Fruit and Brettanomyces, how long is too long?

[julioohara]

Hello fellow brewers,
I am planning a recipe for a Baltic Porter or Robust Porter (I have not yet build up a grain bill, but I intend to mash in at the best alpha amylase activity 158-161ish) I plan on fermenting it with a London Ale yeast strain for two-three weeks for byproduct clean up, then racking it onto a secondary fermentor with the addition of rasberries (fresh, frozen then slightly pureed, then sterilized with sulfite) and a culture of Brettanomyces bruxellensis for a slight but noticible "leather like barnyard funk." My considered options are:

1.) Leave in secondary for about 3-6 months (in fruit pulp) or longer until pellicle drops.

2.) Ferment in secondary a couple of weeks, then rack into another carboy and let it age (taking care not to introduce O2 into the beer by all means)

There is another blog of some brewer fermenting Brett with fruit for 3 months, however since it likes to take its time in fermenting I do not know how long is too long for it to be sitting on fruit... Any suggestions or experience?

 

[loftybrewer]

There's a lot of info in general throughout, but at about 18 minutes he starts to talk about fruit and timing. He says they do 6-12 months in oak for extraction but some belgian brewers transfer it to stainless for 12 weeks and get all the extraction they need from the fruit.

 

[julioohara]

Awesome! Thank you very much, I had no idea of this video :-D

 

[jhay_x7]

If it were me, I would do two things:

Don't worry about racking to secondary if you are adding Brett; it will keep the sacch from autolysis by consuming the dead yeast cells. I would rack to secondary after you are finished aging on fruit to help clear the beer out.

I would be hesitant to add sulfite to the fruit puree. There should be enough alcohol in the beer and in combination with the Brett, it should keep things in check. For insurance, add an ounce or two of vodka to your puree and stir it up good, that should kill anything and you are then adding more alcohol to your beer!

One last thing, you might have an issue with pectin haze if you add the puree mixture into the beer. You should be able to combat that with a pectin enzyme or just make the beer dark enough so no one notices

One more last thing... I like to add fruit in my sours/brett beers as soon as possible to develop complex flavors. Over time, especially when aging with Brett, the fruit character can drop out so be sure to taste the beer at least once a month and if you think the Brett character is where you like it but the fruit character has dissipated, just add more fruit and let it sit for a few weeks more.

 

[Calder]

The fruit will already be sanitized. Freezing the fruit will kill almost anything that might be in it.

Freezing also breaks down the fruit, such that there is no need to puree it. I generally let it warm up a little and then mash it with a sanitized masher. No need to add any sulfates.

 

[TNGabe]

The fruit will already be sanitized. Freezing the fruit will kill almost anything that might be in it.

Freezing also breaks down the fruit, such that there is no need to puree it. I generally let it warm up a little and then mash it with a sanitized masher. No need to add any sulfates.

Freezing may kill some cells, but it doesn't come close to sanitizing or pasteurizing fruit.

 

[julioohara]

If it were me, I would do two things:

Don't worry about racking to secondary if you are adding Brett; it will keep the sacch from autolysis by consuming the dead yeast cells. I would rack to secondary after you are finished aging on fruit to help clear the beer out.

I would be hesitant to add sulfite to the fruit puree. There should be enough alcohol in the beer and in combination with the Brett, it should keep things in check. For insurance, add an ounce or two of vodka to your puree and stir it up good, that should kill anything and you are then adding more alcohol to your beer!

One last thing, you might have an issue with pectin haze if you add the puree mixture into the beer. You should be able to combat that with a pectin enzyme or just make the beer dark enough so no one notices

One more last thing... I like to add fruit in my sours/brett beers as soon as possible to develop complex flavors. Over time, especially when aging with Brett, the fruit character can drop out so be sure to taste the beer at least once a month and if you think the Brett character is where you like it but the fruit character has dissipated, just add more fruit and let it sit for a few weeks more.

Sounds terrific! I could use a bit of whiskey too to give it a complex flavor! btw, how do you stir in pectin enzyme onto the beer and at what time of the fermentation is it added? I'm assuming the alcohol in beer will kill any bacteria on it, and I definetely cant boil it because the heat will denature the enzyme, so how do you use it jhay?

 

[julioohara]

I was thinking of freezing the fruit to release its natural flavors and juices (becomes more accessible) and to stun any bacteria and wild yeast in the fruit, that way I could finish them off with campden tablet sterilization, or maybe they will be so stunned that the actual alcohol and yeast/brett abundance will prevent their growth, I'll experiment and have fun with this for sure...