Made it: Banana Beer chapter 2

My first stab at banana beer was going pretty well. I got good fermentation, I hadn't lost much liquid in the filtration process, I had no obvious sign of contamination from my post-ferment filtration.

But then Whitney's cousin sent me her sous vide coooker. With that, I could precisely control the "mash" temperature. I also wanted to see if adding pectic enzymes would make it easier to filter.

I had a good control experiment planned where I'd split the batch in half and do half with enzymes and half without. But then I got distracted and did them both the same way. Oh well. I'll just have to do a third round without the enzymes and compare.

I should say without external enzymes. Bananas have amylase of their own, and I think pectic enzymes too.

Later, I went back and tried it without barley or external enzymes. It was a near-total fail, I didn't get anything you'd call juice, just two thicknesses of mush. I couldn't get a brix or gravity reading.

Anywoo, for the real deal, I mashed up 868 grams of plantains and 1,354 grams of bananas with a potato masher. I should have blended, but I didn't want to destroy the natural enzymes. To that I added 60 mL filtered water, 80 g 2-row pale malt, and a 1/2 tsp each of pectic enzyme blend and alpha-amylase.

I added the malt, the barley, to get it's beta-amylase. Beta-amylase lops sugars off the ends of starch chains, whereas alpha-amylase cuts starch chains at random. I wanted to destroy as much of the structure of the fruit pulp as possible and maximize the production of fermentable sugars, so I used both. I figure a little barley flavor won't hurt the taste.

My starting pH was 5.8, which seemed fine. I placed both sections in 1-gal ziplock freezer bags and set the sous vide machine to 104 F. There it sat for 2.5 hours. This was the pectin rest, as that's the temperature recommended for pectin degradation by some online guides and this paper I found about extracting bananas with these enzymes to make banana wine (https://doi.org/10.1111/j.1745-4530.2007.00152.x). I used lower temperatures but longer times than in a beer mashing, figuring the lower mobility and minimal stirring would slow things down.

Twice I took the bags out and mushed them around to mix the ingredients. The mix had gotten thinner already, and a little darker, by the 1.5 hour mark.

At the end of that step, the pH had dropped below 5.5. Which makes sense because enzymatic pectin degradation yields simple sugars and galacturonic acid.

Next I turned the temperature up to 130 F, a little higher than in the paper because I didn't want too much beta-glucanse action, another enzyme in the barley, as excess product there can cause off flavors. That enzyme tails off at around 130, and I figured it had enough time in the first rest.

That set for 3 hours and 10 minutes, with occasional mushing around to mix. This mash temperature saw the muck thin and darken a lot, especially around the outside of the bags. The pH also rose here, back up to around 5.6 by the time it was done.

After filtering with the nut milk bag, and lots of squeezing, I got around 0.4 gallons of juice with a gravity of around 1.096 and a brix reading of 22. I'm noting the brix, even though I'm still learning to use the refractometer, because it will be useful to track the progress of fermentation and maybe to get my final gravity.

That went in the fridge overnight because it was one freakin' AM.  But I did stick the pulp back in overnight at 130 F with another 30 mL of water to see if more would convert. A little did. In the morning I squeezed another 200 mL of juice out.

Diluting to 1 gal total, my starting gravity reading is 1.030. That's low. I may want to spike it with some simple or malt sugar, but I think I'll wait till primary fermentation slows. I crushed a campden tablet in there and now it'll sit for at least 24 hours.

Final Brix is 2, which is about 1.008 in gravity, which says I'm at around 3.15% ABV and that the yeast did a good job converting all those sugars into alcohol. The taste is very plain without any recognizable banana flavor, at least from a small sample. I'm going to bottle condition it with more banana extract.

Wow, these are terrible! Bitter and sour, not really fizzy, and no banana flavor! More like a bad banana cider. But there's one big huge trick in the hard cider world: If it sucks, let it sit in the bottle for longer! Sometimes a cider that is ghastly in January 2020 is actually pretty decent in Feb 2021. I'll update this in the latter-named month :)