Homemade Pumpkin Beer

With the end of the year comes an abundance of fall produce such as squash and pumpkin. Grateful to have a large harvest of pumpkin this year from the Lyle Center, I decided to do something I’ve never done before: make a pumpkin ale.

The recipe I used is Charlie Papazian’s Pumpkin Ale. Other recipes were pretty similar; however, this one is on the high side in terms of adjuncts (non barley base ingredients) which is a plus due of the large quantity of pumpkin I had available.

For those who have not homebrewed before, I would not recommend this recipe as it involves a significant amount of specialized equipment and familiarity with the process. Although the steps are fairly straightforward, the process is lengthy and certain mistakes can lead to an entire batch being ruined which can be quite costly. There are many malt extract (unfermented beer concentrate) recipes available which require minimum investment in equipment. However, for those who are looking for something more challenging, the procedure I follow here (all grain brewing) opens up a world of possibilities in terms of control over the process and ingredients.

Ingredients (The following are modifications I made or options I chose):

Grains – I used 2 row Great Western Malt instead of the recommended 6 row. There is less diastatic power in 2 row but the calculation found here shows that there is plenty of diastatic power even with adjuncts composing half of the main mash ingredients

10 lb pumpkins

1 Tablespoon Vanilla Extract

Safale US-05 Ale Yeast I found at my local homebrew store

Equipment:

Baking Trays

Knife or Chopping Tool

10 lb scale

100g scale – or scale sensitive enough to measure ½ ounce

Grain Mill (optional – local homebrew stores usually have one available. Mine is a Monster Mill)

Brew Pot (10 gallon or larger)

Heat Source – straddling the brew pot over two burners on my cooking range is adequate for boiling the wort. Not all ranges produce enough heat so a propane burner or other heat source would be required.

Ladle/ Small Saucepan – for scooping grains and liquid from the brew pot to the lauter tun. I use a small saucepan because all my ladles are too small.

Lauter Tun (straining contraption I made by following the directions for the Zapap Lauter Tun)

Thermometer (I just use the one on the side of my Brew Pot)

Wort Chiller (bent copper tube that connects to a garden hose to chill the wort or unfermented beer)

Food Grade Vinyl Tubing – for transferring liquids from one container to another

Drilled Stopper/ Fermentation Lock – for connecting the blow off tube. A popular alternative is a fermentation lock. It is debatable whether it is necessary or not; I have left wort out to pick up wild yeast but the air turned out to be as sterile as a clean room. I have also let beers ferment with just a paper towel covering it without any problems with contamination but maybe it’s because I’m in Southern California.

Hydrometer – checks density of liquids. Used to determine alcohol content by calculating the difference.

Fermentation Vessel - mine is a PET carboy but any food safe bucket will do

Bleach & Containers for Sanitation – I dunk everything the unfermented and fermented beer comes in contact to prevent anything other than the intended yeast from fermenting the beer

Bucket – 5 gallon or larger, food grade

Bottles – new or cleaned used ones

Bottle Filler – mine has a spring which acts as a valve and only opens when pressed against a hard surface like the bottom of a bottle. It isn’t necessary as the spigot at the bottom of the bucket can be used to control the flow. Even the spigot isn’t necessary since a siphon can be started and the tube pinched when needed to stop the flow; however, I found the bottle filler handy in minimizing splashing of the beer which becomes sticky and hard to clean.

Bottle Capper – there are two designs: one with two handles that works like a cork opener and one that is a lever. I found the lever design to be more reliable than the other one.

Watertight Container – exploding bottles are no joke. Aside from the mess (I know from experience), it's also dangerous. I now bottle condition my bottles inside a watertight container to contain any explosions resulting from improper priming (adding a fermentable ingredient to the bottle) or contamination.

Cut apart the pumpkin to access the seeds. Next scoop out the seeds and fiber. Some of the pumpkins were quite large so they were cut in wedges which better fit the pan.

Place the pieces in a tray and cover with foil. I baked them for 1.5 hours total at 400°F the way I prep pumpkins for pie. Maybe because of the size of my pumpkin, they weren’t done at 1 hours so I gave it another 30 minutes until they were soft. I returned them to oven without a cover to be extra sure they were cooked all the way.

Chop the pumpkin (I used a stainless scraper I had) until it is broken up and no longer stringy. Set aside the chopped pumpkin for the next step.

Measure out the grains you need and mill them if they aren’t milled already. The kernels should be broken apart but not ground so fine that they have become flour. Kernels that are not broken enough will not be extracted properly and kernels that are crushed too fine will lead to issues further on.

Mashing or turning the barley into sugary yeast food involves soaking the milled barley and pumpkin in water and holding a specific temperature for an adequate amount of time. Although there are many commercial products to complete this step, I found my stovetop to be satisfactory. It takes some time ~20 minutes before the temperature drops significantly. When that happens, I turn on the burner and stir until the temperature is back where it should be. The advantage of this solution is less stuff to buy and therefore more money to buy ingredients Yay! and less stuff to store Double Yay! It is generally known that the mash temperature affects the body of the beer so for this beer my target temperature was 150°F to 154°F which is the range for a medium bodied beer. This step takes about an hour and is complete when all the starches in the grain and adjuncts are converted into yeast food (sugars). Many recipes call for mashing at different temperatures but the general consensus now is that step or multiple temperature mashing is unnecessary. It is recommended to raise the temperature at the end of the mashing process (mashout) to stop enzymic activity to help the lautering process (more below) but it is more of a concern for commercial brewers as I skipped this step many times and have never had an issue. One way to confirm the completion of the mashing process is to combine some tincture of iodine and the wort (proper name for the water now that it absorbed the stuff from the grains during the mashing process) and checking the color. I stopped doing it since it was messy (stains everything) and time consuming. Instead I check the specific gravity of the wort at the 1 hour mark to see if it reaches a value around the target S.G. If not I continue mashing until it does so.

Also a note on the water: I don’t use bottled or filtered water since I find the tap water to be pleasant enough to drink. If the tap water happens disagreeable or if there is the need to eliminate another variable, go ahead and use bottled water or filter it with a reverse osmosis system. However I have brewed many beers with just tap water which saves money in the long run so give it a shot unless there is something particularly wrong with the water.

With the mashing underway, gathered the spice mix which is responsible for the pumpkin spice character in the beer. I took care of the allspice in my mortar and pestle but since I didn’t have a nutmeg grater, I did my best to shave it with a serrated knife.

Lautering the Grains

Lautering involves straining the wort from the grains. Transfer the grains into the lauter tun. Filling the lauter tun so that the strainer is submerged under an inch or so of water prevents the grains from clogging the strainer and causing the runoff to be “stuck”. This works effectively in floating the grains (zero gravity!) which is especially important in this recipe as the pumpkin mash is inherently prone to clogging. Place a bucket below the lauter tun to catch the runoff. The flow should be adjusted so that the liquid drains slowly with the liquid maintained above the grains until the end of the lautering process. Sparging involves extracting as much of the residual sugars from the grains by running water through the grains. For this step take 4 gallons of water (I use water warm to touch instead of the recommended 170°F and have been able to do this step effectively) and rinse the grain in the lauter tun. The liquid flowing out will be progressively lighter in color due to less and less residual content left in the grain. At some point my runoff bucket was in danger of overflowing so I stopped the flow with the spigot, transferred the liquid to the brew kettle (rinsed of the grain residue) to make more room for the runoff.

Taking the Pre-Boil Specific Gravity

At this point I took the S.G. of the pre boil wort to find the ballpark post boil wort. At 1.040, it is lower than the target S.G. of 1.066. However at the current volume of 8 gallons, once boiled down to 5 gallons, the S.G. becomes 1.064.

1.064 = (8gal/ 5gal) * (1.040 - 1.000) + 1

I usually compost the spent grain in my backyard. There are recipes using it as an ingredient in baked goods which I plan to try in the future.

Measure out the respective quantities of hops for this process. I have a pretty accurate 100g scale which works perfectly for this. I no longer add hops after boiling occurs because of the conclusions of this Brulosophy "Exbeeriment." Instead they go in at the start of the boiling process. Boil the wort until enough water evaporates and the proper volume is reached. This can take several hours depending on the initial quantity of wort. At the end of the boil add the remaining hops and spices before proceeding to the next step.

Adding the Wort Chiller

With the hop oils extracted and wort concentrated from the boiling, the next step is to chill it as quickly as possible before the addition of the yeast. With the wort chiller connected to a water source, drop the chiller into the brew pot. This process can take a while depending on the design of your chiller and the temperature of the hose water. Avoid touching the wort as it drops below boiling since it is prone to contamination as it nears room temperature. In addition everything the wort now comes in contact with should be sanitized.

Watching the Temperature

The speed at which the wort cools slows as the temperature of the wort approaches the temperature of the inlet water. For me this step took the greater part of an hour. The target temperature is usually listed on the packet of yeast and is somewhere around 68F but I haven’t noticed a difference at higher temperatures (90-100°F). Yeast doesn’t die until ~130F so the proper temperature isn't that important.

Checking the Specific Gravity

The specific gravity of the wort (Original Gravity) needs to be determined to find the alcohol content. Since alcohol is lighter than water, an increase of alcohol in the solution will lead to a decrease of density. The exact alcohol content is found by taking the difference of the specific gravities of the wort pre and post fermentation. I achieved a value of 1.060 which is 9% less than the lowest expected original gravity according to the recipe. As a result the alcohol content of the final product will be less than expected. The difference could have been due to the lack of boiling – I had about a gallon of wort left which would have increased the O.G. had the water content been boiled away.

Transferring to the Fermentation Vessel

Connect a sanitized tube from the brew pot to the sanitized fermentation vessel. The spigot to my brew kettle has a barbed fitting that is larger than the hoses I have but I found that the O.D. of the hoses have an almost perfect seal when inserted in the I.D. of the fitting. I throttle the flow to a slow stream and angle the outlet of the hose so the wort can contact as much of the air inside the container as possible. Oxygen is neccessary for proper yeast growth and I have found the steps adequate in providing enough aeration. There are many products to assist with aeration but I have found them unnecessary and they seem likely to cause contamination in the beer. It is usually recommended to pour only the clear portion and to leave the solids (trub) behind but I add everything now after I came across the findings of another Brulosophy “Exbeeriment.”

“Pitch” or pour the contents of your yeast packet into the fermenter. I have used both liquid and dry cultures but I haven’t noticed a difference so I opt for the dry ones which are cheaper and have a better shelf life. A common technique is to dissolve the dry yeast in some water first to "rehydrate" the yeast. I have tried both pitching it straight and rehydrating it but I haven’t noticed a difference so I just pour it straight in.

Blow-off Tube Setup

Since my carboy was almost completely full, I was worried the contents from the fermentation process would overflow beyond the mouth of the carboy. I fashioned a blow off tube with a drilled stopper, hollow rod, and vinyl tubing. The circuitous path also helps to prevent any wild cultures from entering the fermentation vessel.

Storing the Fermentation Vessel

I placed an empty pitcher on an upside down wastebasket to catch any overflow. This process turned out to be unnecessary since the fermentation wasn't as vigorous as I expected.

Early Fermentation

With food to eat (sugars) and something to eat it (yeast) the fermentation process can now begin! Depending on the temperature, vigorous fermentation (looks like a rolling boil) starts in about a day and lasts for three days total. Afterwards the activity slows down although it isn’t really stagnant until the one week mark.

Fermenting Temperature

Recipes will usually specify a temperature to maintain for the duration of the fermentation process. This seems to be more of an issue for lager style beers as ales do fine as long as it is not too cold. I haven’t had any off flavors from fermenting at 80+°F so feel free to experiment with different temperatures. The temperature for this batch averaged at around 78°F and changed a couple degrees depending on the time of day.

Mid Fermentation

Past the initial stage the activity is much diminished. There may be the occasional bubble but the rolling boil of the initial fermentation phase is over. Note that the beer is quite cloudy with a significant amount of solids suspended in the solution.

Fermentation Complete

At the two week mark most properly brewed ales are done with fermentation. I have concluded some earlier at one week but they were simple recipes and fermented at relatively warm temperatures. The beer should be much clearer with the solids settling at the bottom of the vessel.

Commercially available beer is carbonated with industrially sourced CO2 with high pressure equipment. For everyone who is not an avid homebrewer with a kegging system, bottles are the way to go. Bottle conditioning consists of adding some yeast food (usually corn sugar but sometimes malt extract) to the beer before it goes into the bottle and capping it to keep the CO2, a byproduct of fermentation, from escaping the bottle.

Preparing the Priming Sugar

¾ cup of corn sugar is adequate for a 5 gallon batch. Reducing the sugar will result in lightly carbonated beer. Likewise increasing the sugar will cause increased carbonation; however, bottles will fail from too much pressure so it is important to ensure the proper volume is added. Mixing 2 cups of boiling water with 3/4 cup of corn sugar ensures the sugar is fully dissolved and that the solution is sterilized.

Adding the Priming Sugar

With the fermentation vessel higher than the bucket, start a siphon and empty the contents into the bucket below. Instead of stirring the dissolved priming sugar into the uncarbonated beer with a spoon, I like to add the solution to the bucket just after the start of the siphoning. Since the priming solution is scalding, having some of the beer in the bucket prevents the solution from melting the bucket. Also the flow coming from the siphon tube adequately mixes the priming sugar with the beer reducing the need to sanitize another item. The beer should be transferred with minimal disturbance to prevent aerating the beer which may cause respiration instead of fermentation in the yeast.

Filling the Bottles

With some tubing, start filling the bottles with the primed beer. A spigot and a bottle filler streamlines the process as there is no need to start a siphon and less beer is spilled while going from bottle to bottle. The bottles should be filled almost to the top: not all the way as there needs to be some space for CO2 produced from fermentation to reside.

Capping the Bottles

Follow the instructions on your bottle capper. My particular capper has a magnetic crimping tool which holds on to an uncrimped cap. By pulling down on the lever, the cap is squeezed onto the bottle. The rim of the cap becomes deformed in the process thereby holding the cap in place.

Letting the Yeast do its Work (Again)

Before the beer is ready, the beer needs another round of fermenting to build up carbonation in the bottle which results in the fizzy drink we are all accustomed to. This step is called bottle conditioning and is necessary unless a kegging system is used. I do this step in a dark room where I place all the bottles in a watertight container to prevent leaking if any of the bottles decide to explode or if the caps become undone from the pressure. Although I haven’t had a bottle explode in my last batches, it has happened in the past either from overpriming, contamination, or bottling partially fermented beer. From experience this step takes about a week at warm temperatures. Checking for finished beer consists of opening a bottle, pouring it out, and seeing if the carbonation is adequate.

Measuring the Final Specific Gravity

To find out the alcohol content of the beer, it is necessary to do one final check with the hydrometer. Since density changes with temperature, it is important to cool or heat the liquid until it matches the temperature the hydrometer was calibrated at. Also in this case, the bubbles from the carbonation affect the density so I agitated the beer until it was flat. Letting it sit out for long enough will also have the same effect.

Congratulations! Make sure you find some people to share it with.

I found the beer to be similar to the Sierra Nevada Pale Ale. The only complaint was from one person who found it too sweet. Someone else thought it was like a Samuel Adams Boston Lager! Overall it was well received. Unfortunately I couldn't taste the pumpkin although some people said they could. I also had trouble discerning the spices so I would add another helping next time around. It was still refreshing in its own way by not being overly holiday-esque.

Hopefully this has inspired you to brew more traditional or modern all grain beers. Feel free to experiment with different ingredients and techniques. There is no "correct" way to brew beer. With trial and error, you can find a method that works best for you. There are still so many styles I haven't tried yet but I hope this has inspired you to try homebrewing yourself.