FG too low - 1.006?

I brewed an all-grain batch about two weeks ago. Wasn't seeing anymore airlock action, so I took a sample. The OG was 1.067 at about 66% efficiency. When I took a reading today, the gravity had gone down to 1.006.

This is the recipe I used:

11 lbs. Briess Pilsner Malt
3 lbs. Briess Munich Malt
1 lb. Weyermann Melanoidin
.5 lbs. Briess Crystal 20L
1 oz. Briess Chocolate Malt
1 oz. Nugget
.5 oz. Pacific Jade
.5 oz. Celeia
.5 oz. Pride of Ringwood
White Labs 001 California Ale Yeast

MASH (used a Rubbermaid Mashtun)
Grains = 70F, 19 Quarts Strike Water = 166F, Mash @ 152-154 for 1 hour then drain after vorlauf. Sparged in two batches approx. 8.5qts heated to 180 degrees with each sitting 15 minutes before vorlauf and drain. I used the brew365 calculator for the strike temps.

Boiled for 60min. chilled to 70F and pitched the yeast & starter into 5.5 gallons.

I'm planning on leaving it in the primary for another week then racking into the secondary and dry-hopping with 1oz. Amarillo before bottling.

I was aiming for a FG around 1.015 and I'm not sure what happened. I'm relatively new to AG (this isn't my first batch though), but I'd been doing partial-mash for a long time and extract before that and I've never experienced a final gravity this low before.

I know my sparge and mash were the same quantity of water, but that was due to lack of space in the brew kettle. The only other difference I can think of is that with this batch I used a starter by mixing 2 cups water with 1/2 cup DME and the yeast a day before brewing. It's the first time I used a starter. The fermentation temp also may have been a bit in the higher range reaching about 74-77 at times. I assured the hydrometer was calibrated and took readings at the correct temperature. I guess it's possible my thermometer reading could be off and maybe the mash temperature wasn't as accurate as I thought so I'm planning on double-checking the thermometer next. I didn't notice anything wrong though b/c when it hit boiling it appeared to be reading pretty accurately (sometimes at boiling it can be hard to tell with the condensation).

Any other suggestions as to what might have happened? The flavor is okay so far, but it does lack a bit of mouthfeel for a beer that is supposedly 7.99% ABV (if the FG was as accurate as I thought). With an IPA I think that a less than expected mouthfeel won't be too big a problem, but if there is something in my process I can correct for future batches I'd appreciate feedback. Thank you!

Check your hydrometer. Otherwise its just fine.

Usually, when you see a FG of under 1.010, it means a lower mash temperature, while a FG over 1.014 often means a higher mash temperature.

It's not a problem, but I"d double check the accuracy of your thermometer. It sounds like you mashed at more like 148-150 than 154.

I had this problem. For me the problem was I had to use the boil kettle for the sparge water and because I double batch sparged my first running a were sitting in a kettle still converting while I sparged. My wort was sitting there for probably half an hour until i was able to get it on the boil. Every batch would finish well below 1.010. I fixed it by getting an HLT so I could drain my first runnings into the BK and get the heat on the BK right away to stop conversion. You could also do a mash out, raise the temp of the grain bed to 168 to stop conversion that way.

phuff7129 said:

I had this problem. For me the problem was I had to use the boil kettle for the sparge water and because I double batch sparged my first running a were sitting in a kettle still converting while I sparged. My wort was sitting there for probably half an hour until i was able to get it on the boil. Every batch would finish well below 1.010. I fixed it by getting an HLT so I could drain my first runnings into the BK and get the heat on the BK right away to stop conversion. You could also do a mash out, raise the temp of the grain bed to 168 to stop conversion that way.

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Yes. It took me a few batches to see this hole in my process. Check your thermometer first and then look into this.

Thanks everybody, I think between the thermometer and the wort sitting while the second sparge happened, I'll be able to make some changes and upgrade some equipment (aka, buy a bigger kettle).

phuff7129 - Are you saying the first runnings can continue to convert after they've been collected? I only ask because I'm getting 1.006 FG's on almost all my beers. As a step to remedy this, I just replaced my thermometer.

I've been collecting my runnings in a bottling bucket that sits on a crate while my boil kettle heats up the sparge water. After collecting all the runnings I'll dump them into the boil kettle and heat them up.

I might have to buy another kettle to collect and heat up my first runnings.

Aside from having a light body and having a dry finish is there anything wrong with having a gravity so low? I just finished my first AG batch two weeks ago and OG dropped from 1.056 to 1.003! Sorry Drinky, not trying to take over your thread, just wondering, is there such a thing as too low?

My first AG batch had OG 1.051 and FG 1.006. It was an APA, but it tasted just like a Belgian Wit. I think it was contaminated with some wild yeast - probably Brett. Have you tasted yours yet?

pdm1982 said:

phuff7129 - Are you saying the first runnings can continue to convert after they've been collected? I only ask because I'm getting 1.006 FG's on almost all my beers. As a step to remedy this, I just replaced my thermometer.

I've been collecting my runnings in a bottling bucket that sits on a crate while my boil kettle heats up the sparge water. After collecting all the runnings I'll dump them into the boil kettle and heat them up.

I might have to buy another kettle to collect and heat up my first runnings.

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Conversion and wort ferementability are two different things. Alpha and Beta amylase convert long chain starches into sorter chain sugars. Once there is no starch left, conversion is complete. The enzymes will continue hacking the sugars apart until the go inactive by the temp falling too low, or denature due to higher heat (a simplified version).

In your case, the enzymes in the sweet wort would continue to chop the sugars in the first runnings into more ferementable sugars as they sit in your collections bucket. The enzymes aren't stuck on the grain. They will continue to work on drained wort until denatured by heat (Beta amylase denatures rapidly above 150, Alpha above 165 or 170).

That makes sense. That's great info; I was searching on here to see if anyone else could elaborate. I think that'll cover it for me. I'm asking Santa for a HLT.

pdm1982 said:

That makes sense. That's great info; I was searching on here to see if anyone else could elaborate. I think that'll cover it for me. I'm asking Santa for a HLT.

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Another alternative is you could also reduce your main mash time or mash higher.

If you know your system functions consistently for a given process then you can tweak individual variable of that process to yield different outcomes. It's not necessary that you have a 3 vessel batch sparge operation to achieve higher finishing gravities, just that you know how to manipulate your system to produce those results.

That being said, you should total ask Santa for some sweet new toys.

I did an extract brew a few weeks ago and got 1.006 when I transferred to secondary on Monday so I may cut the dry hopping a little short so the gravity doesn't keep dropping. Im also going to double check my hydrometer (hopefully santa brings me a refractometer). Will having a lower gravity affect carbonation in bottles? Or would adding a little more priming sugar be a good idea?

I suppose a mash out or a warmer mash would suffice but I'd prefer the HLT. It'll make first wort hopping easier too.


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BierGut said:

Aside from having a light body and having a dry finish is there anything wrong with having a gravity so low? I just finished my first AG batch two weeks ago and OG dropped from 1.056 to 1.003! Sorry Drinky, not trying to take over your thread, just wondering, is there such a thing as too low?

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If by means of process and / or equipment, you find yourself continuing to produce highly-attenuating beers, the "problem" could be that this dryness doesn't fit every style. For example, trying to make a sticky sweet Wee Heavy and ending up with it dry...

Right, I get that. Luckily Drinky and I brewed styles that won't be hurt by the drier finish and we also had the same issues with temp and first runnings waiting for the sparge that led to this "problem". This was my first batch with the new equipment so I guess it's just part of getting the system dialed in

Everything everyone else said... plus I've found that WLP001 is an attenuation champ. I recently got 82% attenuation. I've now read of people getting 85%. It is a yeast beast.

So, if you don't want high attenuation: mash warmer, get wort on flame while sparge is resting, use a different yeast strain.

kev211 said:

I did an extract brew a few weeks ago and got 1.006 when I transferred to secondary on Monday so I may cut the dry hopping a little short so the gravity doesn't keep dropping. Im also going to double check my hydrometer (hopefully santa brings me a refractometer). Will having a lower gravity affect carbonation in bottles? Or would adding a little more priming sugar be a good idea?

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if you're bottling, don't cut fermentation time short to prevent the gravity from dropping lower - it will just continue to ferment in the bottles and give you bottle bombs. Let it finish, then use the normal amount of sugar. Safety first.

ncbrewer said:

if you're bottling, don't cut fermentation time short to prevent the gravity from dropping lower - it will just continue to ferment in the bottles and give you bottle bombs. Let it finish, then use the normal amount of sugar. Safety first.

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Its held the same gravity the past two days, so Im gonna check tonight and cold crash it if its still the same. I was gonna try to let the hops sit in there for 7 days but it looks like it will be a 5 day dry hop