Preparing Fruit for Secondary

[brandonnys]

I have a couple pounds of blackberry puree that I prepared from fresh picked blackberries. I basically picked them, put them in a Vitamix, and then strained the fruit through a strainer covered in cheesecloth. The resulting liquid is viscous and smooth.

At this point I want to add it to a blonde that I have sitting in secondary. My question is properly preparing the fruit for introduction into the beer. I don't want to lose a bunch of the volatile aromas from the blackberries, so I'm not inclined to do a double-boiler to pasteurize them, but I also don't want it to go wild and not be a blonde. Is there a safe way to pasteurize this puree without degrading it too much?

My thoughts are:

1. Use a sous vide machine and hold the fruit at 180deg for 15 minutes inside a food saver bag (I have a sous vide machine).

2. Put it in a mason jar and pressure can it (I don't have a pressure cooker, so I'd have to get one).

Aside from those two options, I don't know what to do.

 

[IslandLizard]

I think when you look around (search) the consensus is NOT to heat or boil your fruit. It changes the flavor profile drastically, making it taste like, well, cooked fruit.

The acidity of the juice helps preservation. Deep freezing the juice for a few days, or a few repeated freeze/defrost cycles should kill most microorganisms left, but possibly not all. Mold spores are always the hardiest, but depending on your process, they're usually not an issue.

UV pasteurization is probably the best safeguard, but cannot be done without specialized equipment, and may be overkill, so to speak. Flash pasteurization maybe the next best option, but again, we don't have that equipment at home either, and the heat does change things.

 

[brandonnys]

My assumption is that the fruit would start to taste more like preserves and less like the fresh fruit. Is this the main concern? Or is it a fructose caramelization thing? I'm hoping that keeping the fruit in a sealed environment that I can minimize the "change" as much as possible while making sure to kill any errant yeast/bugs/bacteria/whatever that is living in the puree.

I did freeze the berries immediately after processing them into the puree.

I've poked around at various threads, and I noticed a number of people saying "Don't heat it" because it "changes", but I was hoping for a little more clarity as to what that would be. Possibly the pectin is the concern?

 

[Weezy]

The pros don't even wash them.

 

[brandonnys]

The pros don't even wash them.

Interesting. I was under the assumption that pros, when just imparting a fruit flavor and aroma in a beer, relied on brew-ready extracts that had previously been pasteurized because they would not cause spontaneous or unwanted fermentation from wild yeast.

Honestly, introducing the fruit as-is given what I've said above, what's the likelihood that a wild yeast strain would have survived and will make it in the beer? I really don't want this thing to turn into a Lindemans blackberry lambic, just a nice blackberry blonde.

 

[Weezy]

Interesting. I was under the assumption that pros, when just imparting a fruit flavor and aroma in a beer, relied on brew-ready extracts that had previously been pasteurized because they would not cause spontaneous or unwanted fermentation from wild yeast.

Honestly, introducing the fruit as-is given what I've said above, what's the likelihood that a wild yeast strain would have survived and will make it in the beer? I really don't want this thing to turn into a Lindemans blackberry lambic, just a nice blackberry blonde.

The big pros use extracts and purees. The small micros that make the really special, handcrafted ales that we gush about, get local fruit from local farmers and cut up the stone fruits or macerate the others and it goes in barrels or fermenters like that.

I wouldn't worry about blackberry lambic unless you're​ planning on cellaring this for 5 years. There's not enough cells there.

 

[Calder]

Thaw the juice, add a campden tablet, and 24 hours later, add to beer.

Might find more on this in the wine forum.

I usually heat my fruit to 150 and hold for 20 minutes, but you don't want to heat it.

 

[Jaxmickey]

I always freeze my fruit for 2 weeks, then thaw and puree under sanitized conditions. I think Calder is on the right track. I'm not sure what happens chemically in the heating process, but have headed the warnings of the other threads as well.

 

[ShagmeisterBrewing]

I generally mash up fruit in a sanitized ziploc bag, freeze it for a few days, then thaw and add to secondary.

I have had good results when using this method.

 

[ShareBrewing]

Freezing is probably the easiest and best way to go here. Not sure what a full campden tablet (potassium metabisulfate) would do in that small amount of juice. It'd kill everything for sure, but would it carry over at all into the fermentor and begin to inhibit fermentation by the yeast?

I always freeze in a sanitized bag/container for a few days/weeks, let thaw, crush, and repeat. That ensures the cell walls of the fruit are really broken down and give great flavor. This always works for me.