Can you get tannins from recycling wort, or just sparging?

[Seeker]

My last couple or batches have had a weird off flavour that I've narrowed down to tannis.

One was a bit lemony, slightly acid and made the tongue dry like a red wine. The next had more crystal in which covered the lemony taste, but was also a but muddy tasting and made me mouth a bit dry.

I'm using an 80l kettle with a malt pipe and recirculation and sparging by raising the pipe and pouring 8litres of water in the malt pipe.

I also often mash for about 90 minutes, and sometimes more, with the pump on recirc the whole time.

I'm thinking it's bad sparge practice, but could it be the recirc as well? Too much water flow through the mash? Too long a mash? Too fine a crush (I doubt that on the last batch, but maybe?

 

[wide eyed and legless]

Not really any advantage in anything more than a 90 minute mash, sparging to fast or to hot can lead to tannins coming out of the grain bed. Recirculating the wort will not, I do a 90 minute mash recirculating and haven't noticed any astringency.

 

[Seeker]

When it's gone over 90 minutes it's been for convenience.

I think I'll stop sparging for a while then, and hope it gets better.

Does the speed of water flow through the grain bed when recirculating make any difference? I aim to keep the water a couple of inches higher in the malt pipe which is a fairly slow trickle.

Maybe a pint every 20 seconds I guess.

 

[wide eyed and legless]

My recirculation is done at half choke, I keep the grain bed fully submersed without the top plate on but the end of my recirculating arm is submerged, the grain bed is kept lose and the wort flows through just by gravity. Try doing a 'no sparge' if you have room in the mash tun.

 

[Seeker]

I'll do that thanks.

I don't have room, but I can just top up after the mash instead of sparging.