haze problems with new yeast starin
Recently i switched to a new yeast starin which promised a quicker removal of Diacetuyl (VDK's) from the beer . It reduces VDK's to bellow .07 ppm in 48 hrs in comparisson to our old yeast which took 72 hours.
However this new yeasts gives a lot of trouble during filtration. The haze at 90 deg is at about 1 ebc while with the same process paramets we used to get a haze of .5 ebc with our old yeast. Also the beer is visually clear like our old beer.
Any suggestions/ explainations ?
It sounds more like protein than yeast. Have a good look at the diacetyl rest period. Some yeasts autolyse more quickly than others at the same temperature. You may find you need to pull the yeast off the bottom of the FV sooner than you did when using the old yeast. Ensure the cone cooling is working OK (though my memories of Indian breweries was that you did not have seperate control of cone and wall cooling jackets.) Check the yeast viabilities immediately fermentation ends, and then again just before you crop the yeast. If they drop substantially, if earlier yeast removal and / or cooling doesn't work, teh wort may be deficient in nutrients, particularly zinc, or oxygen.
Maybe that´s the answer...The yeast absorbs Diacetyl faster because it´s a non or less flocculating strain. That is, it stays in suspension longer and can take the Diacetyl out. What is your final gravity with the new strain compared to before? If your final attenuation is higher then that might be the cause.