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Good to meet you Sean. Enjoyed your article on wheat beer and am delighted to find this excellent site. My own experience with brewing wheat beers is that if the fermentation temperature is kept up at 22-23*C more of those banana flavours develop. I've always used liquid yeast for wheat beers in the past - where did you get the dried yeast from? I'd certainly like to try it. Shaun Hooke

Welcome shaunhooke

There are two dry wheat yeast on the market
The first was from Safale, T-58 supposed to make a good wit.
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The second is from Brewferm Blanche also make a good wheat beer, but in my opinion it more of a wit than a hefe.

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If cellular metabolism is responsible for the various esters that typify styles then consideration should be given to the amount of break material in the wort because this effects dissolved CO2 levels and CO2 levels effect yeast metabolism. This is why some brewers close the vents on their fermenters therby increasing dissolved CO2 and pressure and limiting yeast metabolism.

Likewise an increase in temp will generally increase all chemical and biochemical reactions in the fermentation. The reason we get esters and other flavour compounds in beer is because they spill from metabolic pathways that are running at full speed or the yeast accumulates excesses to help it survive and then doesn't use them.

I've read that twice, and my head hurts. A monday morning thing, I guess. I'll try again later.

A common example we are all familiar with is the production of alpha acetolactate. This molecule is part of the pathway for the biosynthesis of the amino acid valine. If acetolactate is formed quicker than than the next enzymne in the chain can convert it to the next product it spills from the cell and is spontaneously converted to diacetyl. So if the pathway is going hell for leather more of the compound will spill from the cell. Happily for us the yeast reabsorb the diacetyl late in fermentation when things have calmed down a bit and convert it to acetoin, which has a high flavour threshold and we genarally can't taste it.

It seems to me that you are certainly going to get a cleaner beer if you can control fermentation temp. It makes me want to invest in some form of refrigeration because a lot of hard work in recipe formulation and careful mash technique could be negated by poor fermentation control and subsequent formation of unwanted flavours.

Thanks Oblivious

I will try those dried yeasts in my next wheat beer. How do you get hold of these things? I've been just stocking up every time I go to the UK.

Shaun