Effect of FG on souring

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

cactusgarrett

Supporting Member
HBT Supporter
Joined
Apr 8, 2008
Messages
2,314
Reaction score
895
Location
Madison, WI
Pardon the ignorance - new to the sour topic.

I've got a Rodenbach clone souring, and I was wondering something. I based the recipe off Jamil's, which is based on brewing a batch, then souring it with the Wyeast Roeselare blend. He stresses that he targets the initial fermentation to end around 1.020 (via a larger-than-usual amount of unfermentables) in order for the bugs to funk up the rest down to 1.008-ish.

Since i typically get a lot better attenuation than what yeast packs state (maybe my starters are too good?), i ended up getting 1.012 prior to adding the Roeselare blend. Since the bugs will be starting with a lower gravity than originally intended, does this mean my final product will be less sour than if it were to have started around 1.020?

Does the general rule-of-thumb "the higher the gravity, the funkier it gets?" actually apply?
 
In my experience taking the route that Jamil suggests never results in a very sour beer, UNLESS, you can age it in a barrel, fermenting in carboys as most seem to do this method produces a kind of blah beer (at least to my palate) Jamil does say he prefers beers that are only slightly acidic though

1012 is a bit low, I might suggest adding some maltodextrin to the beer, and this is infact something I generally suggest doing on a first pitching of a lambic pack anyway, as the first go around tends to be a bit tame, by adding the malto you ensure there is plenty of food to grow up the populations of pedio and brett among others

as to your ROT, I would say that yes in general the more food for the bugs the more sour/funky it will get,

If I were you I would

1. Add some maltodextrin to give the bugs a lot to work with
2. Add the dregs of several sour beers to improve the microbial diversity in the beer
- Ive had particular luck with JP especially calabaza blanca, and with Girardin, as both tend to be a bit younger than others, Cantillon etc tend to have a bit more age and when Ive cultured them up provide more funk than sour, which is still good to have though
3. put an oak dowl thru the carboy stopper to allow some O2 in, brett work much better with small amounts of oxygen, it is a careful balance though, as too much and youll get ethyl acetate
 
Predicting the final gravity for sour beers in very difficult, but they aren't going to eat a certain number of points, they'll just keep working until they eat all they can (based on mash profile, malts, nutrients, temperature etc...).

Doing Jamil's Flanders Red, even getting it to stop above 1.020, I still didn't get much sourness. I've found that I need to pitch the additional microbes in primary along with the yeast to get as much sourness as a commercial Flanders Red (Lambic etc...). If in a year it isn't sour enough you should consider feeding the bugs some additional sugars, light malt extract, malto-dextrin, or fruit would all be options. Adding the bottle dregs from a bottle or two of unpasteurized sour beer is another great idea, those commercial bugs tend to be more aggressive than the cultures you buy.

You might consider checking your thermometer to make sure you are mashing at the right temperature. That said those stated ranges are based on a "control" wort, so if you tend to use less crystal and mash at a lower temp you will always get lower FGs than the yeast attenuation numbers predicts.

Hope that helps, welcome to sours.
 
We are really starting to sound the same, creepy.
 
I think the final gravity is also a function of which bugs are present, and the percentage of simple sugars. Normally Brett alone doesn't super attenuate, nor does Brett + Lacto, or Lacto alone, or Sacc alone. Add some simple sugars, like fruit, then you'll see a nice gravity drop. Also, I think when you add pedio, it releases an enzyme or something, that breaks down the sugar for Brett to eat allowing it to super-attenuate. I think it also matters when you pitch the Brett. Pitching when simple sugars are available, causes Sacc to stay in simple-sugar mode, and less likely to eat longer chain sugars. I was thinking something similar might happen to Brett.
 
Thanks for all the great info, guys. ryane, with your #3, do you put the dowel all the way down into the beer, or just let it suspend in the headspace of the carboy? I intended on oaking this, so i'm just wondering if any type of dowel will do, or if since it's going to be the oak source i have to put some thought into finding the right one.
 
Also, for a five gallon batch I plan on aging for a year, in addition to dregs, how much malto-dextrine do you guys recommend to add, and via what procedure?
 
Ive done both ways, and I really cant tell a difference, although if the oak stays dry it will let in more O2, so youll have to be a bit more careful to watch for the pellicle dropping in that case

for the malto, id go with ~1# for 5gal, and would dissolve it in as little water as you could and add that to the carboy
 
Cool - thanks. So, since i was going to add oak in the first place, i'll do the dowel-thru-the-stopper method using a dowel from Home Depot, and actually toast the dowel myself and submerge it in the beer. Hopefully this will produce the barrel-aged flavor i was originally intending with the Rodenbach clone in the first place.

This is turning out to be more complex (although not a bad thing) than i had orginally thought it would be.
 
...youll have to be a bit more careful to watch for the pellicle dropping in that case

I'm starting to see this in various threads. Why is it important to avoild a premature pellicle drop? I see a lot of people talking about avoiding a drop by not moving their carboy, etc. I was of the understanding that the pellicle, as far as brewing goes, doesn't serve a purpose (i know scientifically it's to provide a barrier from oxygen, though).
 
if the pellicle drops because it is agitated and it doesnt reform, yet you are letting O2 get into the beer, youll end up with nasty flavors like ethyl acetate ie nail polish remover
 
if the pellicle drops because it is agitated and it doesnt reform, yet you are letting O2 get into the beer, youll end up with nasty flavors like ethyl acetate ie nail polish remover

Only if you have air/oxygen in the headspace. I've never had an issue with dropped pellicles when I'm aging a beer in a carboy or better bottle with an airlock.
 
that is the catch though, I generally use a dowel or if I use an airlock it always runs dry, as long as I dont move the beer its fine, although you tasted how nasty a batch can be (my Flanders Red) when the pellice drops but O2 still gets in
 
Even the dowel doesn't simulate a full barrel in how much O2 can move into the headspace. I'd almost rather leave some loose foil over the carboy neck and let the pellicle do its job.
 
Even the dowel doesn't simulate a full barrel in how much O2 can move into the headspace. I'd almost rather leave some loose foil over the carboy neck and let the pellicle do its job.

Waaaaaaaaay too much oxygen will get in and you'll have 5 gallons of vinegar after a year.
 
Thanks for all the info, again, guys. I ended up adding the malto-dextrine, then adding a self-toasting an oak dowel a couple days after. There didn't seem to me much of an effect from the malto-dextrine addition, but a day after the dowel was added, i started to get some head-space scuzz (sorry for the chitty phone-camera quality). Praise be to Oxygen!

Hougenbach.JPG
 
Back
Top