Fermentation schedule for sour ale

[demetman]

Hello, I am planning on brewing a sour beer that I pulled from a current read "Homebrew All-Stars". The recipe is a derivitive of Mike Tonsmeire's solera project called Perpetuum Sour. I've changed the recipe slightly to occomodate the ingredients I have. I'll be fermenting with TYB House Sour Blend.

Do you guys reccomend racking to secondary for extended aging after primary fermentation or do you leave your sours in primary until terminal gravity is achieved and the level of complexity is to your liking? The clean ales that I have brewed that require extended aging have all been racked to secondary to avoid autolysis and off flavors. Here is the recipe I am planning to brew

5.5 gal, 1.058 OG, 10IBUs
5.5# pilsner
5# pale malt
1# flaked oats
1# torrified wheat
.75# wheat malt

mash at 156 for 90 min, williamette and cascade at 60min, pitch TYB House Sour Blend 2L starter and ferment at 70F for several months or desired level of sourness and funk is achieved.

Thank you for any feedback and insight, as I am just starting to brew with wild cultures.

 

[RPh_Guy]

I'm interested what people say as well.

Looks like you're going for less sour, more Brett funk, yes?

Using a secondary is not necessary (see http://www.milkthefunk.com/wiki/Mixed_Fermentation#Secondary_Fermentation ).
However if you prefer, I think it'd be safe to rack at the same time you normally would for aging (after 2-6 weeks?). A small amount of Brett will be enough to keep going and the Sacc and LAB should definitely be done by that point.

 

[radwizard]

Brett should clean up autolysis of flavors, but many brewers still rack off the trub. Some do, some don't. In Tonsmeire's method, from the book, he does rack to a secondary. If you have co2, it is wise to purge the carboy and head space. If you don't, you should at least minimize head space (like all the way up to the neck of the carboy).
Personally I do both methods, depending on what I have going on, I don't really see a difference after the long fermentation, there are lots of things going on during this time.

I would go for far less ibus then 10 for your first pitch of that yeast. You'll get something funky and tasty as is, but I would recommend trying to promote more acidity. Most peoples first sour attempts turn out pretty low on the acidity level. I seriously doubt youll get to much acidity on this yeasts first preformance, but if you want to tame it, it is much easier to blend out then wait for another beer to produce enough acids to blend. If it was me I would aim for 3 ibus or so. Its a personal choice, but ibus will greatly factor how sour your beer gets.

The times I have racked I did so at about 3 weeks.

 

[demetman]

My intentions are to promote acidity and maximize the souring potential of the lacto in the blend. I will certainly lower IBUs to around 3. I'll rack to secondary and purge as suggested. Just curious as to the primary purpose of torrified wheat in this recipe? Possibly additional starch for the brett to munch on? Never used unmalted grain before. Again, thanks for the info. I'm sure I'll be back for more

 

[RPh_Guy]

My intentions are to promote acidity and maximize the souring potential of the lacto in the blend. I will certainly lower IBUs to around 3. I'll rack to secondary and purge as suggested. Just curious as to the primary purpose of torrified wheat in this recipe? Possibly additional starch for the brett to munch on? Never used unmalted grain before. Again, thanks for the info. I'm sure I'll be back for more

With a blend like that all pitched at the same time it's less easy to predictably promote certain organisms, however Lactobacilli generally like warm temperature and hate hops. 70F is probably too cool to promote their growth (based on the info on that blend from TYB)... At least the starter should be a bit warmer.

Buffering your starter with calcium carbonate with drastically improve cell counts as well!

...I'd guess the torrified wheat is for additional body and head retention. I'm not sure.

 

[demetman]

With a blend like that all pitched at the same time it's less easy to predictably promote certain organisms, however Lactobacilli generally like warm temperature and hate hops. 70F is probably too cool to promote their growth (based on the info on that blend from TYB)... At least the starter should be a bit warmer.

Does the lacto promote sourness only during primary fermentation or does it continue to sour afterwards as well? I know the brett is a slow developer and will take time. I wanted to ferment in a dedicated "bugs" closet which is house ambient temp(71-74F). I'm brewing quite frequently and didn't want to tie up my chamber for a long period of time. Could I ferment at 70 for a few days then ramp up the temp to 78-80F for 2 weeks, rack to secondary and put it in the closet to age for months?

Buffering your starter with calcium carbonate with drastically improve cell counts as well!

What exactly does chalk do to increase cell count in a starter? I use Light DME and only add yeast nutrient


...I'd guess the torrified wheat is for additional body and head retention. I'm not sure.

Thanks

 

[RPh_Guy]

Does the lacto promote sourness only during primary fermentation or does it continue to sour afterwards as well? I know the brett is a slow developer and will take time. I wanted to ferment in a dedicated "bugs" closet which is house ambient temp(71-74F). I'm brewing quite frequently and didn't want to tie up my chamber for a long period of time. Could I ferment at 70 for a few days then ramp up the temp to 78-80F for 2 weeks, rack to secondary and put it in the closet to age for months?

LAB (lactic acid bacteria -- the Lacto and Pedio) will generally stop producing acid when the pH reaches a certain threshold OR when all the sugar is consumed.

However, their rate of growth and metabolism is also highly dependent on temperature. Low temperature (e.g. 70F) favors the yeast resulting is less souring effect from LAB. Sacc will consume most of the sugars in a matter of days as per usual. There will still be some sugars left until the Brett species make their way through them over the following weeks to months.

For more sourness with this blend TYB suggests 70-72F for a few days (to prevent major off-flavors during peak Sacc fermentation I presume) followed by 75-80F for a few days (at least 48-72 hours should be adequate in my estimation).
Keeping the starter around 75F I suspect would also promote sourness by increasing your initial LAB cell counts.

So, yes, what you described should be perfect although you probably won't need to keep it above 75F for quite so long. If you have a particular pH goal I'd recommend monitoring pH and then bringing the temp back down when you reach it.

What exactly does chalk do to increase cell count in a starter? I use Light DME and only add yeast nutrient

As I mentioned above, LAB growth will stop when the pH decreases to a certain threshold. CaCO3 buffers (absorbs the acid), helping to maintain a high pH. The longer we keep the pH high, the longer the LAB with grow, increasing cell count.

This is not fully necessary, but is certainly helpful if you want a more sour beer. I like very sour beers, so this is what I'd do.

 

[demetman]

makes sense, thanks RPH Guy. I'm a process guy, so I like to have everything planned out before diving in. Just a couple more questions. When you use CaCo3 to buffer ph in your starters how do you determine the amount needed and do you check ph of your starters? I usually use lime for increasing ph when needed in the mash. I do have chalk, just never used it. I use beersmith and just started using bru'n water. I don't have a target ph. I was going to let it go and see what happens. What ph range would you recommend I target?

 

[RPh_Guy]

These two resources describe LAB starters in detail:
http://sourbeerblog.com/lactobacillus-2-0-advanced-techniques-for-fast-souring-beer/
http://www.milkthefunk.com/wiki/Lactobacillus#Starters_and_Pitching_Rate
Both recommend CaCO3 20g/L

CaCO3 is ideal because it doesn't dissolve into solution so you can decant the solution containing your bugs into the wort, leaving behind almost all of the CaCO3.

There is no reason to check the starter pH.

As for target beer pH...

3.6 mildly sour
3.5 semi-sour
3.4 getting there
3.3 you got to like sours to be here
3.2 you got to LOVE sours to be here

Personally I go toward 3.2 - 3.3.
FYI, pH is a surrogate measurement for sour taste. Titratable Acidity is a better measurement to actually quantify the amount of sour taste if you want to get a kit to measure it (I don't).

EDIT:
Uh one more thing about pH. Letting it go is fine; you don't NEED to control it. Only if you want to reach a particular sourness or don't want it getting too sour. You can always blend it later though if it's not where you want it.
Also, TYB doesn't say exactly what pH level this blend can achieve.

 

[demetman]

Thought I'd update this thread. Brewed on 10/23.OG 1.056 3IBU. Cooled wort to 68F, pitched yeast blend, solid activity after 4hrs. 10/25 allowed temp to ramp up to 73F and held for 5 weeks. I racked beer to secondary and purged with O2 today. Gravity was 1.004. Flavor was mildly/med tartness with lite notes of pineapple and tropical fruit. Very nice flavor at this point. PH was at 3.56 at 70F. I am planning to age for 2 months at room temp, then check gravity and level of acidity. I was thinking of dry hopping with 2oz Hallateau Blanc then bottle. Thanks for all the help with my first mixed culture sour!