How to tell when conversion is complete

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David Woods

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The last couple of A/G beers have been disappointing, they have been weak, low FG and low carbonation. I am brewing all grain kits so I am assuming the ingredient quantities are correct and I am keeping very close to the temps and timings. My feeling is that I am going to the boil before conversion is properly completed leaving me with a lot of non fermentable stuff hence low FG and carbonation I batch carb with the same quantities I have used before with no issues but these last couple of brews have been poor - still drinkable but could do a lot better!

As I am still very new to A/G brewing is there a good fool proof way of determining that I have converted properly and got all the good fermentable stuff possible? would mashing longer help? I am not getting too high with the mash temp so not sure what I can do to improve things.

I am using a Brew Monk 30 all in one. If anything the sparge water temp may be a bit low.

Any help would be great.
 
I initially read the title as “when conversation is over” which in our house is when the missus has stopped talking.

Seriously, though…. By low FG I assume you mean high FG or low OG ?
Are you hitting pre boil gravity ?

Carbonation depends on the amount of sugar you put in the bottle or barrel and is independent of the FG of the beer.
 
what temp is mash at
How long.
Do you re-circulate with the pump during mash
Are you mixing in the grains well so no dough balls which will not convert fully if so
Iodine test is the way to check for full conversion
Are the brews different styles and what yeast and temp do you ferment at
Answer these and we will all be able to be more accurate in our assessments to helpathumb..
 
Sorry not paying attention! Yes the OG is low - 1041 instead of the expected 1048 and I even brewed at 23l instead of 25l in the recipe. The pre boil gravity seemed OK - using a refractometer.
 
Last edited:
Mash temp for this recipe is 66c, time is 60 mins, yes to recirculating, no dough balls - very careful about that.

Similar styles - amber ales, yeast temps as per the included yeast, around 21 deg. Fermenting is in a temp controlled fridge - I am usually within 1/2 deg.
 
Interestingly my first all grain was excellent - even though I had a complete Horlicks when the all in one stopped working! the mash must have gone on way too long and the temp dropped away but the beer was great! :confused:
 
What is your total water volume, and your pre boil volume, i am assuming you use an aio and sparge, as a for instance a 21L batch in my brewzilla, total water is 28.5L my pre boil volume is 25.92L that is for 4.5L of grain
 
We
Mash temp for this recipe is 66c, time is 60 mins, yes to recirculating, no dough balls - very careful about that.

Similar styles - amber ales, yeast temps as per the included yeast, around 21 deg. Fermenting is in a temp controlled fridge - I am usually within 1/2 deg.
Hi everything seems to check there David is it all fresh grains that you have used?
Have you got any Iodine to do a conversion check, it is quite simple to do and if that checks out it means the mash is not the culprit, if you have never done one just search Youtube as it is easier to watch and see what to do.
Are these your own recipe's or bought AG kits as it maybe something to do with too many adjuncts or grains with low Diastatic power which can cause low conversion
 
The kits are fresh from GetErBrewed - I make them as soon as I get them so hopefully very fresh. The kit is very basic - two types of grain, yeast and hops. As I am new I am keeping it very simple. No adjuncts in them.

I know it's me but trying to find the issue.
 
I know it seems like a thousand questions but we will eventually get there between all the members in the forum. We have all been there
 
Recipe for this kit was:

Best Ale Malt 4.1kg
Cara Gold 0.54 kg
Williamette & Challenger hops
Lallemand Windsor ale yeast
Mash temp 66c
Target vol 25l (I made it to 23l)
Mash time 60min - Boil 60min
I also did a whirlpool for 15 mins
Basic water treatment for ph etc - ph was bang on 5.2
 
Should also say that this brew fermented very quickly - 2.5 days which leads me to think there were just not enough fermentables in it.
 
One thing that pops out if I am correct id the Windsor yeast Which I am sure some other members may correct but is it not the one than attenuates low so gives a higher finishing gravity
Edit
Depending on the composition of the recipe, Windsor demonstrates moderate attenuation which will leave a relatively high gravity (density). Recommended fermentation temperature range for Windsor is 17° to 21°C (64° to 70°F).
 
Both brews that ended up thin with a low abv and carbonation were with Lallemand yeast - the brew with US-05 was fine.... I wonder
 
OK, so iwith a slightly lower OG, and a slightly higher FG, you would expect a lower overall ABV.

Windsor can finish high (it cannot metabolise all of the sugar types in wort) so perhaps try a different yeast with the same kit and see how you get on?
 
Sorry not paying attention! Yes the OG is low - 1041 instead of the expected 1048 and I even brewed at 23l instead of 25l in the recipe. The pre boil gravity seemed OK - using a refractometer.
The grain crush can make quite a difference in the OG. By doubling milling a bitter grainbill I got an OG of 1.040 instead of the expected 1.035.
 

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