I am going to be doing a beer in the next few weeks that has an OG of 1.070. I will be doing a yeast starter for the first time. Based on some online calculators it's telling me I need approximately 323 billion yeast cells for a 5 gallon batch. By my math and the math of the same online calculator, that means I need a starter size of about 7 liters. That is a huge starter....How is that even manageable? Do I really need a starter that large?
I can't imagine ever needing a yeast starter even close to that large for a 5 gallon batch. My last three starters were between 1L and 1.5L, and during that time we've made a really beautiful IPA and American stout, which each started with OGs of 1.062. It definitely depends on the age of your yeast, but in each case we used fairly fresh WLP001.
For those starters, we used roughly 6 cups of water to 1.5 cups of DME, and let it sit on a stir plate for 24 hours. Unless your OG is extremely high, and unless your yeast is really old, I don't think you can go wrong using a starter beween 1.5L and 2L.
Since you don't have a stir plate, swirling or shaking every so often will definitely help yeast growth.