Raising gravity in the fermenter

[jack_c]

I completed by first AG yesterday (a Kernel Pale Ale clone, recipe from viewtopic.php?f=5&t=69876) - modified the recipe to used Simcoe (and have some Citra for dry hopping).

Kernel Pale Ale
og 1.052
50 IBU
96% MO
2% carapils
2% caragold
Simcoe FWH 20 IBU
Simcoe 20 Mins 9 ibu
Simcoe 15 mins 9 ibu
Simcoe 10 mins 7.5 ibu
Simcoe 5 mins 5 ibu

All went well - nicely surprised how well the BIABacus estimated volumes and I ended up with my target of 23l for the fermenter. However, I was aiming for a gravity of 1.055 and have got 1.046. I didn't plan ahead for a lower gravity and had no malt extract to raise it, so I pitched and the fermenter is nicely bubbling away.

If I wanted to raise the Gravity up to my target of 1.055 what options do I have? Anyone have any thoughts on the following ideas? As this is my first AG, just thinking and hoping people with more experience can help.

1) Adding sugar to the fermenter after the Krausen has fallen
How much would I need to add?
Would this amount affect flavour / body? I don't need to raise it by much...

2) Add DME / LME to the fermenter
How much would I need to add?
Any flavour issues?

3) Add dextrose / maltose to the fermenter
How much would I need to add?
Any flavour issues?

4) Leave it alone
The gravity difference is only going to relate to t 4.8% / 5.5% ABV, maybe not worth mucking with it?

Probably going to just leave it but interested on your thoughts anyhow...

Cheers
Jack

[oz11]

As it's your first AG I would leave it alone and let it ferment out. An OG of 1.046 will still give you a decent beer. Mucking around now only gives you more opportunity to stuff it up.

Your percentages in the grain bill aren't meaningful without the actual quantities used and the volume of liquor used. You missed your OG this time, but put up your full recipe and we can see what happened that caused a lower OG. Everyone's set up is different.

[Rick_UK]

I would leave it but adding more fermentables to the FV would work - many recipes include sugar additions. Just make sure you boil the sugar in water before adding at this stage. Large quantities of refined sugars do tend to dry beers out though.

Rick

[Dave S]

+1 for leaving it alone. As Oz said, if you start mucking around with it now, that'a what you're doing - mucking around. And again, as Oz said, 1046 is a respectable strength, though you might find it slightly over-hopped.

[fisherman]

As oz 1046 a nice beer strenth.

[jack_c]

I think the missed OG was due to fluctuating temps during Mashing (this is a BIAB brew using a 40L Buffalo boiler). I had one too many beers during the day and forgot to check the Mash temp until 35 mins in...

My log shows:

16:10 67C, add bag and start to dough in
16:20 Dough in complete, 65C temp, wrapped boiler
16:55 Temp 62C, remove bag / place in fermenter, turn on boiler
17:10 Temp 67C, add bag, wrap boiler
17:30 Bag out, Temp 63C, Turn on boiler, add FWH
18:09 Rolling boil

Between 17:30 and 18:09 I recovered maybe 2 litres from the bag and added this to the boiler. For the 15 mins the bag was out of the boiler, its temp didn't drop below 61 (judged by placing the thermometer in the grain)...

Recipe:
5,900g MO
123g Carapils
123g Caragold

FWH 16.3g Simcoe @ 13.4%AA
20mins 12.2g Simcoe @ 13.4%AA
15mins 14.8g Simcoe @ 13.4%AA
10mins 17g Simcoe @ 13.4%AA
5mins 20.5g Simcoe @ 13.4%AA

35 litres ashbeck spring
70 min mash (between 63C / 67c, majority at 63c to 65c)
60 minute boil
30 min cool time (immersion chiller)
23 litres into fermenter
pitched 11.5g US-05

From my understanding, my Mash temps were under target (but not too low) and I'm now concerned I'll end up with a thin beer with little body (or worse case watery) and it be a touch over hopped. The temp range is right in the sweet spot for Beta amylase (54-65C) and a bit too low for Alpha amylase (68-75C), so there will be a load of highly fermentable sugars and minimal complex sugars.

I guess there's no way of knowing until primary fermentation is nearly done and I can taste it while checking gravity (between 14 and 20 days from now). If this is the case, I've read I can add Maltodextrin right up to the priming stage to add body. Or I could risk it and add some Malt Extract now / during fermentation. Any thoughts on this?

I'm probably just over thinking this and need to wait and see however still interested in any thoughts or advice you may have about this...

[simmyb]

Personally, I would leave AG1 to do it's thing (it might be a cracking drop as it is...) and get AG2 on. The more you do, the better they will get. There's no substitute for experience...

[lord groan]

I agree with everyone else, leave it be, it'll still be a good beer. One thing though did you measure the og at 20c? If it wasn't at 20 then the reading will be wrong (assuming your hydrometer is one standardised on 20c) and will need correction, a warmer temp will show a lower og so if it was warmer you may not be as far off as you think

[IronBlue]

Yes, definitely leave it alone, it will be a good beer and you can drink more of it.

As others have said, get a second batch on ASAP and continue learning your 'setup' and what figures you can repeatedly produce.

No-one has mentioned Efficiency. This is the figure you set in your software to ensure you should get near the OG figure for that recipe with your equipment and methods. There are two key influences - the mash efficiency (for pre-boil SG), and control of volumes (particularly boil-off for post boil OG). You can put your mash results into any online calculator to compute the mash efficiency you got, then plug this figure into your recipe for the next beer (I use Beersmith and that increases the grain quantities etc. to compensate for the efficiency). You should also record the boil-off you actually got, and again plug these into your equipment profile and it will influence the recipe.

Going a SG point or two up or down is typical. But the variance you described can be tackled by changing the efficiency setting. 'Total Efficiency'' can be confusing as it includes all the volumes through to bottling etc.. To get it right 'on the day' the mash efficiency and boil-off are the main influences - assuming your initial volumes (mash and sparge) are also correct.

Sorry for the egg-sucking waffle!

Edit: AS A GUIDE ONLY- THERE ARE A LOT OF INFLUENCES! If your volumes were correct, a 6-point reduction from 1.052 (in your original recipe) to 1.046 is about -8% total brewhouse efficiency. If your recipe had the typical default of 75%, changing it to 67% (which will increase the grain) would hit the figures you need if you did everything the same again. Don't worry, the 75% default is pretty damn high, I operate around 72% total but started a lot lower...

[Fil]

i also agree leave alone, the first few brews will feedback vital info such as the actual boil off rate, and once you have the mash sorted the actual brewery efficiency.. and as long as the final product has more than 3% abv its beer that will keep and its the beers that dont quite go to plan than can mature into the spectacular results every now n then..

imho the time to correct (if at all) is in the kettle, a gravity reading can be taken fairly soon after taking a sample if chilled in a pan of cold water to 20C before adding the hydrometer (plastic trail jar) ..

insulating the boiler during the mash will help retain heat, and can if applied successfully negate the need for much heat input during the mash.

enjoy sampling

[jack_c]

You are all right - leaving well alone is certainly best, just over thinking things and wanting to get everything perfect first time.

@LordGroan - I'd lowered the sample jar to 20c before testing the og, although good call.

@IronBlue - good advice, no waffle! This is my first batch with all new equipment with the calculator set with a default efficiency of 75%, which I'd not considered changing... I'd already adjusted some variables after a "dry" run (kettle to fermenter loss less than predicted, so I used less starting volume volume) and the brew went as predicted by the calculator. I've re-adjusted for 68% and will see how my next batch goes, keep measuring, recording and adjusting.

The next batch will be a Brew Dog IPA clone (similar recipe, although, more hops and a higher target gravity), so this should help me get a good feel for my kit.

I'll also be paying closer attention to temps during the mash, important lesson learnt - don't relax and have too many while brewing...

Thanks again all for the sound words, I'll let you know how it turns out