What happened to the Bananas?

I have experimented with wheat beers quite a bit and have always ended up with nice, drinkable beer, but the buggers never turn out the way I want them to.

The first time I did a wheat beer, I was trying to do a Wit beer, also known as a Tarwe or Blanche beer. The best known example of this Belgian style of beer would have to be Hoegaarden, but that does not make it the best example, by any stretch of the imagination. Just the only one on the Irish market.

I cooked up a wheat beer, using a mix of barley and wheat malt and added coriander and orange peel to the boil. (I know using malted wheat isn't the traditional Belgian method. Now ask me if I care.) The exact proportions are lost in the mists of time, along with the brew book I was using, but I do remember I went a bit mad with the coriander and ended up using something in the region of 40g of the stuff, all told. I used Brewferm Blanche yeast to ferment it, as I am fond of dry yeast in general, having had a lot of success with it.

The resulting beer was actually quite nice… once you got over the shock of having such a pronounced coriander flavour in a beer.

 

The next one I did was of a similar recipe, but with a lot less coriander. I thought I was onto a winner, but the yeast had other ideas.

 

Did you know that Brewferm Blanche yeast can produce isoamyl acetate (the ester associated with the taste and aroma of bananas)? I didn't, but this next blanche beer had it in spades! Incongruously, the coriander and orange peel still came though, alongside the banana. Again, the beer was quite enjoyable, in its own way, but it was not the beer I was going for.

 

The next one was originally going to be a straight Weissbier but I just couldn't resist mucking about with it. The grist ended up being like this:

 

3Kg Pale Malt.

2.5Kg Wheat Malt.

0.5Kg Crystal Malt.

 

I actually undershot my original target temperature, so I went mad and did three decoctions, to raise the temperature, which is actually the traditional way of mashing a Weissbier. Not that I knew that at the time.

 

The boil (which I did the next day, by collecting the wort in a sanitised plastic bucket with lid and storing it over night) actually involved three hop additions, which I would not do now knowing what I do about Weissbier brewing techniques, but this is how the hop bill looked:

 

60 Minutes: Tettnang: (4.3% AA): 30g

20 Minutes: Tettnang: (4.3% AA): 20g

7 Minutes: Tettnang: (4.3% AA): 10g

 

Again, Brewferm Blanche yeast was pitch; my logic being, if it wants to produce isoamyl acetate, let it produce isoamyl acetate in a beer where it belongs.

 

But did it produce isoamyl acetate? Did it f**k! Not a hint of the stuff. This beer came out fruity and nice, but it was no Hefeweizen. Don't get me wrong; this was a beautiful beer and I was far from the only one who thought that, but, again, it just wasn't the beer it was supposed to be.

 

For the next wheat beer I tried, I went hard core with the grist and hops:

 

Grist:

2Kg pale malt

3Kg wheat malt.

 

Boil:

60 Minutes: Hallertauer Mittlefruh: 12 IBU

 

And again, I pitched Brewferm Blanche yeast, hoping for the isoamyl acetate I know it can produce… naturally, I didn't get it.

 

I got a lovely beer; nice, fruity, refreshing; everyone loved it, but where are the damn bananas? I got them when I didn't want them, so where the hell are they when I do?

 

As I now know a bit more about yeast and the way it behaves, I am starting to suspect that the reason that I got isoamyl acetate that one time is because the yeast was stressed.

 

I didn't treat it any differently than the other times and the fermentation conditions were fairly similar, but it is quite possible that the yeast sachet that I had that time was older, or had been subjected to extremes of temperature, before I got my hands on it.

 

If this did happen, there might have been fewer viable yeast cells in the sachet, causing the surviving yeast to go through an extended growth phase, which is associated with the production of precursor chemicals to some esters, including isoamyl acetate.

 

If I am correct in my thinking, it should be possible to use a healthy sachet of Brewferm Blanche yeast to produce a wit beer. Furthermore, it should be possible to use part of a healthy sachet of Brewferm Blanche yeast, thus forcing an extended growth phase, to produce a Weissbier, complete with isoamyl acetate.

 

With this in mind, I started brewing and the first step has to be a wit beer:

 

Grist:

2Kg Pale Malt.

2Kg Wheat Malt.

 

Boil:

60 Minutes:

Fuggles (4.5% AA): 27g

15 Minutes:
Curacao Orange Peel: 25g
2tsp. Ground Coriander Seed

5 Minutes:
Curacao Orange Peel: 25g
1tsp. Ground Coriander Seed
0.5tsp. Ground Coriander Seed

2 Minutes:
0.5tsp. Ground Coriander Seed

 

Again, a full sachet of Brewferm Blanche yeast was pitched.

 

This beer started out at a gravity of 1.045 and was eventually primed with table sugar and bottled, when the gravity had been at 1.009 for over two weeks.

 

After two weeks in the bottle it was quite drinkable. After three it was great! The peel and coriander are right there in the nose and there is a wonderful bitter-sweet citrus flavour, with a chewy malt and yeast body.

 

And no bananas! Yes! This time the yeast did what I wanted it to do! I wanted a wit beer and it gave me a wit beer.