Pitch Rate: Aim to get 6-8 million cells per mL of wort. For my last 5.5 gallon batch that was 2 really fresh tubes. Anything too much lower will increase the esters and they will overpower the cloves. Anything drastically too high and the yeast will not need to reproduce and your flavor will be weak overall.

Oxygen: Give the yeast plenty of Oxygen. I go with 1 minute of pure O2. low oxygen favors ester production and that can overpower the clove.

Starter?: I recently came to the realization that when I make a starter to get to my desired pitch rate that I have great clove smell in the starter and then the finished beer seems low in clove. I know that clove is produced during the replication and lag phases, so from now on I want that to happen in my beer, not in the pour off from my starter. I will purchase enough tubes to get my desired pitch.

Temperature: Uncontrolled (non-deliberate) temperature can really screw up your beer. But so can going too low. Temperature just seems to increase the profile that you have already set the stage for by your recipe, mash profile and yeast factors. I have had plenty of hugely clove beers fermented at 68. Like I just mentioned my last one was fermented at 68-72, and its the cloviest one yet... (probably because of my mash temp change, and trying to stir often to increase free FA) A lot of my 62-63F fermented beers just seemed restrained at best when fresh and then almost lager-ish after sitting in the keg a while. Don't go too high though, excessive heat will increase esters. (think 73F+)

Bottling: Is a must for competition (you can't get a high enough CO2 bottling from keg), kegged versions should be naturally conditioned. a few references I found noted that the second fermentation in bottle or keg) increased cloves again.

Open fermentation: See above thread.

 

[ArcLight]

If one ends up with a beer that's too acidic, can't you add a little Sodium Bicarbonate or Calcium Carbonate? At least enough to raise the pH a little.

 

[mcbethenstein]

If one ends up with a beer that's too acidic, can't you add a little Sodium Bicarbonate or Calcium Carbonate? At least enough to raise the pH a little.

I believe so. But the Lactic Acid will still leave lactate behind, which has a distinctive taste. That's what they were testing for in brukaisers experiment. Once over the taste threshold it can not be removed or neutralized, but perhaps covered up. If too acidic from the yeast and not lactic acid, I believe the carbonates will work. Wine makers sometimes resort to this. I have no experience with dosage though. I went with embracing the acidity/tartness and added fruit & tequila. At the festival, I could not tell that it was too acidic at all. The one that finished at 3.9 was pleasantly tart, but mostly a clove and banana punch, all within expectations for s Hefe. It really is pretty perfect for a homebrew Hefe. I think I am done tinkering. For now.

 

[bembel]

Fascinating info on the long FA rest and the thick mash helping in that regard as well

Confused by your advice on pitch rate, I too, have had some starters that after crashing smelled like a Turkish Spice market in clove intensity but the beer they made did not come close, I have read that the phenols are produced during reproduction, but what is the difference between pitching 2 fresh tubes or packs to get desired count vs using a yeast calculator to grow one tube to the same count? I can see that there is probably a much larger margin of error in making a precise starter since they all tell you amounts in 500ml increments ( in terms of cells produced). Or is there another reason? Maybe I need a different starter calculator that would tell me how exactly much of a specific gravity wort to start with, time and temp to grow, in order to get the cell count I desire, I use the Homebrew Dad on-line version, it's not that precise )

Had to LAUGH about the Peach Tequila Hefe, my 13th batch went sour (likely since I added a second yeast starter after it halted fermentation at 1025 and held in in primary for 4 weeks), but half of that is now a lovely sour Apricot and the the other is sour cherry. My latest batch with 380 ended up pretty bland, and half of that is now Pink Grapefruit Hefe lightly dry hopped with some Galaxy and and the other is a Mango dry hopped with Azacca, both which come out insanely yummy. Mistakes can be tasty too!

 

[mcbethenstein]

I think there is a high margin of error in starters. Mine is on a stirplate and although the Brewers friend calculator can account for that I think my starters are ending up with a higher cell count than expected. If the count is too high, little replication happens, oxygen levels are still high and then ester & phenol production will be minimal and the beer will taste clean. I got the 6-8 mil cell per mL from the brewing with wheat and classic german wheat book. There are a handful of references to pitch rate. When I attended Neva Parker's talk at Northern Brewer I learned a lot about the life cycle of this yeast. She suggested pitching up to 18 mil cells per mL to maximize clove, but I later found references that you still need replication to happen for clove production. So phenols peak production is during reproduction and ester peak production is at the start of fermentation. Oxygen levels at those times control the intensity of each. If oxygen is depleted from reproduction the yeast become stressed and throw off more esters. Balancing pitch rate, oxygen and temperature is almost a difficult as explaining that balance! My experience with my starters is just that. My experience. In theory if your starter was super precise (and perhaps you could do a laboratory cell count on it) you could be assured of your pitch rate and feel confident pitching the correct amount. For now I'm going to just spend the extra $7 and not worry... But that's going to get shot to hell in a few months when the pure pitch packets make it down to the Hefe yeasts... As I heard on their tour that viability is much better with the pure pitch than the tubes, and the online calculators will be wrong (underestimating viable cell count)

 

[bembel]

Ok, Here is the latest update. On 6/30/15 I ran a double brew day (night), and brewed my Hefe and a BIAB Wit. I backed WAY off the Lactic acid and used store bought RO water for the majority of my water. (I couldn't pull enough from my filter in time) I mashed in with the Spring water and hit 5.74 pH... just a smidgen under my target, but really close for the ferulic acid rest at 105. Rested about 30 minutes. (my detailed notes are at home, and I am not) Infused to hit 154. Decoction to hit 158-160. I only used RO water after the ferulic acid rest. I did pH adjust for the mash and out of the boil, but it was less Lactic Acid than last time for a total of 6.5mL of Lactic Acid. Into fermenter pH was adjusted down to 5.5. Finishing pH was 3.9. A drop of nearly 1.6, again way higher than expected. I did use the flat/open fermenter and would be curious to do another side by side and see if the pH drop is as high with this yeast in the bucket. (I switched back to WLP380 for this batch). I fermented warm. Pitched at around 68 and let it free rise to 72 at peak fermentation. Fermentation was complete at 3 days. I was in a rush to bottle for competition and bottled at 4.5 days after pitch. I was worried that this was too quick, but my worries were unfounded, as it was at terminal gravity and was relatively clear (yeast had flocked). I sent it to two competitions and am glad to say that I finally broke my dry streak! While I was tinkering with it I had not placed with this Hefe since 2012. I won Gold with this beer yesterday at the 2015 Germanfest Stein Challenge, and won a blue ribbon and was Grand Champion Beer at the Waukesha County Fair (admittedly a VERY small 1st year competition). This beer is the best Hefe that I have produced, and is closest yet to what I have been trying to achieve. At this point the only criticism from the judges was a thiner body than world class examples... but not so thin as to lose many points. I will look into whether just a higher mash temp is needed or if my aggressive fermentation thinned the body as was suggested. I bottled to about 3.5 volumes, and I think that REALLY helps in competition with a hefe. I shall see if the kegged remainder has the same expression as the bottled few... It was kegged with DME and naturally conditioned as ALL Hefes should be.

An update on the previous batch: The over acidified hefe was not thrown. I infused a oak spiral with tequila and then infused that tequila with peaches. Tossed it all in a keg and called it El Hefe Reposado, and served it a local festival. Tequila Barrel Aged Peach Hefe =Huge Hit. And not a loss of beer and ingredients for me.... Those hooligans at Firkin Fest will drink ANYTHING.

I think there is a high margin of error in starters. Mine is on a stirplate and although the Brewers friend calculator can account for that I think my starters are ending up with a higher cell count than expected. If the count is too high, little replication happens, oxygen levels are still high and then ester & phenol production will be minimal and the beer will taste clean. I got the 6-8 mil cell per mL from the brewing with wheat and classic german wheat book. There are a handful of references to pitch rate. When I attended Neva Parker's talk at Northern Brewer I learned a lot about the life cycle of this yeast. She suggested pitching up to 18 mil cells per mL to maximize clove, but I later found references that you still need replication to happen for clove production. So phenols peak production is during reproduction and ester peak production is at the start of fermentation. Oxygen levels at those times control the intensity of each. If oxygen is depleted from reproduction the yeast become stressed and throw off more esters. Balancing pitch rate, oxygen and temperature is almost a difficult as explaining that balance! My experience with my starters is just that. My experience. In theory if your starter was super precise (and perhaps you could do a laboratory cell count on it) you could be assured of your pitch rate and feel confident pitching the correct amount. For now I'm going to just spend the extra $7 and not worry... But that's going to get shot to hell in a few months when the pure pitch packets make it down to the Hefe yeasts... As I heard on their tour that viability is much better with the pure pitch than the tubes, and the online calculators will be wrong (underestimating viable cell count)

What is the OG of the wort that the 6-8 mill/ml is calculated on? or is that the rate per degree plato?

 

[mcbethenstein]

It is calculated on total volume, not degrees Plato. If I factor in starting gravity it comes to .5-.6 million cells/mL/°P. The references in the books don't get that specific to gravity. Just pitch size based on volume.

 

[bembel]

Hi just read through your full post, CONGRATS on the latest medals! For all the German completion in your neck of the woods that’s huge! OK, now I REALLY want details from your brew log. Would you be willing to share (I promise not to enter any competitions in Wisconsin! But seriously, that the most Germanic part of the country and to win with what must be stiff competition is really an accomplishment.
My first competition entry was my 8th hefe brew, I thought it was pretty bland, not as much of the clove I wanted, but I filtered it and kegged it and counter pressure filled a few bottles after a HEAVY force carb at about 30 PSI and entered it as a Kristal Weizen It took 1st in category ( out of only 12 other entries, like getting to first base on a walk) but somehow that beer managed 2nd best in show out of 350 other, much better beers, however that was in Boston, and I think it was the first time anyone had even seen a Kristal Weizen, so I lucked out at the ‘new kid’ and the BCJP guidelines that describe Kristal as muted versions of their hefe brethren.

After reading your info on ph, looks like i’m going to need a better ph meter, what do you use by the way? The good ones seem to also require a lot of upkeep and care.

3 days into my first open ferment at 63-64F gravity dropped from 1052 to 1022 and the kreusen is gone, I never got the thick, bubbly creamy top, just white foam with some hop particles making it lightly brown, but I used 3056 not 3068, wondering if that’s normal, I also got practically no clove or banana aroma, more caramel. racked to a carboy yesterday and left it at 70 to finish, I have yet to have a brew drop below 1020, even though I aerate using pure O2 and pitched a 1 liter starter.