# Water hardness and effect on bloom



## Dumnorix (Dec 29, 2017)

Hi, I am currently on holiday in North Devon near Bideford with the family, and have brought my chemex and hand grinder. I normally use Waitrose Lockhills in both my Sage DB and also when I use the chemex/ aeropress, but I am just using the tap water at the moment. From the state of the kettle (absolutely zero scale) I figure it is a pretty soft water area. When I started the pour (currently using Kenyan beans from Redber roasted on 17th July) so much gas was given off during the bloom I almost thought the chemex was going to boil over! I am assuming this is due to the water being so soft, although I haven't used these beans with Lockhills yet so have no point of comparison, but I have never seen a bloom like that before. The only other thing that may have a bearing on the situation is that the beans were supplied in a bag which had no degassing valve, so not sure if that could make a difference too? I would be grateful if someone who knows more about the science of this than me could shed some light on what is going on?!


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## MWJB (Feb 28, 2012)

I think the quantity of coffee (more = bigger bloom), degree of roast (darker = bigger bloom) & coarseness of grind (coarser = bigger bloom) would have the bigger impact on bloom.

If your coffee quantity & grind setting are your typical settings, my bet would be on the roast.

I switch between very hard tap water, Lockhills, Volvic & Deeside (very soft) and don't notice much difference.


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## Dumnorix (Dec 29, 2017)

Yes, quantity and grind are my usual settings. As these are beans I have never tried before I guess it must be the roast in that case. Many thanks for clarifying.


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