Looking at creating my first yeast starter for a DIPA recipe with on O.G. target of 1.085.
For this O.G. Brewer's Friend is telling me I would need a 3L starter of an O.G. of 1.040 with a stir plate to hit my cell count (assuming yeast is 1 month old) (oh, I'll also be buying 2 packs of yeast).
The yeast starters work far better with a stir plate, however, stir plates cost an absolute fortune and there's no way I can justify spending that kind of money.
What viable alternatives are there to stir plates which will help the starter?
Maybe some sort of underwater fan? Placed in such a position to the side of the vessel it creates the same whirlpool?
Also, erlenmeyer flasks cost an absolute fortune. With additional headroom over 3L the flask would need to be 5L? At that size they are very costly. Altogether with a stir plate that seems to be coming in around the £500 mark. Is there any particular benefit of an erlenmeyer flask? Surely any ol' container will do? I've seen a pretty huge glass vase in the local charity shop for a few quid and I'm hoping to hear that'll do just fine.