Open fermentation in a plastic DIY Coolship

[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.