Okay, so I wrote the company...
"You are correct. Water and water soluble substances do not wet hydrophobic
materials, like our PET carboys and fittings. These plastics "do not like
water." Glass is hydrophilic ("loves water"), so water and water soluble
substances will wet glass. In relation to fermenting wine and beer,
hydrophobic materials are less likely to take up water and water soluble
coloring and flavors (flavor scalping) and they are easier to wash than
glass. "
Regards,
Sandy
Editorial Department