Wash aeration

[Almanac]

We don't send people to the corner here, we're more civilised than that.

Now, out to the Naughty Step for you

AM

[Almanac]

Small update:
A beer brewing friend recently suggested that one way of preventing yeast foaming out of it's container when making a yeast starter might be to add a little anti foam agent to the mix.

After giving it some thought I decided to run a trial on a ferment that has a tendency to foam quite a lot and set up two Demi-jons with 4litres each of a lentil wash identical in every respect except one.

One batch was dosed with 3ml of Distiller's Conditioner and the other was set off without.

That was on the 17th of Feb and they both started off more or less the same. 24 hrs later there was a marked difference. The'normal' one had a healthy Krausen but while the other one had none it was bubbling at the airlock at half the pace of the untreated wash.

The wash without the conditioner finished with a FG at 0.986 on 21 Feb and cleared by the evening of 24 Feb with little help from me other than a good degassing.

The wash treated with conditioner is still fermenting and the Hydrometer now reads 0.996.

Edit on 06 Mar: I racked off the anti-foam treated wash last night and it has a FG of 0.990. I forgot to include that both had a SG of 1.082

My conclusion is that while adding an anti foam agent does indeed suppress the formation of foam it obviously interferes with the fermentation process by slowing everything down. I'm guessing that the mechanism by which the anti foam agent prevents the formation of bubbles also prevents the wash from holding onto gases in the liquid like oxygen, needed for the aerobic phase of fermentation where the yeast multiplies, thereby making the anaerobic phase much longer.

Seems like a reasonable supposition.

AM