by warra48 » Sunday Jul 01, 2012 7:58 am
From Palmer's "How to Brew":
Medicinal
These flavors are often described as mediciney, Band-Aidâ„¢ like, or can be spicy like cloves. The cause are various phenols which are initially produced by the yeast. Chlorophenols result from the reaction of chlorine-based sanitizers (bleach) with phenol compounds and have very low taste thresholds. Rinsing with boiled water after sanitizing is the best way to prevent these flavors.
The common link in your OP may not be just the person you source your ingredients from. There are other possibilities, such as incomplete rinsing after sanitising (unless you use a no rinse sanitiser), the water you use (may have chlorine or chloramine - do a search on how to deal with this), too high initial fermentation temperature, underpitching yeast (which will stress it and cause unpleasant characters in your beer, and is not unusual with kit supplies yeast).
My advice:
1.Find a reputable local supplier, or use mail order from a reliable source such as CraftBrewer or Grain & Grape.
2.Look at your water, and if needs be, boil it the day before, and let it cool overnight. It will remove any chlorine. If your water supply has chloramine, investigate using Campden tablets.
3.Use a proprietary yeast from a producer such as Fermentis (Safale and Saflager), Danstar, or investigate liquid yeasts. CraftBrewers repackaged yeasts will also give you a decent quantity and quality per pack.
I don't believe your beers are infected, but you need to start a journey to try and improve your ingredients and processes.
You will get there, hang in and don't give up!