i have been brewing 1gallon batches and all grain. i have been fermenting in costco 1gallon apple juice bottles. it is easy to siphon and you can see where the yeast cake lies after cold crashing/lagering. i have been working on inverting these with two 3/8 wholes in the cap one with a small tube to the top to vent co2, the other for harvesting yeast. i have pressure tested these to over 20psi, and think they can be used as a tap a draft, working on the fittings now. normally if i don't brew on the yeast cake i swirl it up and put it in a sanitized bottle and cap it through it in the fridge till i can make new starters.
my first time with this small all grain i tried to brew in the bag. not very efficient but possible. tired of the low efficiency i have converted my plastic bucket fermenter to a mlt. works just like a coleman but not insulated (and not blue
) i have also toyed with using an electric roaster oven to mash in. can stir and control the temp but a little difficult to get the wort out, so probably will not go down this path.