Yeast starters on a budget

Under-pitching was behind most of my slow, sulphury lager fermentations. A starter fixes that, but a stir plate felt like an unnecessary purchase.

Shaking the flask every time I walk past works surprisingly well. A two-litre starter of 1.036 wort, shaken often for a day and a half, gets a lager pitch close to where it should be.

I decant the spent wort before pitching so the starter beer does not thin out the batch, and I save a spoonful of slurry in a jar for the next brew.