AG#13 VTM Pale Ale "Big Brew"

[matt76]

After some discussion in this thread i decided to have a crack at this.....

My normal brew size is about 11L (limited by my equipment) and yields 20 x 500ml bottles - the plan was simple, brew a stronger wort and then liquor back in the FV to a more sensible OG.

The trick here is that gravity scales linearly as you concentrate or dilute the wort, but due to the higher wort gravity the hop utilisation is different, so you can't just add more hops in proportion (well, you can, but your IBUs will be out). The trick (i think!) is to scale the IBU's, not the mass of hops added.

Recipe was a repeat of my AG#1 except aiming for an ABV around 4.0-4.5% instead of 6.2%! So I'm aiming for OG = 1.041 and 27IBU's.....

3.0kg MO + 300g FB
27g EKG @ 5.8% 60mins (34 IBU)
64g Fuggles @ 4.3% 5mins (12 IBU)
Wyeast 1275 Thames Valley

Mash 10L @ 62degC
Sparge 6L @ 80degC

Added 1L pre boil to bring me up to my usual volume of 15L - important as i can estimate boil off from experience, i normally go from 15L to 11.3 - 11.4L in 60mins.

BG 1.054 (15L)

Here's the science bit - I had worked out our in advance and I quickly recalculated this while waiting for the boil, once i knew the actual BG:
1. From the original recipe i know i want 27 IBUs (20 from the EKG and 7 from the Fuggles)
2. From experience i expect to have 11.35L post boil
3. Using Brewers Friend this boil off will give me 1.071
4. So after the boil I'll need to add 8L to get this down to 1.041, bringing me to 19.35L
5. 19.35L/11.35L = 1.7
6. 27IBU's x 1.7 = 46IBU's (actually you can work this out per each hop)
7. Now quickly fiddle the hop additions in Brewers Friend to get the required 46IBU's - after liquoring back this will be equivalent to the 27IBU's in the original recipe.

In the end i got OG 1.066 (11.6L) - boil off was a fraction less than normal so my hop additions are a tiny bit out, but only about 1-2IBU which I'll never notice.

Using Brewers Friend again i calculated i actually needed to liquor back with only 7L to get me down to 1.041 - in went the water, check the gravity, and..... 1.022, miles under, balls, how the flip did that happen!!!

Hang on - what's that you're saying, Brain? Grab the sacred giant brewing spoon? Aha! A good stir to get it all properly mixed, recheck, and..... 18.6L in the FV, bang on 1.041

In amongst all this fun i also bottled AG#12 - i needed to use a different (larger) FV to fit this brew but wanted to reuse the yeast cake so i actually used the extra water to swill out the old FV to add the yeast (Wyeast 1275) to the new one. Seems to be getting going already so fingers crossed!

 

[pilgrimhudd]

Well worked out! I'll be saving this page and copying your maths for my next brew tomorrow!

 

[matt76]

Update:

After 3 weeks in the FV it was time this evening to bottle this brew - to be honest I'm a little perplexed but we'll come to that.....

Gravity is down to 1.006 (somewhat lower than I'd expect although looking back at my notes when I brewed this first time round it went down to 1.008) so this gives me 4.5%, exactly where I wanted it.

About 20L in the FV but I expected to lose a bit to trub, so 120g table sugar dissolved in 300ml boiling water, should give me about 2.5 vols CO2.

First of all I filled and capped 20 x 500ml bottles, but for the remainder I had other plans to experiment a little..... this is more beer than I need so I decided I could afford to experiment a little, nothing ventured, nothing gained.....

Inspired by this article I decided to try adding some Earl Grey tea. I steeped 5 tea bags in 600ml boiling water for 3-4 mins then added it to the bottling bucket and stirred gently to mix. This yielded an additional 14 x 500ml bottles - let's wait and see how it turns out.

So why am I perplexed? Well this is a slightly lower strength version of something I've made before and I've used this yeast (Wyeast 1275 Thames Valley) a few times with good results. But in this case I'm really not sure about the look or taste - I'm used to my beer being unclear at bottling but this looks much murkier, really not at all clear or bright. The taste isn't bad or off but just not right.....

My first thought was it's like a witbier - weird because I used the same FV for a witbier 2 brews previous, but surely that's not possible. But then I realised I think it's a yeasty taste - for some reason the yeast hasn't settled out hence the beer looks murky and tastes yeasty.

I'm not sure what can be done about this - I don't have a brew fridge so I cant cold crash the whole FV anyway, but I wonder if this would have helped. I'm happy to wait it out and hope everything settles out during conditioning. But I would like to understand why it's happened so I can prevent it in the future.

My best guess is I didn't use fresh yeast - this yeast originally came from a fresh pack for AG#4, then I made a starter from harvested yeast for AG#12 and then for this brew I simply re-used the yeast cake from AG#12 (which has cleared nicely in the meantime incidentally). So I wonder if I've picked up a mutation or something so the least is now less flocculant.

Ah well, guess we'll see in a few weeks time.

 

[pilgrimhudd]

I don't fancy that Earl Grey stuff much! Glad to hear that it's gone ok. I also liquored back last week on an English IPA from GH's book from memory I was trying for an OG of 1060 something but only got 1030 so I wonder if I didn't stir it properly.....

I bottle it on the weekend so I guess i'll roughly be able to tell how strong or not it is then.

 

[matt76]

I just thought it was a good opportunity to experiment as it's a much bigger batch then I'd generally make.

I had an Earl Grey pale ale a couple of years back from Siren Craft Brewery down the road from me which was good as I recall.

It could work - bergamot is a citrus fruit after all, just a question whether it's better to do it with tea or bergamot oil.

But it's also got me thinking now whether herbal teas (the ones without any actual tea in them) would be any good for flavour additions - food for thought.....

Just wish I knew for sure why the beer's so damn cloudy

 

[matt76]

Well this is odd.....

I've been keeping an eye on the bottles as they condition.....

The "regular beer" ones are still cloudy but there already a thick layer of sediment at the bottom of the bottles, so given time I'm confident they'll clear ok.

But the ones where i spiked it with Earl Grey..... Well they're cloudy too but with very definite little globules where (I assume) the "stuff" has coagulated together. Again there's sediment at the bottom so I'm sure these will clear too. I'm just surprised (a) to see such a marked difference due only to the addition of tea and (b) to see such clearly discernable particles.