Low Calcium, how does it effect fermentation

[Sugar89]

Hi all,

I have very lower calcium in my water (3.8 mg/l) and I am wondering if that might have had an impact during fermentation. My last two batches haven't reached my final FG and I wonder if this caused it because the yeast struggled to do their job?

I have been brewing pilsners and they were coming out fine which I have since learnt can be brewed with low Calcium, my last two brews have been a golden Ale which has failed to reach its FG

What are your thought?

Cheers

 

[Quokka42]

Low calcium tends to affect mash efficiency and get yeast off to a slow start. You haven't mentioned your recipe, so it is hard to comment, but a pinch of gypsum or calcium chloride is probably a good idea for your ales.

 

[Jack of all biers]

You want minimum 50 mg/L calcium (Martin Brungard argues this is not necessary for Lager yeast, but well, 3.8 mg/L is low even for that argument) and a maximum of 150 mg/L in your wort. The grains will add some calcium to the wort liquor, so the water is not the only source (I'll assume that because you posted in All Grain that that's what you do), but I'd bump your calcium up to 50 mg/L as a minimum.

Calcium effects mash pH and assists flocculation of yeast, but it's not a limiting factor for yeast growth and fermentation in a malt based wort. I'd be looking at your yeast pitching rates, aeration, yeast vitality issues (lack of health) or lack of other nutrients (FAN, zinc, vitamins) before looking at low calcium.

Take a look at your water make up, fine. This will improve your beer, even if it's through your understanding of what effects what, but for yeast not reaching FG, then I'd be looking more closely at the fermentation side first and wort production side last.

 

[Lionman]

You mention the lagers you did seemed to go alright but the ales seemed to finish high.

What OG were the pilsners?
What OG were the ales?
What yeast was used for each?
What temp did you ferment at for each?
How much yeast did you pitch for each?
How long was primary fermentation?
Did you aerate enough?
What temp did you mash at?

I would be making sure there are no issues in your process in these areas before going down the water chemistry path too far.