This means that more WVO gets transesterificated. Well, any analytic chemist will tell you that if you don't work with fresh chemicals and in at least three parallels, you won't get accurate results. For the second stage you don't need any new equipment, just some more time. Wear proper chemical-proof gloves, apron, and eye protection and do not inhale any vapors. Methanol can cause blindness and death, and you don't even have to drink it, it's absorbed through the skin.
Sodium hydroxide can cause severe burns and death.
Together these two chemicals form sodium methoxide. This is an extremely caustic chemical. Always have a hose running when working with them. The workspace must be thoroughly ventilated. No children or pets allowed.