Getting SG right in extract brews

[Crawfordid]

I imagine this has been discussed a lot before but appreciate any help.
Im fairly new to extract brewing but have done a few partial mash recipes now and never seem to get the SG that they reccomend,
I did a blue moon clone earlier today and should have been 1.054 but got 1.050. and recently my innis and gunn clone should have been 1.064 but got 1.054.

Method wise i did the partial mash in about 10 litres of water with about 1.5kg of grain (in a grain bag) at 66 degrees celcius, then washed the grains with another 5 litres at 77 degrees. then added the extract malt and added water up to 25 litres for the boil and boiled for an hour before ending up with about 20 litres before making up to 5gal in fermenter. The original recipe called for mashing with only 4.5 litres and washing with another 4.5 litres and then making up to 15 litres for the boil. My boiler uses an element though and needs to be covered with water which is why i used 10 litres and Ive read that you should boil with the most amount of water as possible to get the best flavour out to the hops.

So two questions really, will the different volumes of water make much difference in extracting the right flavour and is there anything in the steps that i have done to get more out of the grains etc to get the right SG

 

[cheapbrew]

How long did you mash for? maybe try a longer mash next time

But for water to grain ratio, see,

QUOTE:
The thickness of the mash doesn't seem to effect the fermentability of the wort that is produced but thinner mashes can significantly improve the conversion efficiency. As a result brewers who see low efficiency from their mashing may try to use a thinner mash (3-4 l/kg or 1.5 - 2 qt/lb) as they were shown to convert more starches.
ENDQUOTE

SOURCE: http://www.braukaiser.com/wiki/inde...e_infusion_mashing&redirect=no#Mash_thickness

http://www.braukaiser.com/wiki/index.php?title=The_Theory_of_Mashing#Mash_pH_targets

 

[Covrich]

I am a bit confused, when you say extract do seem to describe All grain and mashing?

Extract brewing is using... plain extract in which case you should get pretty much spot on the OG..

Don't have any make up water for the volume, split all the water you need for mashing and sparging, take into account grain absorbtion and boil evap.. so in essence for say a 23l brew you need around 32l of water overall and a 10 liter brew will need around 15.

 

[MyQul]

I am a bit confused, when you say extract do seem to describe All grain and mashing?

Extract brewing is using... plain extract in which case you should get pretty much spot on the OG..

Don't have any make up water for the volume, split all the water you need for mashing and sparging, take into account grain absorbtion and boil evap.. so in essence for say a 23l brew you need around 32l of water overall and a 10 liter brew will need around 15.

I think the OP is partial mash brewing where you mash for some of your wort but then add extract for the rest of your wort/OG (giving the benefit of being able to use those grains that can only be mashed) rather than pure extract brewing.

@theOP How are you "washing" (sparging) your grain? Are you simply pouring the water over the grain bag? If you are try dunk sparging where you put the grain bag in a bucket and pour the sparge water into the bucket. Then agitate the grain by stirring and lifting the bag repeatedly to get as much sugars off the grain.

 

[Spapro]

During the mash are you giving the grains room to 'float' ? Ie. you aren't tying your bag tight. You want the mash water to be able to fully permeate in and between the grains. Worth stirring the grains a couple of times during the mash.

As per MyQul, when 'sparging' you are trying to wash the sugars off the grain, so pour your kettle water through the grain, with the bag kindof opened and sat in a spare FV, then let things sit for a bit, and squeeze the bag to squeeze out as much sugary water as possible. Get some thickish marigold type gloves so you don't burn your hands when squeezing the grain bag out.

Clearly you are thinking about what you are doing and doesn't sound like you are doing a lot wrong to me.

Oh, and are your scales correct ? are you using the correct amount of grain as per your recipe ?

 

[Simonh82]

What grains are you using for the mash? If you are using lots of speciality malts to give you sweetness/flavour/colour then you may not have the diastatic power in your malt to convert the starches in the grain to fermentable sugars.

I don't know enough about it really but if it was mostly or all speciality malts you may not have enough diastatic power in the mash to get good efficiency from the grain.

 

[Crawfordid]

Thanks for the help guys

@cheapbrew - I mashed for 60 minutes and thanks for the quote, the concern I had was that by increasing the volume I may be extracting the incorrect ratios or undesirable flavours from the grains of that makes sense! But what you have said seems to make sense

@myqul and @spapro - you're right it's not 'pure extract' brewing but most of the interesting recipes seem to involve some sort of partial mash to be able to use more types of grains and get different flavours, I like the idea of dunking the bag in and out more and sparging better, when it comes to squeezing the bag after do you run a risk of extracting flavours /undesirables from the grains as I'll definitely get more sugars from that but sure I've read somewhere that you risk getting bad flavours from the grains ? I don't know how true this is though

@covrich - unfortunately my boiler can only take a maximum of about 27 litres at a push without making a mess, does adding extra water at the end change much? As I know it won't have the sugars in it but unless I've saturated the water in the boil with sugars which with that volume should hopefully be unlikely then won't they just redistribute into the new water or have I got this wrong?

Thanks
Innes

 

[Crawfordid]

@simonh82 I don't really know a lot about this, with regards to diastatic power etc, is there somewhere you'd reccomend reading about this? I'm only using about 1.5 kg of specialty grains in most of the partial mash recipes I've been using with about 3 kg of extract malt

 

[terrym]

@simonh82 I don't really know a lot about this, with regards to diastatic power etc, is there somewhere you'd reccomend reading about this? I'm only using about 1.5 kg of specialty grains in most of the partial mash recipes I've been using with about 3 kg of extract malt

In short 'diastase' is the generic name that covers a group of naturally occurring enzymes that are present in malted barley. Under the right set of conditions i.e typically when mashing malt grains in a slurry with water at about 65*C, the diastatic enzymes (diastase) if present will convert starches in the malted barley into fermentable sugars. However when malted barley is progressively kilned to produce different types of malt the diastase is destroyed in increasing amounts. Pale malt contains the most diastase and crystal malt, and onwards, contains none. You used to be able to buy liquid malt extract with diastase (typically Edme DMS) but this is now almost unobtainable in the UK.
So for mashing to work and fermentable sugars to be produced from malted barley starch there has to be a diastase containing grain present.
Hope I've got it right

 

[steveshep8676]

Hi Crawford, I've posted answers on this subject before so excuse me if you read it before but this is what I wrote in another post on the same subject. I hope this is of some help,

Hitting Target Gravity

Evaluate the total gravity during the brewing process and use it as a guide in adjusting the wort to the exact gravity you want. Remember that total gravity is the product of wort volume multiplied by its measured gravity in gravity units. As an equation, it is stated thus:
Total gravity = GU × Volume gallons

An important characteristic of total gravity is that it doesn’t change as you boil or dilute your wort. The only way to change the total gravity is to add fermentable materials such as malt extract, honey, or sugar to the wort.

By knowing the volume and gravity of the starting wort and the expected final volume of the boil, you can tell what the gravity of the wort will be at the end of the boil. Thus:

Total gravity (beg. of boil) - Total gravity (end of boil)

Because this is true, you can also say that

GU (beg.) × Volume (beg.) = GU (end) × Volume (end)

This restates total gravity in terms of the factors that determine it. If you now divide both sides of this equation by volume (end), you get an equation for estimating the final gravity of the brew. Thus:

GU (beg.) x Volume (beg.) = GU (end)
Volume (end

Say you have 8 gallons of runoff from the mash. The specific gravity of this wort is 1.038. You plan to boil long enough to yield 5.5 gallons of finished beer. Because the total gravity will not change during the boil, you can calculate the finishing gravity of the boil:
(38 GU × 8 gallons) ÷ 5.5 gallons 55.3 GU

This calculation tells you that this wort will have a gravity of 1.055 when boiled down to 5.5 gallons.
------------------------------------------------------------------------

In this example, I have set the terms “beginning” and “end” according to a specific brewing process that starts with excess volume and reduces it during the boil.

If you begin your boil with 4 gallons of wort with a specific gravity of 1.060, what will the specific gravity of the wort be once it is added to the fermenter and diluted to 5 gallons?
Use the same equation: [GU (beg) × Volume (beg) ] * Volume (end) = GU (end) but define “beginning” as the conditions in the boil pot and “end” as those in the fermenter.
Thus [60 × 4] ÷ 5 = 48 GU or 1.048

(60SG X 4gallon) ÷ 5 gallon = 48GU (1048)

 

[Simonh82]

I read about it in this article http://beersmith.com/blog/2010/01/04/diastatic-power-and-mashing-your-beer/.

I'm interested to hear you say you don't think you can do all grain in your boiler if it holds 27L. I've got a 30L Burco boiler which can boil about 27-28L and I can manage a 23L brew without extract by sparging the grains and then using this to top up the boil a couple of times.

I definitely squeeze the crap out of my bag and haven't noticed anything bad happen. I use some large extra thick washing up gloves with a pair of thin wool gloves inside. This allows me to grip and squeeze the bag easily.

 

[Spapro]

@myqul and @spapro - you're right it's not 'pure extract' brewing but most of the interesting recipes seem to involve some sort of partial mash to be able to use more types of grains and get different flavours, I like the idea of dunking the bag in and out more and sparging better, when it comes to squeezing the bag after do you run a risk of extracting flavours /undesirables from the grains as I'll definitely get more sugars from that but sure I've read somewhere that you risk getting bad flavours from the grains ? I don't know how true this is though

Work on the sparge and squeeze the bag ! Don't worry about off flavours, I squeeze the bag, sure I've read that off flavours and tannins etc are a result of chemical not physical over sparging - eg too high a temp etc. I did a good number of partial mashes (half extract, half grain) before moving to all grain BIAB.

I suspect thats your answer right there, work on the sparge and squeeze the bag.

I wouldn't change much else and see how you get on next time.

 

[cheapbrew]

What speciality grain was the 1.5kg?

 

[Crawfordid]

thanks for all the help guys appreciate it, never realised how much maths was involved in all of this until recently! and will squeeze and sparge away

@cheapbrew - grains used were 500 pilsner malt, 500g wheat malt, 500 g of flaked oats

 

[Simonh82]

That's a lot of oats. I used oats in my last brew at about 8% if the total gains.

Oats don't have any diastatic power so you would be relying on the pilsner malt to convert the starches to sugar. My understanding is that to do this effectively you need to make the starches available by boiling them for 10 minutes before they are mashed.

For my last beer I basically made a large saucepan of porridge and chucked it in with the other grains. Without this step I think you won't get much out of them.

I believe quick cook oats and possibly rolled oats have had this gelatinisation process take place during their manufacturer but it is probably better to cook them anyway.

 

[terrym]

grains used were 500 pilsner malt, 500g wheat malt, 500 g of flaked oats

Both malts contain diastase, little or none in the oats.
I assume that diastase will work on the starch in oats, just like it does on Torrified Wheat which is what I use in small quantities mashed with Pale Malt.

 

[cheapbrew]

The pilsner and wheat malts should have enough enzymes to work on the oats, so as mentioned dunk sparging and squeezing might improve things, and maybe try soaking the oats first as a porridge.