Fermenting on the trub from the boil kettle

[Liam Callaghan]

I was wondering if anyone could shed a little light on this for me?

If I was to cool the wort down in the boil kettle and just pitch in the yeast, seal and let it ferment from there.  What would be the negative side effects on the beer?  I would be looking to transfer to secondary vessels a week or so later but unfortunately the volumes I am working with now (approx. 70 litres) don't fit into the fermentors I have (30 litre) and it would be awesome to just use the boil kettle.

Then I can just lift it off and put on another BK for the second batch.

[Mark Jackman]

The hot break would be my main concern.  The cold break isnt an issue and provides nutrients for the yeast, but the hot break may lead to some off flavours in the finished beer.  Sorry I cant be more specifc as to what flavours to expect, "less clean" would be my best guess.  Try a side by side with a split batch and see how much of a difference (if any) it makes, taste of perception will also obviously be different between styles.  It would make an interesting experiment and I'd be happy to help you sample them ;)

[vince costanzo]

The main issue is that you will get more off-flavours.

There will be an increase in fatty-acids, some of which will taste like soap.

Also you will find the beer is more astringent, and more esters which could include solvent like characteristics,

But from a process point of view, if you cool with a heat exchanger then the risk of blockage increases and consequently risk of lactic acid bacteria causing sourness in the beer.

[nicholasmarmon]

give it a try and hope for the best....

[Ralph]

Dec 2011?

Did you try this Liam? How did it work out for you?

[vince costanzo]

Trub can have a negative effect on beer including soapiness from the fatty acids, astringency or harshness, increased esteriness (fruity or solvent characteristics) and may even lower the bitterness of your beer.

If consistency is important to you you need to separate the trub from the wort.

Vince