In my (very little) experience, I have a HBT theory. Not on what causes it, but on when it arrives?!
I’ve done four extract brews to date, all different, and three of those four have what I can only assume is the HBT! Exactly the same slightly bitter aftertaste never experienced in any shop bought or pub beers, ever.
All my brews followed the same process using ASDA spring water. Ie 2 weeks FV at 22 degrees, 2 weeks bottled 20 degrees, 2 weeks shed 8-12 degrees.
Brew 1 was a Festival Razorback IPA. Although a two can (bag) kit, this did come with 1kg brewing sugar which also had to be added
Brew 2 was a Simply Mild kit. This was made using 1kg brew enhancer
Brew 3 was a Mangrove Jacks Bourbon Barrel Ale. This was made using 600g Mangrove Jacks LME
Brew 4 was a Simply Pale Ale. This was made using 1kg brewing sugar and 500g Hopped DME.
Out of all of the above, the only brew which doesn’t have the HBT is the Bourbon Barrel. Now, its possible that it’s there but masked better by the Bourbon flavors but it is actually the only one which was made using no other sugars apart from Malt.
However, whilst I was compiling all this evidence and almost ready to blame added sugar for this odd after taste I’m getting, a strange thing occurred to me. I have taken a gravity reading of every brew just before bottling and as I’m not one to waste beer, I’ve given each of them a very good taste sampling at the same time (well, it is called a trial jar after all) and never have I experienced this twang at that point. The beer isn’t fantastic. For a start its flat and at about 20 degrees, but there’s no twang! It seems to only appear after bottling. Has anyone else found this twang only appears after it’s been bottled?