I’m just experimenting with a yeast starter and have added a second serving of wort which resulted in an additional day or two of activity. Now things have stopped and I added another serving of wort and am waiting to see if more fermentation and yeast growth occurs. I don’t plan to brew again for about a week or so. Can this starter keep going through this cycling until then? I read in one of the brewing bibles about a starter that had been build up several times but there was no information about how this was done and what, if any, was the limit. My intention is to increase the pitching rate without having to buy so many vials of liquid yeast. This starter was from new vial of liquid yeast. Thanks.
it depends on the gravity of the wort you are pitching into finally. Generally if you are stepping up a starter you want to pitch the tube of yeast into say 1 qt (or litre if you prefer) of 1.030 wort and when that is complete cold crash, decant the liquid and add another 1 or 2 quarts, complete, crash, decant, repeat.
That being said I think that if you need that much yeast it might make sense to brew a 5 gallon batch of 1.030-1.040 beer and use the eyast cake from that. Unless your making lagers in which case someone else will have to chime in as I have not done one of those.