Right the experiment is happening as we speak, as per usual I have fiddled around with the recipe and changed water volumes a bit as I expect slightly higher losses on the smaller batch with my kit. Here is the recipe, I have upped the late hops and included some Liberty as I fancied trying this in an English ale. Hopefully the extra hops may make changes to the treatment more obvious....
Boil Size: 8.01 l
Batch Size (fermenter): 5.00 l
Estimated OG: 1.038 SG
Estimated Color: 9.6 EBC
Estimated IBU: 28.8 IBUs
Brewhouse Efficiency: 70.00 %
Est Mash Efficiency: 74.2 %
Boil Time: 60 Minutes
Ingredients:
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Amt Name Type # %/IBU
0.82 kg Maris Otter (Crisp) (7.9 EBC) Grain 1 94.3 %
0.05 kg CaraGold (12.0 EBC) Grain 2 5.7 %
5.50 g Challenger [7.50 %] - Boil 60.0 min Hop 3 22.3 IBUs
0.07 tsp Irish Moss (Boil 10.0 mins) Fining 4 -
7.50 g Goldings, East Kent [5.00 %] - Boil 5.0 Hop 5 4.0 IBUs
7.50 g Liberty [3.00 %] - Boil 5.0 min Hop 6 2.4 IBUs
0.2 pkg Nottingham (Danstar #-) [23.66 ml] Yeast 7 -
Mash Schedule: Single Infusion, Light Body, Batch Sparge
Total Grain Weight: 0.87 kg
Both batches will be treated with a 1/4 campden tab for dechlorination.
Otherwise the first batch uses the water as is from the tap.
The second batch I have decided that I will use CRS to strip out the carbonate and gypsum but I will only add the salts to the kettle, that way I can put any changes in efficiency down to CRS alone and changes in flavour to a combination of the CRS and the Gypsum.
I measured the alkalinity of the water again today and it has gone up a bit to around 228 which is back where the water report places it. Interesting to see that much variation in such a short time. Water PH was measured at 7.7 which was a big jump from 7.5 (suspect the meter may need recalibrating?).
Based on the water values the calculator on this site gives 11ml of CRS for 10L total water for a Pale Ale, this is matched by the Jimsbeerkit calculator and this value also works on the brewerfriends version (my previous issues with the values given by BF were down to me using it wrong).
I will add 1.4g Gypsum to the kettle for the second batch, this is in the rough ballpark for salts given by the HBF calc (although this does ask for Epsom salts as well) following previous advice and to keep things simple I will stick with a single compound for now. The JBK calc advises even more additions for a dry pale ale with a total closer to 3g. The BF calc says that all values are within normal brewing range with these additions and that the Sulphate to Chloride ratio is at 2:1 which should boost hop flavour.
Putting the grist info on the BF calc also gives an estimate for mash PH which comes out at 5.72 or just outside the ideal range with no treatment, with the treatment it estimates 5.4 for the mash PH. I measured PH of the untreated mash at 30 mins in and it came out at 5.9ish which is pretty high but again about 0.2 above where it should be which makes me suspect the calibration again.
All seems to be going well so far apart from mash losing temp a bit quick (I dont think my mashtun works too well with a batch this small) but as long as I do everything the same on the second batch it shouldnt have too much of an impact.
Untreated beer is just coming to the end of the boil now, will report back as I go.....