Advice About Fresh Worts

[pint of lager]

Warning, pitching onto a whole yeastcake can lead to overpitching of yeast, which may give explosive ferment, high temperatures, cloudiness, off flavours and underattenuation of the finished product.

Page 90, "Principles of Brewing Science" by George Fix.
"Shock excretion refers to the situation where adverse fermentation conditions-most notably high starting gravities and/or high fermentation temperatures - create osmotic-pressure effects on the cell wall. This pressure can cause yeasts to actually reject essential nutrients, most notably wort nitrogen. Lack of nitrogen will inhibit yeast growth, again resulting in a lengthy and disordered fermentation."

Put your wort kit in a fresh fermenter, scoop up two-three desertspoonfuls of yeast off the bottom of your finished brew and use that to star your next brew off.

If you have the knowledge and skills, you could wash the yeast. The safest and easest way is scooping some off the bottom of the primary fermenter.

 

[mje1980]

I must agree about pitching onto a whole yeast cake, no matter how big the beer is. I just recently did my 1st barley wine, and i pitched it ( 1090 ) onto a whole yeast cake from a porter. Well, it dropped from 1090, to 1020 in 24hrs!. While im happy the yeast was healthy enought to handle it, it would've been much better to use maybe only a 1/3 or so of the yeast cake, as im sure the fermentation would have been very hot, and has probably caused some harsh flavours etc. It tastes o.k, but harsh ( its in 2ndary now ), and alcoholicy warm. Obviously, with an alc% of around 10,5%, its gunna be a long time before i can tell how much it has affected the beer, but next time i will definately not be pitching so much yeast. I will save some slurry to pitch to 2ndary if necessary.

 

[jimmyjack]

I have to agree. I have thrown a batch on top of an existing yeast cake with good results but dont recommend it after the first go. I always take a cup full of slurry, clean the primary and then repitch. Its too exspensive to have a bad batch. The Esb kits have got me started on ag and I am going to do my first batch tomorrow morning!!!