If you enjoy the smell of boiled red cabbage in the morning. 
I don't have trouble with cabbage-stink with my recipe, which does not involve boiling.
To make 50-60 ml of indicator, I put 50 g of red cabbage from a whole head, and
50 g of 95% EtOH in a blender. I use "Everclear" which, in USA, is sold for drinking,
and is thus expensive (tax) but won't contaminate my blender which I do eat out of.
Blend for a while, and filter once or twice through coffee filters. If I tried to squeeze
out the goop, I'm sure I could get more indicator solution, but I usually don't bother.
This seems to work well, and doesn't stink up the place. (I'm not making large
amounts, though, nothing near 4 liters.)