too many bicarbs and high alkalinity and PH in my well water. im going to try a starter using light DME at 1.040 wort SG, .5gal.
should i be adding calcium chloride (50ppm) and adjusting around 5.0-5.2ph also to make sure its optimal for yeast growth?
Wouldn’t it be easier just to use Spring Water instead that would have some mineral content?
spring water varies from bottle to bottle on mineral content. might have 2ppm calcium or 60ppm. distilled is neutral starting point, so you can then control what you want to add - that’s my thought process.
otherwise, if i use my well water, i have to bomb it with lactic acid to drop the ph, and add calcium.
The DME will give you all the minerals you need. Only thing you might want to think about adding is a bit of yeast nutrient.
This^^^^
The malt extract will have some minerals from the mash it was made from. How much is the question?
You can add a little CaCl2 if you want. Yeast benefit from some calcium. A little energizer is not a bad idea either, as it will have trace minerals.
Hmmm, what is the pH optimum for yeast growth? Something around 5.2-5.5 is good for the mash, as you need to get it working in a range for the enzymes. You are not mashing here, just trying to grow yeast. A quick search says 4-4.5 is good for growth. Dr. Tom, any wisdom?
that was my question - i couldnt figure out the mineral content in dme.
i do add yeast nutrient (not energizer), so will stick with that as usuall.
so i guess the plan would be distilled water and DME, and keep the calcium chloride addition to make sure i have enough for optimal yeast health and growth (greater than 40ppm) - adjusting PH if not 5.0-5.2.
I think you’re over-thinking this. You don’t need to worry about pH since you aren’t mashing, and you don’t need to worry about flavor since you won’t be drinking the starter. Biologically, I think it would have to be better to use the hard water since it’s closer to being isotonic.
+1
i actually don’t have hard water - its temp hardness hence the ability to manipulate it.
anyway, i’m just curious about starter PH - seems some out there say starter PH is an important thing to yeast growth - as is calcium. just wondering if the scientists out on the forum can comment.
No matter how high in alkalinity it is, the buffering capacity of water is poor compared to the extract. Even if the wort pH ended up as high as 7 (which I seriously doubt), yeast do very well on pH-neutral growth media.
As far as micro-nutrients, the extract should have everything you need. If you want, you could also add some yeast nutrient as insurance.
For a starter, I too wouldn’t use distilled. I think there’s too much opportunity to over/under adjust.
RDWHAH
“No matter how high in alkalinity it is, the buffering capacity of water is poor compared to the extract. Even if the wort pH ended up as high as 7 (which I seriously doubt), yeast do very well on pH-neutral growth media.”
i understand your point that yeast do very well at ph-neutral, but if they do even better at a lower ph of 4.5-5.0, then why wouldn’t you want to do that. i’m reading this is the case, but i’m curious if anyone has experimented with the starter ph and can speak to the results.
It could be a case of “reverse experiment”. For instance, I don’t worry at all about minerals or pH of my starters and I get great yeast growth from them. It certainly isn’t gonna hurt to experiment with what you’re talking about, but you might want to give it try without the adjustments first and then compare the “easy way” with adjusted water for a starter.
Denny-
you’ve seen my water report. i have almost no calcium and a higher PH than many. would you expect that that doesn’t matter, and that the DME and yeast nutrient lowers my Ph and adds enough for a healthy starter?
Yeah, that would be my guess. You won’t know til you try, though. Truthfully, if I was in your position and worried about it, I’d go the distilled water route. When extract is made, the grain is mashed with the appropriate minerals for the mash. They’re still there in the extract and extract brewers are often encouraged to use distilled water for just that reason. I think you may be overthinking things based on the slow starter you just had. I appreciate your desire to get the best performance possible, but by my pragmatic thinking I’d start with the easiest thing you can do, evaluate that, and work from there.
guilty of thinking too much…the nerd and love of science in me. :
Dude, I SO understand! 
Nice to meet you pots. I’m kettle. ;D
Yeah, I was thinking of you (and a couple others here!) when I wrote that!