Mineral-y bite

[Brewer dad]

I'm hoping to diagnose a mineral bite I've experienced in two of my beers so far. I've searched here and other places, and have seen some suggestions such as infection, hop matter, carbonic acid, and others.

Both of these are from extract and in bottles.

The first beer is an old Rasputin clone(stout), with 2nd gen SO4 slurry starter. Blew my stopper off about 12 hours after pitching. First bottle was quite astringent, which I do think was hop matter related. That faded and was replaced by a sharp mineral finish. No roast, coffee, or chocolate flavors. This was bottled in November 2020 and I just finished the last bottle here a week ago(February 2021). The flavor profile stayed to the end, though I feel like the mineral flavor did diminish slightly on the last bottle.

Second is a weizenbock, made with wy3638 Bavarian wheat pitched straight from activated packet. Opened bottle on Wednesday night after 10 days carbing. Got some nice chocolate notes along with banana. Had another last night(Friday), and got nothing but that mineral finish I had in my above stout. Tried another and same thing. I poured the first pretty hard and got a good head, that taste to me seems accentuated by carbonation. Both beers are carved with 4oz corn sugar in 2 cups water(boiled).

I've brewed other beers before and between these, so I'm inclined to think it's not a water problem. We're on a well and had it tested so can provide results if needed. I consistently wash all my equipment and sanitize with star San. Given what's happened with the weizenbock I'm wondering if I didn't pick up infection while bottling. However at least from what I can find that's not a typical infection flavor.

 

[Brewer dad]

 

[Brewer dad]

 

[Brewer dad]

Figured I'd just post the water test

 

[FromZwolle]

Could be old extract. I've picked up a metallic/mineral tinge to older extracts. Could still be the water. well water can often change drastically from season to season as the water table changes with the 'input source' of the water, rain/snowmelt/runoff, etc.

extracts generally have all the minerals you'll need for the beer already in them, so you can use distilled or RO water for the whole batch. that would eliminate the water source as a variable.

 

[Brewer dad]

Hadn't considered the extract. I try to use my ingredients pretty quickly, but doesn't mean they're weren't sitting around for a while before I bought them. I get all my stuff online at more beer.

As I look at my water test I think doing a control batch might be good idea. I hate the thought of buying water, but if gonna buy brewing stuff it's worth a shot. Maybe I can do something with my water if that ends up being the issue. I think it tastes fine on its own, but maybe it's interacting with certain hops or malts?

Could be old extract. I've picked up a metallic/mineral tinge to older extracts. Could still be the water. well water can often change drastically from season to season as the water table changes with the 'input source' of the water, rain/snowmelt/runoff, etc.

extracts generally have all the minerals you'll need for the beer already in them, so you can use distilled or RO water for the whole batch. that would eliminate the water source as a variable.

 

[brewdude88]

I would really look at getting RO water for your extract brewing. When mixed with 0 alkalinity water, malt extract wort will drop to a proper ph for boiling. When mixed with your tap water, the alkalinity buffers the water against the drop in ph, causing a higher boil ph. A high ph during the boil can result in better hop utilisation, but a harsh (astringent) bitterness.

 

[Gnomebrewer]

There are lots of things it could be. The four that stand out to me are:

WATER. As already discussed.
You could easily neutralise the alkalinity in your tap water and still use it if you don't want to buy RO. Ideally, use a pH meter and add acid (lactic or phosphoric) to get it in the 5.0 to 5.5pH range. If you don't have a pH meter (most people don't), use the following:
You have 2.6mEq/L of bicarbonate.
80% Lactic acid can neutralise about 10mEq/mL (in the boil pH range).
So, to neutralise the alkalinity in your water, you need to add roughly 1mL of 80% Lactic acid per
gallon of water. Use a bit less acid if it's 88% lactic.

FERMENT TEMPERATURE.
A moderately high ferment temperature can start to throw unpleasant and bitey esters. Higher still will give fusel alcohols and possibly acetone or banana esters. Control temperatures during the first half of the ferment to the lower to middle recommended range and make sure they stay fairly consistent.

OXIDATION
If you read about oxidised beer, you'd think it's always a cardboard flavour. It's not. Post-ferment oxidation at a low level can lead to lots of flavours and loss of flavours, including a slightly harsh sensation at the back end which could be perceived as minerally. Be careful during bottling to avoid splashing.

CONTAMINATION.
You've already identified it as a possibility and there's no ignoring it. But, if there's no visible sign and bottles aren't becoming over carbonated, I'd say probably not contamination. Keep monitoring for gushing bottles - that's a sign of an unwanted visitor in your beers.

 

[Brewer dad]

Well sounds like the general most likely consensus is water. I'm definitely not the perfect Brewer so not ruling out @Gnomebrewer other suggestions. Though those are things I try to account for and mitigate.

Follow-up water question. Assuming it's the issue, and keeping in mind what @FromZwolle said about well variability, on Brew day I can check pH and make adjustments as needed? At this point I just want to avoid this off flavor, not try to mimick someone's water.

Also, want to make sure I understand "the why" here. The pH/alkalinity of my water can make my hops more astringent? I guess I'm still confused by the delay, i.e. my beer tasted good Wednesday and mineral on Friday. Will do some more research today to see if the flavor is still there.

Thanks so much for everyone's help!

 

[LBussy]

If you want to rule out the water, buy some RO and try that. As others have pointed out, the extract has all of the minerals present in the original mash which is all you need. You are relatively high in certain minerals which could leave a salty or metallic taste, combined with an unknown contribution from the malt, it could push it over the taste threshold.

So, don't worry about pH or anything else - brew with RO the next time and see if the problem goes away. If it does, you know your water contributes to it. From there you can experiment with filtration or simply diluting your well water with an amount of RO water to help things out.

You may not find your test batch is the best beer you've ever done - don't worry about that right now. Concentrate on the "mineral-y" bite. Extra points for a side by side (or split batch) using well water in one and RO water in the other.

 

[brewdude88]

One thought... it sounds like you've made some good beers in-between. Are these trouble children perhaps a higher OG then the others, requiring more extract/gallon which equals higher concentrations of salts, maybe pushing magnesium or something else over the flavor threshold?

Magnesium has a relatively low flavor threshold compared to other salts of ~50ppm. It's possible your existing 12ppm is pushing it when mixed with whatever the extract adds plus the concentration during the boil.

 

[LBussy]

Magnesium has a relatively low flavor threshold compared to other salts of ~50ppm. It's possible your existing 12ppm is pushing it when mixed with whatever the extract adds plus the concentration during the boil.

The Magnesium Sulfate is where I was going with my thoughts ... still, way too easy to brew a batch with RO to test.

 

[Brewer dad]

@LBussy yeah I think a control batch with RO is a good idea.

@brewdude88 that is a thought. The Stouts OG is 1.076 and the weizenbock is in the 1.065ish range don't have my notes handy. So not astronomical but definitely higher than most my other beers. I did do a braggot and a bomm which both came out quite well, but I guess honey doesn't contribute minerals the way malt does. The braggots pre honey OG was in the 40's. I have also wondered if some of the darker malts could be contributing to this as well since these are both dark beers, though Ive done a porter that came out fine.

Thanks for the help!

 

[LBussy]

That rings with the MgSO4, but a test will show for sure.

 

[Brewer dad]

Just an update, started a batch with RO only today. I was debating about doing the same stout kit to get apples to apples comparison, but didn't really want a stout right now. Went with black ipa to try to at least get kinda in the ballpark. It also cleaned out my brewing pantry, and some of the ingredients also were in the dunkel.

The dunkel has mellowed out somewhat on the bite, but still some mineral and not much character from the malts or yeast.

Will report back when I get to taste this beer. Still not ruling anything out at this point.

 

[Brewer dad]

I have tasted the black IPA a couple times already despite it being not even a week since bottling. To me it tastes very clean, and frankly came out about as I'd hoped. I'm not getting any mineral element in the finish. Biggest problem is that halfway through bottling I realized I'd forgotten to add my carbing sugar so half the batch is flat.

I have also made some headway into researching the first two beers. I'd never actually had the Old Rasputin stout, and bought the kit for it based on description/reviews. After finally being able to try the commercial version recently, mine was actually not far off. Mine had the mineral element as stated, but actually didn't care for the commercial version either.

My dunkelweizen also seems to have changed a somewhat after some time. Mineral flavor isnt as sharp but still seems present. If you handed this to me and didn't say what it was, I'd think it was an ok Porter.

My suspicion now is that it is primarily a water issue, likely compounded by my input such as minor oxidation, infection, or temperature during fermentation(I usually run cool but this might mute some yeast flavors I suspect). Going forward I'm going to continue using RO or at least dilute. I'm starting a pilsner tomorrow, this should be another good test.

Thanks so much for everyone's input!

 

[FromZwolle]

that's great news!