Evening all and a belated merry Christmas. Ive recently gone into liquid yeast and used some WLP 004 Irish ale yeast to do 4 small batches at once but there was fermenting problems ending with it going vinegary. https://www.thehomebrewforum.co.uk/threads/fermenting-and-oxidisation.84722/ .Now I've brewed 2 small batches and have got the yeast as a starter. WLP 007 yeast is now being used. The starter tastes a bit cidery and smells a bit vinegary. When I poured it into the starter it was very thick like a stodgey custard texture. It's been going for about 18hrs now and is all packed at the bottom and when stored up it all settles within about 10 seconds. I was wondering what I'm doing wrong. I've never had any problems with yeast before the liquid yeast?