Post
by Eric » Thu Feb 22, 2024 12:04 am
This would not have happened but for a tin of Coopers Dark Malt Extract bought for some forgotten project was to be used in a Fullers Brown Stout recipe of 1897 by Ron Pattinson. His recipe didn't include extract, but extract made a 1075 OG brew easier (with a couple more points) reducing both grains and sugars.
Initially I was surprised by my findings, so much so, I set about to recalibrated my pH meter using new buffers, but there was to be insignificant difference.
The RO water registered 1 on my TDS meter, my tap water gave a reading of 578. From this the RO water could be assumed to have near zero alkalinity while my spreadsheet suggested the tap water had alkalinity of 279.2ppm as CaCO3.
Previously I had used a figure of 125g for liquid malt extract in a litre of water to provide a 1040 wort, and this figure was used. When measured by refractometer, the reading was slightly less at 9.3 Brix.
pH of wort made with tap water measured 5.50, that with RO water was 4.64.
As said, I was initially shocked by this finding and wondered what adverse influence it might have had on my Brown Stout as this wasn't an assumption I had made. It would seem, and I can only think this is the case, that the manufacturer made no pH adjustment to this extract as the findings are more or less what I would expect if Brown Malt was mashed in RO water and my tap water. This suggests brewers using extract may have to treat their water as would an all grain brewer for that style of beer the extract will make. I didn't expect that, but then I've never thought about this before now.
Without patience, life becomes difficult and the sooner it's finished, the better.