Underpitching a Hefeweizen and Saving Yeast

I plan to brew a hefeweizen using Wyeast 3068. From the Wyeast website for 3068, I found this:


I want to lean more towards banana than clove, so I plan to pitch less than the full smack pack, maybe half of it. Should I try to save the rest of the smack pack, perhaps refrigerated in a clean and empty White Labs tube, or just toss it?

If I save it, how long would it still be useable?

Does half a smack pack sound right for a 5-gallon batch, or is too underpitched?

Pitching the whole smack pack would still be under pitching by about half. Pitch the whole thing and wash the yeast when you're done to save yeast.

I would say you would be under pitching just using a smack pack w/ no starter.

Please help me understand. From the Wyeast website:


How is using the whole smack pack underpitching?

If I pitched the whole smack pack in a 2.5-gallon batch, would that be right?

From MrMalty.com:

Here is the simple math to calculate the number of cells needed. For an ale, you want to pitch around 0.75 million cells of viable yeast, for every milliliter of wort, for every degree plato.

(0.75 million) X (milliliters of wort) X (degrees Plato of the wort)

There is about 3785 milliliters in a gallon. There are about 20,000 milliliters in 5.25 gallons
A degree Plato is about 1.004 of original gravity. Just divide the OG by 4 to get Plato (e.g., 1.048 is 12 degrees Plato).


So, for a 1.048 wort pitching into 5.25 gallons you need about 180 billion cells.

(750,000) X (20,000) X (12) = 180,000,000,000

As an easy to remember rough estimate, you need about 15 billion cells for each degree Plato or about 4 billion cells for each point of OG when pitching into a little over 5 gallons of wort. If you want a quick way of doing a back of the envelope estimate, that is really close to 0.75 billion cells for each point of gravity per gallon of wort. Double that to 1.5 billion for a lager

So, <my words now> smack packs have at most 100 billion cells, less depending on production date...a normal ale batch takes 150 - 200 billion cells. So 1 smack pack is underpitching by roughly half

a fresh smack-pack or vial contains 100 billion cells. we rarely buy them that fresh, so the typically contain less than 100B. as mr.malty shows, ideal pitching is 180B so even a rather fresh pack is about half of what you ideally want. use mr. malty to determine what your current yeast count is, based on date. the older the pack/vial, the fewer live cells you'll have in there.

why do wyeast and whitelab claim that one of their packs/vials is enough? they likely want to highlight how easy it is to use their products - open & pitch makes for better marketing than open, make starter with additional equipment, crash overnight, and pitch. there may be technical reasons why they don't want to sell 200B packs (dilute the beer too much? too expensive?).

while less than 100B cells is underpitching, it will rarely ruin the beer. the yeast will be stressed out and might not produce the absolute best beer it potentially could, but it should ferment out (eventually).

but why risk not making the absolute best beer that you can?

smyrnaquince said:

If I pitched the whole smack pack in a 2.5-gallon batch, would that be right?

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smyrnaquince - I got you...only a 2.5G batch. You would need about 84B cells for normal fermentation, which is probably about right for 1 smack pack after calculating viability lost.

BUT - you want to under pitch to gain the banana esters. I pitched half of the recommended amount for WLP300 before, and it was noticeably different with the banana flavor poking out, as compared to the batch that I properly pitched - both at the same fermentation temp of 63.


You'll have a tough time to pour half of the smack pack in....so dump the whole thing into a measurement cup (sanitzed) first, and have the slurry consistenly mixed up, then just pitch half.

Put the rest into a small sanitized jar and stick it in your fridge. That to me would be the best way to hang onto it.

sweetcell said:

while less than 100B cells is underpitching, it will rarely ruin the beer. the yeast will be stressed out and might not produce the absolute best beer it potentially could, but it should ferment out (eventually).

but why risk not making the absolute best beer that you can?

Click to expand...

Sometimes - underpitching is making the best beer you can. Its all in the eye of the beer holder.

All--I didn't know about Mr. Malty. Thanks for that tip and for the discussion. I now understand pitching rates better.

luke2080--Yes, I actually want to brew a stovetop half batch (2.5 gallon into bottles, 2.7-gallon into fermentor). But, I thought the conversation would be easier if I talked about a normal 5-gallon batch in this thread and then just did a divide by two for what I needed.

When I buy the yeast, I will use Mr. Malty to double-check the yeast viability based on the production date.

Roughly speaking, I will pitch half of the smack pack, using your measuring cup suggestion.

I believe .75 million per milliliter per degree plato is too much for a good weiss bier. My last was pitched at about 3 million per milliliter and turned out great. That is less than a healthy smack pack into five gallon. I used a starter for two beers, a hefe pitched at 9 million/ml and a dunkel at 3 million/ml. The dunkel is much better. The hefe is all clove but the dunkel has nice banana too. I would just use a single pack.

i would pitch the whole pack and get your ferm temps in the higher end of what the yeast is rated for. Warmer temps with a hefe yeast give you more banana, cooler brings out the clove. This is what i do with mine and i get the banana to come through well.

Malticulous said:

I believe .75 million per milliliter per degree plato is too much for a good weiss bier. My last was pitched at about 3 million per milliliter and turned out great. That is less than a healthy smack pack into five gallon. I used a starter for two beers, a hefe pitched at 9 million/ml and a dunkel at 3 million/ml. The dunkel is much better. The hefe is all clove but the dunkel has nice banana too. I would just use a single pack.

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Malticulous--Just making sure I understand you. Did you mean to suggest I pitch at 0.3 million/ml for my Hefe? The suggestion of 0.75 million / ml is less than the 3 million/ml of your original text. Thanks.

TyTanium said:

From MrMalty.com:

Here is the simple math to calculate the number of cells needed. For an ale, you want to pitch around 0.75 million cells of viable yeast, for every milliliter of wort, for every degree plato.

Click to expand...

So now my confusion comes from reading Palmer's "How to Brew" print version (c) 2006.

Page 63 says to pitch

• 1 billion cells / liter / 1 degree Plato (roughly agreeing with Mr. Malty)
• 0.95 billion cells / gallon / 1 point (1.001) of gravity

That would give

• 261 points for 5 gallons at 1.055
• 228 points for 5 gallons at 1.048

The contradiction is that on Page 68 in Table 8, he gives the recommended pitching rate for ale yeast as 50-110 billion cells per 5 gallons at <1.055 gravity.

That means that Palmer's table gives a rate at 1/5 to 1/2 of what his formula does. Huh?

That dives into too much math for me.

Use Mr. Malty for your calculation. You can pitch half of the recommended rate to stress them for some banana flavor (which I've done sucessfully) or pitch at a warmer temp like bucfanmike suggested. Either way will work. I've not used WY3068, just WLP300 for this purpose. For 3068 try just tossing in the whole smack pack and fermenting warm. Should work fine.

luke2080 said:

That dives into too much math for me.

Use Mr. Malty for your calculation. You can pitch half of the recommended rate to stress them for some banana flavor (which I've done sucessfully) or pitch at a warmer temp like bucfanmike suggested. Either way will work. I've not used WY3068, just WLP300 for this purpose. For 3068 try just tossing in the whole smack pack and fermenting warm. Should work fine.

Click to expand...

Same strain - agree, just toss the smack pack contents in and let it go. I personally always seem to get bubble gum from this strain (fermenting around 65-68 ). I need to try it upstairs or something to get that banana flavor that SWMBO loves ;-)

watch this video. he talks specifically about your question.

I pitched a 3068 smackpack into a 1.050 OG, 68F wheat wort and it came out with wonderful banana flavours. Now I'm growing a starter from the reused yeast and will see if the cloves come out with a higher pitch rate, although the Wyeast guy says I should have used a 2 L starter instead of a 1 L starter. We'll see...