Question about Classic Styles' Conversion from 7 gal to 3.5 gal partial

[tmk]

I recently put the APA from Classic Styles in the fermenter. The recipe is on page 134. I followed his instructions for the conversion from 7 gal to 3 gal partial boil on page 37. I ended up putting about 4.5 lbs of extract in the boil. The original, 7 gal recipe, calls for about 9 gallons. The OG ended up at 1.048 and the target is 1.056.

On other other threads I've seen the suggestion of reducing the extract to 5/7 of the original amount. That would equate to about 6.5 lbs.

Any thoughts as to why my OG ended up too low? My initial conclusion is to use more extract, closer to the 6.5 lbs. That would indicate an error in the book, which I would be surprised about.

Thanks

 

[ncbrewer]

Using extract, you can't miss your target OG, assuming you got the total volume and pounds of extract right. Since this was a partial boil, it probably wasn't mixed thoroughly with the top-off water. That can give you a gravity sample either higher or lower than actual, depending on the sequence you used for adding wort and water, and how you pulled the sample.

 

[tmk]

Thanks for your response. We mixed the wort thoroughly before taking a sample.

As you stated, the pounds of extract to total volume is the critical element. I've seen two different recommendations when reducing a 7 gal boil to a 3 gal partial and the one by the expert didn't work for me. I plan on adding more extract the next time, following the 5/7 recommendation.

I just can't believe that Classic Styles was wrong -- I can't find a calculation error on my side.

 

[taalhiker]

I thought all recipes in this book are for 6 gallon batches.

 

[SandstoneCityBrew]

I thought all recipes in this book are for 6 gallon batches.

The book refers to 7 gallon pre boil volume, 6 gallons at the end of the boil, 5.5 going into the fermenter, and 5 going into bottles/keg.

 

[chickypad]

I can't quite tell if you are doing the 6 gallon recipe with a partial boil or if you're converting the recipe from a 6 gallon to a 3 gallon batch size. Exactly how much total extract did you add and what is your batch volume? As others said, extract gives a known amount of sugar per lb so if the measurement is off it's usually due to topping off and trying to mix or volume error.

 

[tmk]

I don't have any concerns about our taking of the SG.

I'm intending to convert it to a 5 gallon batch size, using a 3 gallon partial boil and then diluting to a 5 gallon batch. I understood his section starting on p 34 (Converting a Recipe to a Partial Boil). As indicated in a couple posts, I agree that the issue is that I'm not using enough extract.

Looking again at the problem and the responses, I think I'll just try the recipe again without modifications. I'm only moving from 5.5 gallons going into the fermenter to 5 gallons going into the fermenter. My questions are:

1) How should I adjust the grain bill, if at all, to compensate from a 5.5 gallons recipe to a 5 gallon recipe (going into the fermenter?

2) Should I make different adjustments (timing or quantity) because I'm doing a partial boil? I've heard a lot of people suggesting to only boil some extract and add the rest near the end of the boil.

3) Suggestions on how to calculate the OG from the amount of extract? I haven't looked through a couple books I have yet, but if someone has pointers, that'd be great too.

 

[chickypad]

1) you just multiply your batch size/recipe batch size for all ingredients to scale a recipe.
2) In the book Jamil goes into great detail about how to get the boil wort similar composition to the final wort, which is nice but seems like a lot of work to me. I would just boil about 1/3 to 1/2 your extract then add the rest late. The idea is you don't want to be boiling a super concentrated wort.
3) Most LME is about 36 ppg, DME about 44-45. That recipe is using LME and has an OG of 1.056. So for 5 gallon you need 56 x 5 = 280 gravity pts. 280/36 = about 7.75 lb LME total for the recipe.

 

[tmk]

That makes a lot of sense. I just found the explanation in Palmer's book as well. I've been meaning to reread that.

What is the problem with boiling a super concentrated wort?

Why even add the extract at the beginning of the boil at all? I assume that there is a hop interaction.

Thanks again.

 

[chickypad]

The main reason to add extract later that I see has to do with unwanted darkening/over caramelization of the wort. There was also a concern about decreasing hop utilization with too high a wort concentration, although as I understand it that seems to be much less of an effect than thought. Traditional thinking also is that some sugars need to be present for proper hop utilization, although if you search the Brewing Radio archives the guys did an experiment where the compared an extract batch brewed regularly to one where they boiled hops in plain water and added all the extract later. They both liked the plain boiled water version better. So who knows. Most folks don't boil plain water, but a small portion of the extract.

 

[tmk]

Thanks a lot for your help. The beer tasted good going into the secondary. Our 6th batch.