So, who's done a sour mash?

So, I've been wanting to brew a little Berliner Weisse for a while. Small, light, crisp, tart, summer beer. Even bought a lacto culture a couple years back, but never got around to. A little intro into sour beer-making for me.

I kind of don't like the idea of the lacto running wild in a fermenter, though, even though I know that I can totally re-sanitize glass, it's totally illogical.

But, cleaning up the other day and I found my old 5-gallon mash tun. Got to thinking... why not try doing a sour mash? So, I'm putting the tun back together, I already had most of the parts anyway, and that'll be my dedicated sour-mash MLT. Do the souring first, then boil to kill the critters and ferment out the remaining sugars with US-05 or some other traditional beer yeast.

So I understand the basics of the process, and I know there's a huge amount of variability. I'm just going to try a few 3 gallon batches to start. My questions:

1. OK, so mash in at around 110°-120°, let it sit for a while. How long's a "while"? Overnight? One day? Two days?

2. Once that phase is done, do I need to raise the mash temp up to sac-rest temps (150°-ish)? Will there still be unconverted starches? Do I still need to do a "normal" mash after the sour mash?

3. Most BW recipes call for a short boil (10 minute). Can you still do that short a boil with a sour mash, or do you need a longer boil to drive off any unwanted funky compounds?

What else has been successful for people? Other tips?

1) Sour mashes usually go at least overnight, but I know a couple people who've gone past 48 hours to get it nice and sour. Make sure you taste it.

2) As I understand it, you do the regular mash before hand, take it to mash-out temperature to denature all the enzymes, let it cool down, then add some dry grain in to add the lacto critters. If there's no sugar in there for them to eat they can't really do too much souring.

3) You can do that short of a boil, but when I did it that short I got an absolute ton of DMS from the Pilsner malt. It mellowed out (after almost a year) and it's surprisingly a pretty good beer now, but if I do it again, I'd boil at least 60. The only reason to do a short boil is if you're following tradition, which I wasn't (and you aren't), so don't worry about that part.

i have not done a 100% mash, but my next beer will be a berliner w/ a 100% mash at 48 hours for and also pitch lacto in secondary (i'm going for bracingly sour as this will ultimately be a blending beer with three separate yeast pitches)... i'm also planning on a short boil (10 min)

the ones i've done have been between 0.5 lb and 2 lb of grain anywhere from 2 to 4 days (up to 20% of the grain bill only so far). mash in, mash out, (i would recommend adding more water than you typically mash in at as the grain really absorbs a lot of water over a few days - but you can always add water to the sour mash as well). let it cool to 110 or so, pitch a bit of raw malt (i use acidulated malt just to jump start it) stir, seal, keep it there, and do not let it get above 120 (fatal to lacto).

don't stir, don't open it to smell (you'll smell it, don't worry... lol) and leave it be... i used a heating pad under the container and wrapped it up tight in towels. had a remote thermometer in there so i always knew the temp. mine ebbs and flows between 90 and 115...

works well but its a PITA.

right now i'm trying to culture my own lacto so i don't have to do this all the time. we'll see how it works... almost settled on a lacto culture recipe.

and it should smell sour, but not bad... you'll recognize the smell.. i haven't had any off flavors/aromas from it yet but i'm sure its possible, its a ripe environment for bacteria obviously.

i can tell you that you'll get a nice white crust on top of it if you nail it... O2 will oxidize it and turn it gray..

So are people only doing the sour mash for PART of the grain bill? I woulda thunk the whole thing, especially considering something like a BW isn't going to have a lot of grain anyway.

not having done a full mash, i think i'll prefer the partial sour. easier to control the variables - finding a way to keep a constant temp throughout 8lbs is much harder than 2 lbs...

with the BW i'm doing next i'm using that exact logic - not a big grain bill and i'm pretty sure my set up should be able to keep my MT at 110 for 48 hours...

i think you can "get away" with only souring a portion of it - if you want it more sour, just keep it longer as it definitely gets ripe after 4 days. my house stunk so good...

Is there a reason that you have to keep the temperature significantly above ambient, though? The lacto will still work down at room temps, right? Do you try and keep it elevated just to speed up the process, or to keep other particular critters at bay?

Would it work to mash in a cooler at ~115°, close it up tight, maybe cover it with a bunch of blankets and just let it sit? Maybe re-infuse with a bit of fresh, hot water once or twice a day?

not sure to be honest, good question... i know that a fluctuation between 95-110 works tho - never tried to grow it at lower temps. there are a lot more bacteria that thrive in lower temps and i think the idea is to hit lacto's ideal temp keeping everything else at bay.

infusing with hot water works just fine - i've done that, but i've preferred adding more water to mash (1.5+ quarts per pound) and keep it warm... excuse the french but that **** sucks up liquid quick.

it makes intuitive sense that the more mash you sour the less time you have to sour it so if you could cool your mash down quick, i'd bet you could just hold the MT at 110 sealed in a cooler and be solid for a day or two which would probably be enough. mine have gone sour at about 18 hours and ramped up quick after 24 hours... the longest i've done is 48 hours with 2 lbs and probalby won't do it again (i have to work, right? lol)...

I did a full sour mash for a Kentucky common. I mashed in at 152-ish and just sealed it up for between 48-72 hours. When I got to it again it was room temperature and stanky.

It was definitely sour, but not the most sour thing I've ever had. The flavor would probably be right for a berliner weiss, that being said.

I have no room to talk here as a noob, but I was reading in a magazine that the higher temp encourages the bacterial growth.

The two berliners I've made I did a single decoction (135F->149F). Ran off about 5.5 gallons into my kettle, then ran 4gallons into a carboy, pitched US-05 once it was down around room temp. Ran off the other 1.5 gallons into a 2 gallon plastic bucket and added a half pound of uncrushed malt. Let it sit 12 days for one (very very very sour final brew) and 6 or 7 days for the other one (reasonably sour) before racking into the carboy. Bottled a week or two later.

I just did a sour mash experiment. Basically followed Papazian's sour mash process from Joy of Homebrewing. I took pictures, too...

1 gallon batch: brewed 3-6-11
OG ~1.045

1.5 lbs. 2-row
1 gram Chinook pellets (11.9% AA) - 20-25 mins in boil
0.1 lbs. crushed 2-row for bacteria

Used a little Coleman lunch cooler to mash and sour in:


So that little cooler and small amount of grain didn't work out the same way a full batch in my 5 gallon MLT usually does... so I ended up mashing at 130F for about 90 minutes. Brought up to 155F on the stove and transfered back into the cooler (2.5 qt/lb). 155F held until and iodine test confirmed conversion... maybe 30-40 minutes? Added cold tap water to cool mash to 125F. Stirred in 0.1 lbs. dry cracked grain and completely covered the surface of the mash with plastic wrap, and got all the air bubbles out:


Some time later... maybe ~15 hours:


Ended up being ~30 hours before I could sparge and boil. Plastic wrap swollen up, barely touching the surface now:


I didn't check the temp... was probably around 100F? Infused 1.5 gallons of boiling water and transfered to pre-heated 5 gallon cooler MLT.. this warmed it up to about 145F. Collected 1.5 gallons of wort and boiled down to about a gallon in 45 minutes. Chinook pellets last 20-25 minutes... I was shooting for ~10 IBU.




The taste pre-boil... got spit into the sink. Not bad, just.. unrefined. It smelled funky.. but I've read people say there's a 'vomit' character to a sour mash... I did not experience this. It had that clean, cool smell that yogurt has. The spent grain had a weird - different, I guess - texture. There was some.. mush.. in there after sparging. Maybe its from the accidental 90 minutes rest at 130F, maybe the bacteria.


Cooled the wort down to room temp in a bath in the sink. One day prior I made a 1 cup DME starter and pitched the dregs from a bottle of Victory's Wild Devil, hoping to do a 100% brettanomyces fermentation on this soured wort. There was no visible activity from the brett, so I decided to pitch some Danstar 'Windsor' Dry yeast also... I didn't want to open a $4 pack of US-05 and would probably not use the Windsor on a real batch:


Windsor took off in a ~8 hours:


Today (3-26-11) the beer is completely opaque. I'm new to the brett thing so I'm not really sure what to look for. There are a few bubbles on the surface of the beer, but if a regular 5 gallon batch looked like this one I would show no concern.

I took a gravity reading on 3-18-11 but forgot to write it down. 1.012 maybe? The beer wasn't bad. It was very tart, on the level of Ithaca's Brute.. not in complexity or character, just in level of pucker. I'm new to sour beers, and don't have much of a reference for taste.

Next batch will be 5 gallons of ~1.050 wheat beer, soured maybe 15-20 hours, and consumed in large quantities on hot summer days. The sour twang was very quenching, not unlike lemonade.