Not sure exactly what the lag times are but they were no different from other dry yeast I have use, hence really pushing the tap idea.
No probs - lag time is commonly considered to be the time elapsed between pitching the yeast and the appearance of active fermentation in primary, including the formation of krausen (the dark coloured / highly bitter foam layer on top of an actively fermenting wort). Usually brewers like to keep the lag time to under 12 hours and if you pitch well planned yeast starters at high krausen the lag can even reduce to under an hour. Lag time is not necessarily a bad thing, but the sooner your yeast finishes the aerobic adaption phase (where the cell population grows) and starts the anaerobic attenuative phase (where the yeast population starts to reduce the gravity / sugars in the wort and converts it to alcohol and CO2 byproducts), the better. All of this, of course, is dependent on a myriad of factors, including starter size, volume of wort, temp of wort, viability of original yeast, characteristics of each yeast strain, and some have even argued the geometry of the fermenting vessel itself!
All bottles had a very vinegar taste to them
Ok, that tends to support the bacterial infection issue - the vinegar / acetic acid taste is often caused by aceto bacterial contamination or a wild yeast strain. You may have an infected tap or you might have scored a poor yeast sachet, or you overlooked or undershot on your sanitation protocols.
The next batch was an non-alcoholic batch and hence was in the fermenter for approx 30 mins and then bottled. The only problem with this batch was a ring of dark murky film on the top of the liquid in the bottle. Taste great by the way but still not the norm.
30 minutes in the fermenter? :blink:
The ring of dark murky film you describe was probably krausen! :huh: Obviously, I don't know what you made the non-alcoholic batch out of, but surely you used some sort of sugars in the solution, which the yeast converted to alcohol and CO2. You must have had some sediment in the bottom of the non-alcoholic bottled batch...Why only 30 mins - that's a sure fire way to make a bottle bomb - unless you used next to no sugars and didn't use any yeast at all?
Giving everything a damn good clean and replacing the tap are good ideas but I'm not convinced beyond reasonable doubt that it's the tap at fault - perhaps you did something that contributed to an infection, that more than likely ended up at the tap...I hope you have better luck with your future brews after the big clean.
Cheers,
TL
