Extract brew and steeping

[Chris77]

Made an Mosaic IPA used RO water, all went fine except very bitter / tannin taste, had a couple others in past do same so been reading up on what could be wrong. They do mellow a little after 4 months but still 1 or 2 pints is enough.

The Mosaic required steeping the grain (caramalt 250g) for 30 min read about keeping the temp around 65-70c anything over 76c starts releasing tannins I kept a thermometer in the pot and I kept it in range, so happy with that part.

Reading water chemistry the RO should be around ph 7 (Just order some ph testing strips) yet It should be around 5.2 ish for steeping (anything over ph 6 extracts tannins) I know the gains will drop the ph as slightly acidic but the recipe called for 6lt of water, reading online Ro and that quantity of gains comes back at 1 - 2lts max of water in estimates any more and the Ph will be too high, so guessing this is my problem I'm extracting the tannins.

The part I'm struggling with is adjusting the water, Should I do the whole 19lts to ph 5.2 then take 6lt an do as normal or do the boil with 2 ltrs. The Ro water is great for the extract as that has the minerals already in it so treating the water prior will this then create more problems.

 

[Hazelwood Brewery]

RO water is pretty pure and although it should be about pH7 it immediately becomes acidic because it soaks up CO2 from the air like a sponge. However, RO water has virtually no salts so it has no buffering ability (capability to resist pH change) so it will easily change pH.

You can give your RO water some buffering capability by adding a little calcium (Sulphate and/or Chloride). You can also add a little lactic acid to acidify the water if you wish.

I have to say though that I never have an issue with tannins from RO water, treated or otherwise.

 

[Chris77]

Hi thanks for replying think I will try a little calcium on next brew see what effect that has.

 

[An Ankoù]

Might be wrong, but I don't think it's necessarily your water chemistry. Could you give us the full recipe?

 

[Chris77]

The sort version as I'm following a kit.

6 Lt water steep 250g caramalt for 30min 65-70c
bring to boil add 1 kg Light malt extract plus 75g cascade boil for 70mins, add 1.5kg light extract boil 5mins, switch off add 30g mosaic then cool.

Then when to temp add yeast and dry hop after 4 days with 50g mosaic for 5days.

Left to ferment out around 3 weeks till no bubbles then kegged.

 

[Chris77]

I think I made another mistake (not brewed for about 5 years getting back into it) and kept a lid mostly on during the boil but reading about dms I don't think this is the issue.