Adjusting pH of starters

[logdrum]

Hello. Will dropping my pH7.2 filtered water/DME starters down to pH5.4 (or so) improve the health of the resultant yeast? I always decant the spent beer. Thanks

 

[shanecb]

Are you sure 7.2 is what your starters are at?? That should literally never be the case with even a decent DME.

 

[Gadjobrinus]

Are you sure 7.2 is what your starters are at?? That should literally never be the case with even a decent DME.

I've got really alkaline water (280-300 TA). Haven't tested a starter but I'm positive they were high when I just used our filtered water. Thought to acid treat but not worth it to me. Moved to spring water in 3 gallon jugs.

 

[shanecb]

I've got really alkaline water (280-300 TA). Haven't tested a starter but I'm positive they were high when I just used our filtered water. Thought to acid treat but not worth it to me. Moved to spring water in 3 gallon jugs.

I guess but wouldn't you also have the problem of terrible mashes if that were the case, and it were that high?

 

[Gadjobrinus]

I guess but wouldn't you also have the problem of terrible mashes if that were the case, and it were that high?

That's why I do treat my water when brewing. Depending on what I'm brewing, I bring TA down to as low as 30 with 37% HCl.

 

[shanecb]

That's why I do treat my water when brewing. Depending on what I'm brewing, I bring TA down to as low as 30 with 37% HCl.

Gotcha, makes sense. You could def have a pH that high if you're tap has a ton of buffering capacity.

Back to the original question, you might just be better off using store bought water for your starters, and not even worrying about adjusting the starter pH. Yeast do prefer that 5.2ish range, and it's important that they're able to regulate pH themselves which they'd probably have trouble doing with your water's high buffering capability.

 

[logdrum]

pH7.2 is of the water used to make the DME starter

 

[Silver_Is_Money]

Yeast work rather rapidly to provide themselves with what they consider to be an ideal pH environment. They generally adjust their environment to the pH 4.0 to 4.5 range.

 

[mongoose33]

I just use RO water for my starters and everything appears to work out just fine. I've never tested the pH of that starter but the beer sure has been good!

 

[shanecb]

pH7.2 is of the water used to make the DME starter

So that's the water pH before you add the DME, and not the starter pH? Definitely do not adjust that, then. The DME should be lowering your pH into the correct range (unless you have somewhat extreme water as discussed above).

 

[ajdelange]

He has 5.6 - 6 mEq alkalinity. No DME is going to pull the pH of that water down to where it ought to be. It's going to take 5 - 5.4 mEq of acid per liter to do that. This is about 0.4 mL of lactic acid. Ideally he would dribble lactic into the water until he got a decent pH - 5 to 6 but doesn't apparently want to be bothered with that. So his best bet would be to use RO or bottled mineral water with some yeast nutrient added.

The object of a starter is to grow as many healthy yeast aclimatized to the conditions they are going to be put to work in to the extent possible. If they expend much of their available energy in setting medium pH to where they want it they clearly are going to produce less biomass than if they are given a pH they like to start with.

[Edit] Oops. Just realized the 6 mEq alkalinity isn't the OP's so the first sentence doesn't apply. But the priciples behind it do. The severity of the problem, if any, will depend on OP's alkalinity (not his water's pH).

 

[shanecb]

He has 5.6 - 6 mEq alkalinity. No DME is going to pull the pH of that water down to where it ought to be. It's going to take 5 - 5.4 mEq of acid per liter to do that. This is about 0.4 mL of lactic acid. Ideally he would dribble lactic into the water until he got a decent pH - 5 to 6 but doesn't apparently want to be bothered with that. So his best bet would be to use RO or bottled mineral water with some yeast nutrient added.

The object of a starter is to grow as many healthy yeast aclimatized to the conditions they are going to be put to work in to the extent possible. If they expend much of their available energy in setting medium pH to where they want it they clearly are going to produce less biomass than if they are given a pH they like to start with.

[Edit] Oops. Just realized the 6 mEq alkalinity isn't the OP's so the first sentence doesn't apply. But the priciples behind it do. The severity of the problem, if any, will depend on OP's alkalinity (not his water's pH).

Right. All we know is that the starting water pH is 7.2 which really doesn't tell us if anything should be adjusted. That's just a perfectly normal pH for water.

Logdrum, the only way to know if you'd have to change something is to check the actual starter pH or what the alkalinity of your water supply is. I see you're in North Olmsted, would that be supplied by Cleveland? If so your water should be perfectly fine as is.

 

[mongoose33]

What AJ suggested above is exactly what I do--a liter of RO water, a pinch of yeast nutrient, 100g of DME, and I'm off to the races.

Might be easiest to just get a gallon of RO or distilled water and use that.

 

[logdrum]

Thanks for the input folks. My CaCO3 is reported as 86 btw, & I'm not bothered in the least adjusting w acid. I'm guessing shooting for a pH similar to mash pH would be best practice.

 

[ajdelange]

That's 1.7 mEq/L. Not bad. Remember that DME is made by preparing wort and evaporating the water but the wort acids (the non volatile ones at least) remain behind so that DME is going to be somewhat acidic. The best thing to do is make the starter as you usually do (don't forget the yeast nutrient) and check the pH (room temp). If it is below 6 you really don't have to worry. If it is above 6 a drop or 2 (0.9*1.7 = 1.53 mEq ~ 1.53/12.5 = mL ~ 2 drops) of 88% lactic acid per liter should get you close to pH 5.

 

[logdrum]

Perfect! Thanks & will do!