Using bare minimum of DME in partial mash

I have done about 4 partial mash beers and I do not have enough space in my loft for a complete all grain set up, so I am going to keep making PM for the foreseeable future. I use the stove-top method for my PM...

However, I want to make as close to an all grain batch as possible, using the bare minimum of DME to bring me up to the correct starting gravity.

Since most of the recipes I use get the majority of their fermentable sugars from the DME, how can I calculate the correct addition amounts without doing multiple batches and determining efficiency? Especially because it seems like it is hard to get constant efficiency with this method.

I believe that the most grain I can comfortably mash is about 4 lbs.

How big is your boil POT? Do you have another large one? You may could do a full or smaller size batch BIAB on the stove with no additional equipment and do a true AG batch.

I have 1 5 gallon pot and 2 2.5 gallon pots. I had considered doing exactly that but I had been using one as a mash and one as a sparge/boil.

Look at the recipe for old bog road brown ale in my pulldown I give variations of the pm recipe based on cooler size which changes the grain to extract ratios. You can get a rough idea of how to calculate it out.

Full all grain may not be as far from your reach as you might think. If you buy another 4-5 gallon pot you can do a split pot boil on the stove to boil the 6.5+ gallons needed. Also a mash tun can be made really easily for 5 gallon batches with coolers. You probably have a few bucket already that will help transfer liquid as well.

Thanks for the replies guys..

I guess what I am saying is that I cannot afford any more space for other brewing equipment, and I was looking for a way to calculate how much DME to add to make up for my lack of mashing ability.

I have mashed 4 lbs before in a mini mash with no problem, but that appears to be the limits of my pots, and that is not even doing a full boil, but a split one.

I do not plan on making a lauter tun or any other such tool in the neat future, just BIAB.

I was wondering if there was some way to calculate how much to add for any given recipe.

My guess would be assume a given efficiency of 60-65%, calculate the OG of the wort from the grains and add the remaining DME to make up the difference for the boil then water back or boil longer as necessary?

My problem is I am not that good at calculating this type of thing, would beersmith or some other type of calculation program be able to help with this?

I've done about 10# for an ag batch in a 5 gallon pot. You can easily do an ag batch if you like.

I'm new at this so take this in that context.

Couldn't you do your mini mash and then take the specific gravity and adjust for the temperature. That would tell you exactly how many points you needed to make up with DME or other fermentables? Which would have the benefit of giving you an accurate measurement of your conversion efficiency. I mean once you know the SG and the volume of wort and the volume you're going to end up with figuring how much you need to add is just a little basic algebra.

DME has a PPG of approximately 44 meaning if you put one lb in one gallon you'd end up with a OG of 1.044.

So here's what you do, use this chart to determine the total points you're getting from your partial mash grain http://www.howtobrew.com/section2/chapter12-4-1.html. With BIAB you're efficiency is going to be fairly low, probably 65-75% so multiply the PPG from the grain by your estimated efficiency.

Say you're shooting for 5 gallons wort with an OG of 1.050. You need 250 total points. Say you mash 4lb of 2 row (148 maximum points) and you think you'll get 70% efficiency. So you will actually get roughly 104 points from your grain.

So to get the 250 total points you need subtract the estimated points from the grain and you know you need a 146 point boost. Divide this by 44 PPG from the DME and you get 3.32 pounds. You do not have to account for efficiency as DME is fully converted into points.

Hope this helps.

zanemoseley said:

DME has a PPG of approximately 44 meaning if you put one lb in one gallon you'd end up with a OG of 1.044.

So here's what you do, use this chart to determine the total points you're getting from your partial mash grain http://www.howtobrew.com/section2/chapter12-4-1.html. With BIAB you're efficiency is going to be fairly low, probably 65-75% so multiply the PPG from the grain by your estimated efficiency.

Say you're shooting for 5 gallons wort with an OG of 1.050. You need 250 total points. Say you mash 4lb of 2 row (148 maximum points) and you think you'll get 70% efficiency. So you will actually get roughly 104 points from your grain.

So to get the 250 total points you need subtract the estimated points from the grain and you know you need a 146 point boost. Divide this by 44 PPG from the DME and you get 3.32 pounds. You do not have to account for efficiency as DME is fully converted into points.

Hope this helps.

Click to expand...

This here is what you want. DME has a known gravity per pound per gallon, and you can always add your DME in the last 15 minutes of the boil, after you've taken a gravity reading of your mashed wort.

You'd really benefit from a refractometer in this situation...taking 3 drops of wort, cooling it in 30 seconds, and taking a reading would give you what you needed to know for that late extract addition. A hydrometer reading would be cumbersome.

This is exactly the type of information i was looking for.

Thanks!

The less math I need to do the better!

avidhomebrewer - how did you fit 10# into a 5 gallon pot? What did you use for the sparge and/or boil?

I like to take all grain recipes and convert them to my partial mash system. I use Beersmith and then do the conversion so that I basically end up with a smaller all grain batch that just fits my boil kettle, then it calculates how much extract I need to add to exactly offset my top up water.

I did a write up on how I like to do it, step by step in Beersmith, and can find it and post the link if you want it. I wrote it up using LME for the extract, but you can probably do the same with DME.

If you have a chance to post that link, that would be great...thanks!

Here you go: https://www.homebrewtalk.com/f12/converting-recipes-partial-mash-partial-boil-beer-smith-142244/